Circulating tumor-derived DNA (ctDNA) can be used to monitor cancer dynamics noninvasively. Detection of ctDNA can be challenging in patients with low-volume or residual disease, where plasma contains very few tumor-derived DNA fragments. We show that sensitivity for ctDNA detection in plasma can be improved by analyzing hundreds to thousands of mutations that are first identified by tumor genotyping. We describe the INtegration of VAriant Reads (INVAR) pipeline, which combines custom error-suppression methods and signal-enrichment approaches based on biological features of ctDNA. With this approach, the detection limit in each sample can be estimated independently based on the number of informative reads sequenced across multiple patient-specific loci. We applied INVAR to custom hybrid-capture sequencing data from 176 plasma samples from 105 patients with melanoma, lung, renal, glioma, and breast cancer across both early and advanced disease. By integrating signal across a median of >105 informative reads, ctDNA was routinely quantified to 1 mutant molecule per 100,000, and in some cases with high tumor mutation burden and/or plasma input material, to individual parts per million. This resulted in median Area Under the Curve (AUC) values of 0.98 in advanced cancers, and 0.80 in early stage and challenging settings for ctDNA detection. We generalized this method to whole-exome and whole-genome sequencing, showing that the INVAR may be applied without requiring personalized sequencing panels, so long as a tumor mutation list is available. As tumor sequencing becomes increasingly performed, such methods for personalized cancer monitoring may enhance the sensitivity of cancer liquid biopsies.
Many studies over the past 10 years, culminating in the recent report of the International Stem Cell Initiative (ISCI, 2011) have shown that hPSC acquire genetic and epigenetic changes during their time in culture. Many of the genetic changes are non-random and recurrent, probably because they provide a selective growth advantage to the undifferentiated cells. Some are shared by embryonal carcinoma cells, the malignant counterparts of ES cells. The origins of these growth advantages are poorly understood, but may come from altered cell cycle dynamics, resistance to apoptosis or altered patterns of differentiation. Less is known about the nature and consequences of epigenetic changes, but it is likely that these similarly affect hPSC behaviour; e.g., enhanced expression of DLK1, an imprinted gene, is associated with altered hPSC growth (Enver et al 2005). Inevitably, these genetic and epigenetic changes will impact on our ability to use hPSC for regenerative medicine, either because malignant transformation of the undifferentiated cells or their differentiated derivatives to be used for transplantation compromises safety, or because they impede the function of those differentiated derivatives, or because they affect the efficiency with which the undifferentiated cells can be expanded and differentiated into desired cell types. Focusing initially upon the existing clinical grade hESC lines, later moving to iPSC, we will Consolidate and extend knowledge of the rate, type and functional impact of the genetic variations that occur during hPSC culture. We will use whole genome and exome sequencing as well as SNP arrays, together with clonal analysis and other cytogenetics techniques. Common changes will be compared with those found in the normal human population, at low frequency in the original cell population or observed during iPSC generation in the HIPSCI project currently based at the WTSI. These studies will provide a better understanding of the range of genetic changes that occur in hPSC beyond the CNVs already identified. In conjunction with cancer genome resources and expertise at WTSI, bioinformatic analyses of these hPSC data will allow us to assess potential impact on hPSC behaviour pertinent to applications in regenerative medicine, notably the likelihood that specific changes arising in undifferentiated PSC cultures may be associated with potential malignant transformation of differentiated progenyThis data is part of a pre-publication release. For information on the proper use of pre-publication data shared by the Wellcome Trust Sanger Institute (including details of any publication moratoria), please see http://www.sanger.ac.uk/datasharing/
Many studies over the past 10 years, culminating in the recent report of the International Stem Cell Initiative (ISCI, 2011) have shown that hPSC acquire genetic and epigenetic changes during their time in culture. Many of the genetic changes are non-random and recurrent, probably because they provide a selective growth advantage to the undifferentiated cells. Some are shared by embryonal carcinoma cells, the malignant counterparts of ES cells. The origins of these growth advantages are poorly understood, but may come from altered cell cycle dynamics, resistance to apoptosis or altered patterns of differentiation. Less is known about the nature and consequences of epigenetic changes, but it is likely that these similarly affect hPSC behaviour; e.g., enhanced expression of DLK1, an imprinted gene, is associated with altered hPSC growth (Enver et al 2005). Inevitably, these genetic and epigenetic changes will impact on our ability to use hPSC for regenerative medicine, either because malignant transformation of the undifferentiated cells or their differentiated derivatives to be used for transplantation compromises safety, or because they impede the function of those differentiated derivatives, or because they affect the efficiency with which the undifferentiated cells can be expanded and differentiated into desired cell types. Focusing initially upon the existing clinical grade hESC lines, later moving to iPSC, we will Consolidate and extend knowledge of the rate, type and functional impact of the genetic variations that occur during hPSC culture. We will use whole genome and exome sequencing as well as SNP arrays, together with clonal analysis and other cytogenetics techniques. Common changes will be compared with those found in the normal human population, at low frequency in the original cell population or observed during iPSC generation in the HIPSCI project currently based at the WTSI. These studies will provide a better understanding of the range of genetic changes that occur in hPSC beyond the CNVs already identified. In conjunction with cancer genome resources and expertise at WTSI, bioinformatic analyses of these hPSC data will allow us to assess potential impact on hPSC behaviour pertinent to applications in regenerative medicine, notably the likelihood that specific changes arising in undifferentiated PSC cultures may be associated with potential malignant transformation of differentiated progeny. This data is part of a pre-publication release. For information on the proper use of pre-publication data shared by the Wellcome Trust Sanger Institute (including details of any publication moratoria), please see http://www.sanger.ac.uk/datasharing/
Many studies over the past 10 years, culminating in the recent report of the International Stem Cell Initiative (ISCI, 2011) have shown that hPSC acquire genetic and epigenetic changes during their time in culture. Many of the genetic changes are non-random and recurrent, probably because they provide a selective growth advantage to the undifferentiated cells. Some are shared by embryonal carcinoma cells, the malignant counterparts of ES cells. The origins of these growth advantages are poorly understood, but may come from altered cell cycle dynamics, resistance to apoptosis or altered patterns of differentiation. Less is known about the nature and consequences of epigenetic changes, but it is likely that these similarly affect hPSC behaviour; e.g., enhanced expression of DLK1, an imprinted gene, is associated with altered hPSC growth (Enver et al 2005). Inevitably, these genetic and epigenetic changes will impact on our ability to use hPSC for regenerative medicine, either because malignant transformation of the undifferentiated cells or their differentiated derivatives to be used for transplantation compromises safety, or because they impede the function of those differentiated derivatives, or because they affect the efficiency with which the undifferentiated cells can be expanded and differentiated into desired cell types. Focusing initially upon the existing clinical grade hESC lines, later moving to iPSC, we will Consolidate and extend knowledge of the rate, type and functional impact of the genetic variations that occur during hPSC culture. We will use whole genome and exome sequencing as well as SNP arrays, together with clonal analysis and other cytogenetics techniques. Common changes will be compared with those found in the normal human population, at low frequency in the original cell population or observed during iPSC generation in the HIPSCI project currently based at the WTSI. These studies will provide a better understanding of the range of genetic changes that occur in hPSC beyond the CNVs already identified. In conjunction with cancer genome resources and expertise at WTSI, bioinformatic analyses of these hPSC data will allow us to assess potential impact on hPSC behaviour pertinent to applications in regenerative medicine, notably the likelihood that specific changes arising in undifferentiated PSC cultures may be associated with potential malignant transformation of differentiated progeny. This data is part of a pre-publication release. For information on the proper use of pre-publication data shred by the Wellcome Trust Sanger Institute (including details of any publication moratoria), please see http://www.sanger.ac.uk/datasharing/
Andersen-Tawil syndrome (ATS) is an ion channel disorder that causes episodes of muscle weakness and potentially life-threatening heart arrhythmias. The majority of ATS cases are caused by a mutation in the KCNJ2 gene, which is linked to potassium channels in the heart, brain, and skeletal muscle; other cases are presumed to be caused by an undetermined gene lesion. To date, the treatment for ATS has been largely anecdotal, and no treatments have been formally assessed in a controlled clinical trial. This study will determine whether potassium supplements and/or acetazolamide, which is a diuretic medication, affect the duration of muscle weakness and heart rhythm abnormalities in people with ATS. Participation in this study will last about 11 months. Participants will first attend a 3-day inpatient visit that will include a medical history, physical examination, blood work, heart rhythm testing by an electrocardiogram (ECG) and Holter monitor, strength testing, a health questionnaire, and daily potassium supplementation. Participants will also track the number and length of weakness episodes that they experience while in the hospital. On the last day of the inpatient visit, participants will be provided with multiple bottles containing either potassium or placebo. Participants will then return home for an 18-week treatment period that will consist of six 3-week-long treatments of either potassium or placebo, with the treatment schedule being randomly determined. Upon completing the first 18-week treatment period, participants will attend a second 3-day inpatient visit that will include the same tests and procedures as the first. The only difference will be that participants will receive acetazolamide along with potassium. This will be followed by a second 18-week treatment period that will consist of six 3-week-long treatments of either acetazolamide or placebo. At the end of the second treatment period, participants will fill out another health questionnaire. Throughout both 18-week treatment periods, participants will phone in daily to track any muscle or heart problems. They will also provide blood samples on a weekly basis. At Weeks 2, 5, 8, 11, 14, and 17 of both treatment periods, participants will wear a Holter monitor for 24 hours and then mail it in. A final outpatient visit will occur 8 weeks after the end of the second treatment period and will include heart rhythm testing, muscle strength testing, and blood work.
Follicular lymphoma (FL) exhibits considerable variability in biological features and clinical trajectories across patients. To dissect the diversity of FL, we utilized a Bernoulli mixture model to identify genetic subtypes in 713 pre-treatment tumor tissue samples. Our analysis revealed the existence of five subtypes with unique genetic profiles that correlated with clinicopathological characteristics. The clusters were enriched in specific mutations as follows: CS (CREBBP and STAT6), TT (TNFAIP3 and TP53), GM (GNA13 and MEF2B), Q (quiescent, for low mutation burden), and AR (mutations of mTOR pathway-related genes). The subtype Q was enriched for patients with stage I disease and was associated with a lower proliferative history compared to the other subtypes. The AR subtype was unique in its enrichment for IgM-expressing FL cases and was associated with advanced-stage and more than 4 nodal sites. The existence of subtypes was validated in an independent cohort of 418 samples from the GALLIUM trial. Notably, patients assigned to the TT subtype consistently experienced inferior progression-free survival when treated with immunochemotherapy. Collectively, our findings offer insight into core pathways distinctly linked with each FL cluster and are expected to be informative in the era of targeted therapies.
The goal of this study was to explore extracellular vesicles (EVs) from human tears and iPSC-derived RPE cells as biomarkers for Usher syndrome type 1B (USH1B), a rare inherited disorder causing deafness and retinitis pigmentosa. Researchers found that tear EVs showed higher levels and diversity of miRNAs, making them a promising non-invasive source for diagnosing USH1B. In contrast to patient-derived RPE cells, which did not express MYO7A protein despite similar expression levels in controls, the study identified specific microRNA signatures associated with retinal degeneration in both tear EVs and RPE-derived EVs. The findings suggest that tear EVs can serve as a useful biomarker for USH1B diagnosis, monitoring, and therapeutic development. Overall, this research aims to contribute to our understanding of disease mechanisms and identify potential targets for treatment in patients with Usher syndrome type 1B.
Chronic lymphocytic leukemia (CLL) is characterized by substantial clinical heterogeneity, despite relatively few genetic alterations. To provide a basis for studying epigenome deregulation in CLL, we established genome-wide chromatin accessibility maps for 88 CLL samples from 55 patients using the ATAC-seq assay, and we also performed ChIPmentation and RNA-seq profiling for ten representative samples. Based on the resulting dataset, we devised and applied a bioinformatic method that links chromatin profiles to clinical annotations. Our analysis identified sample-specific variation on top of a shared core of CLL regulatory regions. IGHV mutation status – which distinguishes the two major subtypes of CLL – was accurately predicted by the chromatin profiles, and gene regulatory networks inferred for IGHV-mutated vs. IGHV-unmutated samples identified characteristic differences between these two disease subtypes. In summary, we discovered widespread heterogeneity in the chromatin landscape of CLL, established a community resource for studying epigenome deregulation in leukemia, and demonstrated the feasibility of chromatin accessibility mapping in cancer cohorts and clinical research.
Gradual accumulation of mutations in human adult stem cells during life is associated with various age-related diseases, including cancer. The number of stem cell divisions throughout life is believed to be a major determinant for mutation accumulation and could explain the extreme variation of cancer incidence across different organs. Yet, mutation patterns and rates of healthy adult stem cells remain unknown. Here, we determined genome-wide mutation patterns in primary adult stem cells of the small intestine, colon and liver of human donors with ages ranging from 3 to 87 years. We find that the number of mutations increases linearly with age up to several thousand mutations per cell at 87 years of age, while mutation spectra remain constant throughout life. Small intestine and colon stem cells have a 2-fold higher mutation rate per year compared with liver stem cells. These differences could be exclusively attributed to the mutagenic action of spontaneous deamination of cytosine residues and may reflect the high stem cell division rate in these tissues. The genomic distribution of somatic mutations is non-random and predominantly associated with DNA replication dynamics in the small intestine and colon, and with transcription in the liver. These results indicate that a stable balance between various mutagenic and DNA repair processes is maintained throughout life and that the activity of these processes in adult stem cells varies between tissues.
The Genetics and Epidemiology of Colorectal Cancer Consortium (GECCO) is a collaborative effort comprised of a coordinating center and scientific researchers from well-characterized cohort and case-control studies conducted in North America and Europe. This international consortium aims to accelerate the discovery of common and rare genetic risk variants for colorectal cancer by conducting large-scale meta-analyses of existing and newly generated genome-wide association study (GWAS) data, replicating and fine-mapping of GWAS discoveries, and investigating how genetic risk variants are modified by environmental risk factors. To expand these efforts, we assembled case-control sets or nested case-control sets from 20 different North American or European studies. Summary descriptions and study participant inclusions/exclusion criteria for each of these studies are detailed below. The Black Women's Health Study (BWHS): Is the largest follow-up study of the health of African-American women (Cozier et al., 2004; Rosenberg et al., 1995) [PMID: 15018884; PMID: 7722208]. The purpose is to identify and evaluate causes and preventives of cancers and other serious illnesses in African-American women. Among the diseases being studied are breast cancer, colorectal cancer, type 2 diabetes, uterine fibroids, systemic lupus erythematosus, and cardiovascular disease. The study began in 1995, when 59,000 black women from all parts of the United States enrolled through postal questionnaires. The women provided demographic and health data on the 1995 baseline questionnaire, including information on weight, height, smoking, drinking, contraceptive use, use of other selected medications, illnesses, reproductive history, physical activity, diet, use of health care, and other factors. The participants are followed through biennial questionnaires to determine the occurrence of cancers and other illnesses and to update information on risk factors. Self-reports of cancer are confirmed through medical records and state cancer registry records. Mouthwash-swish samples, as a source of DNA, were obtained from ~26,000 BWHS participants in 2002-2007. DNA was isolated from the mouthwash-swish samples at the Boston University Molecular Core Genetics Laboratory using the QIAAMP DNA Mini Kit (Qiagen). All incident colorectal cancer cases with a DNA sample were included in the present analysis. Two controls per case, selected from among BWHS participants free of colorectal cancer at end of follow-up, were matched to cases on year of birth (+/- 2 years) and geographical region of residence (Northeast, South, Midwest, and West). A total 209 colorectal cancer cases and 423 controls were sent for genotyping. Campaign Against Cancer and Heart Disease (CLUE II): The Campaign Against Cancer and Heart Disease, is a prospective cohort designed to identify biomarkers and other factors associated with risk of cancer, heart disease, and other conditions (Kakourou et al., 2015) [PMID: 26220152]. 32,894 participants were recruited from May through October 1989 from Washington County, Maryland and surrounding communities. Colorectal cancer cases (n = 297) and matched controls (n = 296) were identified between 1989 and 2000 among participants in the CLUE II cohort of Washington County, Maryland. Colorectal Cancer Study of Austria (CORSA): In the ongoing colorectal cancer study of Austria (CORSA), more than 13,000 Caucasian participants have been recruited within the province-wide screening project "Burgenland Prevention Trial of Colorectal Disease with Immunological Testing" (B-PREDICT) since 2003 (Hofer et al., 2011) [PMID: 21422235]. All inhabitants of the Austrian province Burgenland aged between 40 and 80 years are annually invited to participate in fecal immunochemical testing and haemoccult positive screening participants are invited for colonoscopy. CORSA includes genomic DNA and plasma of colorectal cancer cases, low-risk and high-risk adenomas, and colonoscopy-negative controls. Controls received a complete colonoscopy and were free of colorectal cancer or polyps. CORSA participants have been recruited in the four KRAGES hospitals in Burgenland, Austria, and additionally, at the Medical University of Vienna (Department of Surgery), the Viennese hospitals "Rudolfstiftung" and the "Sozialmedizinisches Zentrum Sud", and at the Medical University of Graz (Department of Internal Medicine). 1403 colorectal cancer and advanced colorectal adenoma cases, and 1404 matched controls were selected for the study. Distribution of factors sex and age (5 year strata) were evenly matched between cases and controls. Cancer Prevention Study II (CPS II): The CPS II Nutrition cohort is a prospective study of cancer incidence and mortality in the United States, established in 1992 and described in detail elsewhere (Calle et al., 2002; Campbell et al., 2014) [PMID: 12015775; PMID: 25472679]. At enrollment, participants completed a mailed self-administered questionnaire including information on demographic, medical, diet, and lifestyle factors. Follow-up questionnaires to update exposure information and to ascertain newly diagnosed cancers were sent biennially starting in 1997. Reported cancers were verified through medical records, state cancer registry linkage, or death certificates. The Emory University Institutional Review Board approves all aspects of the CPS II Nutrition Cohort. A total of 360 cases and 359 controls were selected for this study. Czech Republic Colorectal Cancer Study (Czech Republic CCS): Cases with positive colonoscopy results for malignancy, confirmed by histology as colon or rectal carcinomas, were recruited between September 2003 and May 2012 in several oncological departments in the Czech Republic (Prague, Pilsen, Benesov, Brno, Liberec, Ples, Pribram, Usti and Labem, and Zlin). Two control groups, sampled at the same time of cases recruitment, were included in the study. The first group consisted of hospital-based individuals with a negative colonoscopy result for malignancy or idiopathic bowel diseases. The reasons for the colonoscopy were: i) positive fecal occult blood test, ii) hemorrhoids, iii) abdominal pain of unknown origin, and iv) macroscopic bleeding. The second control group consisted of healthy blood donor volunteers from a blood donor center in Prague. All individuals were subjected to standard examinations to verify the health status for blood donation and were cancer-free at the time of the sampling. Details of CRC cases and controls have been reported previously (Vymetalkova et al., 2014; Naccarati et al., 2016; Vymetalkova et al., 2016) [PMID: 24755277; PMID: 26735576; PMID: 27803053]. All subjects were informed and provided written consent to participate in the study. They approved the use of their biological samples for genetic analyses, according to the Declaration of Helsinki. The design of the study was approved by the Ethics Committee of the Institute of Experimental Medicine, Prague, Czech Republic. All subjects included in the study were Caucasians and comprised 1792 cases and 1764 matched controls. Controls were matched to CRC cases as 1:1 ratio. Matching was done on age and sex. Age was matched on +-5 years, whereas sex was matched exactly. For the cases without matched controls, matching was done only on sex. Early Detection Research Network (EDRN): The aim of the EDRN initiative is to develop and sustain a biorepository for support of translational research (Amin et al., 2010) [PMID: 21031013]. High-quality biospecimens were accrued and annotated with pertinent clinical, epidemiologic, molecular and genomic information. A user-friendly annotation tool and query tool was developed for this purpose. The various components of this annotation tool include: CDEs are developed from the College of American Pathologists (CAP) Cancer Checklists and North American Association of Central Cancer Registries (NAACR) standards. The CDEs provides semantic and syntactic interoperability of the data sets by describing them in the form of metadata or data descriptor. A total of 352 colorectal case samples and 399 controls were selected for this study. Controls were matched to CRC cases based on age and sex. The EPICOLON Consortium (EPICOLON): The EPICOLON Consortium comprises a prospective, multicentre and population-based epidemiology survey of the incidence and features of CRC in the Spanish population (Fernandez-Rozadilla et al., 2013) [PMID: 23350875]. Cases were selected as patients with de novo histologically confirmed diagnosis of colorectal adenocarcinoma. Patients with familial adenomatous polyposis, Lynch syndrome or inflammatory bowel disease-related CRC, and cases where patients or family refused to participate in the study were excluded. Hospital-based controls were recruited through the blood collection unit of each hospital, together with cases. All of the controls were confirmed to have no history of cancer or other neoplasm and no reported family history of CRC. Controls were randomly selected and matched with cases for hospital, sex and age (+- 5 years). A total of 370 cases and 370 controls were selected for genotyping. Hawaii Adenoma Study: For this adenoma study, two flexible-sigmoidoscopy screening clinics were first used to recruit participants on Oahu, Hawaii. Adenoma cases were identified either from the baseline examination at the Hawaii site of the Prostate Lung Colorectal and Ovarian cancer screening trial during 1996-2000 or at the Kaiser Permanente Hawaii's Gastroenterology Screening Clinic during 1995-2007. In addition, starting in 2002 and up to 2007, we also approached for recruitment all eligible patients who underwent a colonoscopy in the Kaiser Permanente Hawaii Gastroenterology Department. Cases were patients with histologically confirmed first-time adenoma(s) of the colorectum and were of Japanese, Caucasian or Hawaiian race/ethnicity. Controls were selected among patients with a normal colorectum and were individually matched to the cases on age at exam, sex, race/ethnicity, screening date (+-3 months) and clinic and type of examination (colonoscopy or flexible sigmoidoscopy). We recruited 1016 adenoma cases (67.8% of all eligible) and 1355 controls (69.2% of all eligible); 889 cases and 1169 controls agreed to give a blood and 29 cases and 34 controls, a mouthwash sample. A total of 989 cases and 1185 controls were genotyped for this study. Columbus-area HNPCC Study (HNPCC, OSUMC): Patients with colorectal adenocarcinoma diagnosed at six participating hospitals were eligible for this study, regardless of age at diagnosis or family history of cancer. Patients with a clinical diagnosis of familial adenomatous polyposis were not eligible for this study. These six hospitals perform the vast majority of all operations for CRC in the Columbus metropolitan area (population 1.7 million). The institutional review board at all participating hospitals approved the research protocol and consent form in accordance with assurances filed with and approved by the United States Department of Health and Human Services. Briefly, during the period of January 1999 through August 2004, 1,566 eligible patients with CRC were accrued to the study (Hampel et al., 2008) [PMID 18809606]. A total of 1472 colorectal cancer samples had enough blood DNA remaining to be sent for genotyping. Control samples were provided by the Ohio State University Medical Center%#39;s (OSUMC) Human Genetics Sample Bank. The Columbus Area Controls Sample Bank is a collection of control samples for use in human genetics research that includes both donors' anonymized biological specimens and linked phenotypic data. The data and samples are collected under the protocol "Collection and Storage of Controls for Genetics Research Studies", which is approved by the Biomedical Sciences Institutional Review Board at OSUMC. Recruitment takes place in OSUMC primary care and internal medicine clinics. If individuals agree to participate, they provide written informed consent, complete a questionnaire that includes demographic, medical and family history information, and donate a blood sample. 4-7 ml of blood is drawn into each of 3 ACD Solution A tubes and is used for genomic DNA extraction and the establishment of an EBV-transformed lymphoblastoid cell culture, cell pellet in Trizol, and plasma. Controls were matched to CRC cases as 1:1. Matching was done on age at reference time (age_ref), race, and sex. Age_ref was matched on +-5 years. Sex and race were matched exactly. For the cases without matched controls, matching was done only on sex and race with 1:1 ratio. Since controls are fewer than cases, one control is matched on 2 cases at most. Health Professionals Follow-up Study (HPFS): A parallel prospective study to the NHS (Nurses' Health Study). The HPFS cohort comprised 51,529 men aged 40-75 who, in 1986, responded to a mailed questionnaire (Rimm et al., 1990) [PMID: 2090285]. Participants provided information on health related exposures, including current and past smoking history, age, weight, height, diet, physical activity, aspirin use, and family history of colorectal cancer. Colorectal cancer and other outcomes were reported by participants or next-of-kin and were followed up through review of the medical and pathology record by physicians. Overall, more than 97% of self-reported colorectal cancers were confirmed by medical record review. Information was abstracted on histology and primary location. Incident cases were defined as those occurring after the subject provided the blood sample. Prevalent cases were defined as those occurring after enrollment in the study but before the subject provided the blood sample. Follow-up evaluation has been excellent, with 94% of the men responding to date. Colorectal cancer cases were ascertained through January 1, 2008. In 1993-1995, 18,825 men in the HPFS mailed blood samples by overnight courier, which were aliquoted into buffy coat and stored in liquid nitrogen. In 2001-2004, 13,956 men in the HPFS who had not provided a blood sample previously mailed in a swish-and-spit sample of buccal cells. Incident cases were defined as those occurring after the subject provided a blood or buccal sample. Prevalent cases were defined as those occurring after enrollment in the study in 1986, but before the subject provided either a blood or buccal sample. After excluding participants with histories of cancer (except nonmelanoma skin cancer), ulcerative colitis, or familial polyposis, case-control sets were previously constructed. In addition to colorectal cancer cases and controls, a set of adenoma cases and matched controls with available DNA from buffy coat were selected for genotyping. Over the follow-up period, data were collected on endoscopic screening practices and, if individuals had been diagnosed with a polyp, the polyps were confirmed to be adenomatous by medical record review. Adenoma cases were ascertained through January 1, 2008. A separate case-control set was constructed of participants diagnosed with advanced adenoma matched to control participants who underwent a lower endoscopy in the same time period and did not have an adenoma. Advanced adenoma was defined as an adenoma 1 cm or larger in diameter and/or with tubulovillous, villous, or highgrade dysplasia/carcinoma-in-situ histology. Matching criteria included year of birth (within 1 year) and month/ year of blood sampling (within 6 months), the reason for their lower endoscopy (screening, family history, or symptoms), and the time period of any prior endoscopy (within 2 years). Controls matched to cases with a distal adenoma either had a negative sigmoidoscopy or colonoscopy examination, and controls matched to cases with proximal adenoma all had a negative colonoscopy. In total, 159 advanced adenoma cases and 109 controls were selected for genotyping. Leeds Colorectal Cancer Study (LCCS): Following local ethical approval, colorectal cancer cases were recruited from 1997 until 2012 in Leeds, UK through surgical clinics. Initially, funding was provided by the UK Ministry of Agriculture, Farming and Fisheries (subsequently the Food Standards Agency) and Imperial Cancer Research Fund (subsequently Cancer Research UK). Recruitment also occurred similarly in Dundee, Perth and York between the periods of 1997 and 2001 using the same protocol and the data and samples were combined. Pathologically confirmed cases were consented at outpatient clinics, providing information on known and postulated risk factors for colorectal cancer (diet, lifestyle and family history) as well as providing a blood sample for DNA. Exclusion criteria included pre-existing diverticular disease and an inability to complete the questionnaire. The General Practitioners of cases (all UK residents have a nominated General Practitioner to whom to refer initial medical queries) and these GPs were asked to send letters to other persons on their patient list of the same gender and born within 5 years of the case. Subsequently to enhance the number of controls, we systematically invited patients from selected GP practices. Diet was assessed in cases and controls using an extensive dietary and lifestyle questionnaire modified by that produced by the European Prospective Investigation in Cancer (EPIC). The frequency that each specific food items were eaten was recorded and we also obtained average fruit and vegetable consumption as a cross-check. In total, 1591 cases and 739 controls provided a DNA sample. The North Carolina Colon Cancer Studies (NCCCS I/II): The North Carolina Colon Cancer Studies (NCCCS I- colon and NCCCS II-rectal) were population-based case-control studies conducted in 33 counties of North Carolina. Cases were identified using the rapid case ascertainment system of the North Carolina Central Cancer Registry. Patients with a first diagnosis of histologically confirmed invasive adenocarcinoma of the colon (cecum through sigmoid colon) between October 1996 and September 2000 were classified as potential cases in the NCCCS I. The NCCCS II included patients with a first diagnosis of histologically confirmed invasive adenocarcinoma of the sigmoid colon, rectosigmoid, or rectum (hereafter collectively referred to as rectal cancer) between May 2001 and September 2006. Additional eligibility requirements were: aged 40-80 years, residence in one of the 33 counties, ability to give informed consent and complete an interview, had a driver's license or identification card issued by the North Carolina Department of Motor Vehicles (if under the age of 65), and had no objections from the primary physician in regards to contacting the individual. Controls, identified and sampled during the respective study dates, were selected from two sources. Potential controls under the age of 65 were identified using the North Carolina Department of Motor Vehicles records. For those 65 years and older, records from the Center for Medicare and Medicaid Services were used. Controls were matched to cases using randomized recruitment strategies. Recruitment probabilities were done using strata of 5-year age, sex, and race groups. Dietary information was collected using a modified version of the semiquantitative food frequency questionnaire developed at the National Cancer Institute. In addition, participants were asked about vitamin and mineral supplementation, special diets, restaurant eating, sodium use, and fats used in cooking. In NCCCS I, 515 colorectal cases and 687 matched controls were sent for genotyping. In NCCCS II, 796 colorectal cases and 823 controls were sent from the NCCCS II for genotyping. Controls were matched to CRC cases as 1:1 ratio. Matching was done on age, race, and sex. Age was matched on +-5 years. Race and sex was matched exactly. For the cases without matched controls, matching was done only on sex and race. Nurses Health Study (NHS): The NHS cohort began in 1976 when 121,700 married female registered nurses age 30-55 years returned the initial questionnaire that ascertained a variety of important health-related exposures (Belanger et al., 1978) [PMID: 248266]. Since 1976, follow-up questionnaires have been mailed every 2 years. Colorectal cancer and other outcomes were reported by participants or next-of-kin and followed up through review of the medical and pathology record by physicians. Overall, more than 97% of self-reported colorectal cancers were confirmed by medical-record review. Information was abstracted on histology and primary location. The rate of follow-up evaluation has been high: as a proportion of the total possible follow-up time, follow-up evaluation has been more than 92%. Colorectal cancer cases were ascertained through June 1, 2008. In 1989 -1990, 32,826 women in NHS I mailed blood samples by overnight courier, which were aliquoted into buffy coat and stored in liquid nitrogen. In 2001-2004, 29,684 women in NHS I who did not previously provide a blood sample mailed a swish-and-spit sample of buccal cells. Incident cases were defined as those occurring after the subject provided a blood or buccal sample. Prevalent cases were defined as those occurring after enrollment in the study in 1976 but before the subject provided either a blood or buccal sample. After excluding participants with histories of cancer (except nonmelanoma skin cancer), ulcerative colitis, or familial polyposis, case-control sets were previously constructed from which DNA was isolated from either buffy coat or buccal cells for genotyping. In addition to colorectal cancer cases and controls, a set of advanced adenoma cases and matched controls with available DNA from buffy coat were selected for genotyping. Over the follow-up period, data were collected on endoscopic screening practices and, if individuals had been diagnosed with a polyp, the polyps were confirmed to be adenomatous by medical record review. Adenoma cases were ascertained through June 1, 2011. A separate case-control set was constructed of participants diagnosed with advanced adenoma matched to control participants who underwent a lower endoscopy in the same time period and did not have an adenoma. Advanced adenoma was defined as an adenoma more than 1 cm in diameter and/or with tubulovillous, villous, or high-grade dysplasia/carcinoma-in-situ histology. Matching criteria included year of birth (within 1 year) and month/year of blood sampling (within 6 months), the reason for their lower endoscopy (screening, family history, or symptoms), and the time period of any prior endoscopy (within 2 years). Controls matched to cases with a distal adenoma either had a negative sigmoidoscopy or colonoscopy examination, and controls matched to cases with proximal adenoma all had a negative colonoscopy. A total of 272 cases and 236 matched controls were sent to CIDR for the advanced adenoma case-control set. Northern Swedish Health and Disease Study (NSHDS): Comprises over 110,000 participants, including approximately one third with repeated sampling occasions, from three population-based cohorts (Dahlin et al., 2010; Myte et al., 2016) [PMID: 20197478; PMID: 27367522]. The largest is the ongoing Vasterbotten Intervention Programme, in which all residents of Vasterbotten County are invited to a health examination upon turning 30 (some years), 40, 50 and 60 years of age. Extensive measured and self-reported health and lifestyle data, as well as blood samples for central biobanking in Umea, Sweden, are collected at the health exam. Leucocyte DNA samples for 1:1-matched CRC case-control sets from the NSHDS, of which 878 samples are included in this study, have been selected for genotyping. This is in addition to 354 samples from the NSHDS previously analyzed as part of the multicenter EPIC cohort. Cancer-specific and overall survival data are available for all patients. For at least 425 patients, archival tumor tissue has been analyzed for the BRAF V600E mutation and by sequencing codon 12 and 13 for KRAS mutations, as well as for MSI screening status by immunohistochemistry and for an eight-gene CIMP panel using quantitative real-time PCR (MethyLight). Ohio Colorectal Cancer Prevention Initiative (OCCPI, OSUMC): OCCPI (ClinicalTrials.gov identifier: NCT01850654) is a population-based study of colorectal cancer patients diagnosed in one of 51 hospitals throughout the state of Ohio from January 1, 2013 through December 31, 2016. The OCCPI was created to decrease CRC incidence in Ohio by identifying patients with hereditary predisposition (statewide universal tumor screening for newly diagnosed CRC patients), increase colonoscopy compliance for first-degree relatives of CRC patients, and encourage future research through the creation of a biorepository. The 51 Ohio hospitals participating in the OCCPI were selected to represent a cross-section of clinical centers in the state based on high reported volume of CRC patients, affiliation with a high volume hospital, or interest in participation. Institutional Review Board (IRB) approval was obtained by the individual hospitals, Community Oncology Programs, or by ceding review to the OSU IRB. Written informed consent was obtained. A total of 2139 colorectal cases were genotyped. Patients were considered eligible for this study if they were age 18 or older at the time of enrollment, if they had a surgical resection (or biopsy if unresectable) in the state of Ohio demonstrating an adenocarcinoma of the colorectum from 1/1/13 - 12/31/16. Matched control samples were selected from the Ohio State University Medical Center's (OSUMC) Human Genetics Sample Bank in an identical way to the selection for the Columbus-area HNPCC Study (please refer to the description for the Columbus-area HNPCC Study). Prostate, Lung, Colorectal and Ovarian Cancer Screening Trail (PLCO): PLCO enrolled 154,934 participants (men and women, aged between 55 and 74 years) at ten centers into a large, randomized, two-arm trial to determine the effectiveness of screening to reduce cancer mortality. Sequential blood samples were collected from participants assigned to the screening arm. Participation was 93% at the baseline blood draw. In the observational (control) arm, buccal cells were collected via mail using the "swish-and-spit" protocol and participation rate was 65%. Details of this study have been previously described (Huang et al., 2016) [PMID: 27673363] and are available online (http://dcp.cancer.gov/plco). For this study 1651 advanced adenoma cases and 1392 controls were selected for genotyping. Selenium and Vitamin E Prevention Trial (SELECT): The Selenium and Vitamin E Cancer Prevention Trial (SELECT) was a double-blind, placebo controlled clinical trial which explored using selenium and vitamin E alone and in combination to prevent prostate cancer in healthy men (Lippman et al., 2009) [PMID: 19066370]. Secondary endpoints included the prevention of colorectal and lung cancers. SELECT was conducted at 427 sites and centers in the United States, Canada and Puerto Rico; 35,533 men 55 years and older (50 or older if African American) were randomized beginning August 22, 2001. Supplementation was discontinued on October 23, 2008 due to futility. 308 colorectal cancer cases and 308 matched controls were selected from the SELECT population and sent for genotyping. Screening Markers For Colorectal Disease Study and Colonoscopy and Health Study (SMS-REACH): Details on this study population were previously reported (Burnett-Hartman et al., 2014) [PMID: 24875374]. Participants were enrollees in an integrated health-care delivery system in western Washington State (Group Health Cooperative, Seattle, Washington) aged 24-79 years who underwent an index colonoscopy for any indication between 1998 and 2007 and donated a buccal-cell or blood sample for genotyping analysis. Study recruitment took place in 2 phases, with phase 1 occurring in 1998-2003 and phase 2 occurring in 2004-2007. Persons who had undergone a colonoscopy less than 1 year prior to the index colonoscopy, persons with inadequate bowel preparation for the index colonoscopy, and persons with a prior or new diagnosis of colorectal cancer, a familial colorectal cancer syndrome (such as familial adenomatous polyposis), or another colorectal disease were ineligible. Patients diagnosed with adenomas or serrated polyps and persons who were polyp-free at the index colonoscopy (controls) were systematically recruited during both phases of recruitment. Approximately 75% agreed to participate and provided written informed consent. Based on medical records, persons who agreed to participate and those who refused study participation were similar with respect to age, sex, and colorectal polyp status. Study protocols were approved by the institutional review boards of the Group Health Cooperative and the Fred Hutchinson Cancer Research Center (Seattle, Washington). A total of 575 cases and 508 matched were selected for the study. Controls were matched to CRC cases as 1:1 ratio. Matching was done on age_ref, race, and sex. Age_ref was matched on +-5 years. The Women's Health Initiative (WHI): WHI is a long-term national health study that has focused on strategies for preventing heart disease, breast and colorectal cancer, and osteoporotic fractures in postmenopausal women. The original WHI study included 161,808 postmenopausal women enrolled between 1993 and 1998. The Fred Hutchinson Cancer Research Center in Seattle, WA serves as the WHI Clinical Coordinating Center for data collection, management, and analysis of the WHI. The WHI has two major parts: a partial factorial randomized Clinical Trial (CT) and an Observational Study (OS); both were conducted at 40 Clinical Centers nationwide. The CT enrolled 68,132 postmenopausal women between the ages of 50-79 into trials testing three prevention strategies. If eligible, women could choose to enroll in one, two, or all three of the trial components. The components are: Hormone Therapy Trials (HT): This double-blind component examined the effects of combined hormones or estrogen alone on the prevention of coronary heart disease and osteoporotic fractures, and associated risk for breast cancer. Women participating in this component with an intact uterus were randomized to estrogen plus progestin (conjugated equine estrogens [CEE], 0.625 mg/d plus medroxyprogesterone acetate [MPA] 2.5 mg/d] or a matching placebo. Women with prior hysterectomy were randomized to CEE or placebo. Both trials were stopped early, in July 2002 and March 2004, respectively, based on adverse effects. All HT participants continued to be followed without intervention until close-out. Dietary Modification Trial (DM): The Dietary Modification component evaluated the effect of a low-fat and high fruit, vegetable and grain diet on the prevention of breast and colorectal cancers and coronary heart disease. Study participants were randomized to either their usual eating pattern or a low-fat dietary pattern. Calcium/Vitamin D Trial (CaD): This double-blind component began 1 to 2 years after a woman joined one or both of the other clinical trial components. It evaluated the effect of calcium and vitamin D supplementation on the prevention of osteoporotic fractures and colorectal cancer. Women in this component were randomized to calcium (1000 mg/d) and vitamin D (400 IU/d) supplements or a matching placebo. The Observational Study (OS)examines the relationship between lifestyle, environmental, medical and molecular risk factors and specific measures of health or disease outcomes. This component involves tracking the medical history and health habits of 93,676 women not participating in the CT. Recruitment for the observational study was completed in 1998 and participants were followed annually for 8 to 12 years. All centrally confirmed cases of invasive colorectal cancers, or deaths from colorectal cancer were selected as potential cases from September 30, 2015 database. Controls were participants free of colorectal cancer (invasive or in situ) as of September 30, 2015. Potential cases and controls were excluded if they (1) were non-White; (2) had history of colorectal cancers at baseline; (3) lost to follow-up after enrollment; (4) DbGAP ineligible; (5) had <1.25ug of DNA; (6) selected for WHI study M26 Phase I or II; (7) selected for WHI study AS224 and also included in the imputation project. A total of 578 cases and 104,429 controls met the eligibility criteria. Each case was matched with 1 control (1:1) that exactly met the following matching criteria: age (+-5 years), 40 randomization centers (exact), WHI date (+-3 years), CaD date (+-3 years), OS flag (exact), HRT assignments (exact), DM assignments (exact), and CaD assignments (exact). Control selection was done in a time-forward manner, selecting one control for each case from the risk set at the time of the case's event. The matching algorithm was allowed to select the closest match based on a criteria to minimize an overall distance measure (Bergstralh EJ, Kosanke JL. Computerized matching of cases to controls. Technical Report #56, Department of Health Sciences Research, Mayo Clinic, Rochester MN. April 1995). Each matching factor was given the same weight. When exact matches could not be found, the matching criteria were gradually relaxed among unmatched cases and controls until all cases had found matched controls. Using the matching criteria specified above, 559 of the 578 eligible cases found exact matches. The matching criteria was then relaxed to : Age+-5, randomization centers, WHI date +- 3 years, CaD date +- 3 years, OS flag, HRT flag, DM flag, CaD flag. 17 of the remaining 19 unmatched cases found matched controls. By matching on Age+-5, randomization centers, WHI date +- 3 years, CaD date +- 3 years, OS flag, HRT flag, the remaining 2 unmatched cases found their matches.
