Citations 45

Clinical Laboratory Reports in Molecular Pathology

Archives of Pathology & Laboratory Medicine | February 11, 2021 | Volume: 131 | Issue: 6 | Pages: 852-863

10.5858/2007-131-852-clrimp | PMID 17550311

Abstract Context. —Molecular pathology is a rapidly growing area of laboratory medicine in which DNA and RNA are analyzed. The recent introduction of array technology has added another layer of complexity involving massive parallel analysis of multiple genes, transcripts, or proteins. Objective. —As molecular technologies are increasingly implemented in clinical settings, it is important to bring uniformity to the way that test results are reported. Data Sources. —The College of American Pathologists Molecular Pathology Resource Committee members summarize elements that are already common to virtually all molecular pathology reports, as set forth in the College of American Pathologists checklists used in the laboratory accreditation process. Consensus recommendations are proposed to improve report format and content, and areas of controversy are discussed. Resources are cited that promote use of proper gene nomenclature and that describe methods for reporting mutations, translocations, microsatellite instability, and other genetic alterations related to inherited disease, cancer, identity testing, microbiology, and pharmacogenetics. Conclusions. —These resources and recommendations provide a framework for composing patient reports to convey molecular test results and their clinical significance to members of the health care team.
Intake of Dietary Fruit, Vegetables, and Fiber and Risk of Colorectal Cancer According to Molecular Subtypes: A Pooled Analysis of 9 Studies

Cancer Research | August 14, 2020 | Volume: 80 | Issue: 20 | Pages: 4578-4590

10.1158/0008-5472.can-20-0168 | PMID 32816852

Abstract Protective associations of fruits, vegetables, and fiber intake with colorectal cancer risk have been shown in many, but not all epidemiologic studies. One possible reason for study heterogeneity is that dietary factors may have distinct effects by colorectal cancer molecular subtypes. Here, we investigate the association of fruit, vegetables, and fiber intake with four well-established colorectal cancer molecular subtypes separately and in combination. Nine observational studies including 9,592 cases with molecular subtypes for microsatellite instability (MSI), CpG island methylator phenotype (CIMP), and somatic mutations in BRAF and KRAS genes, and 7,869 controls were analyzed. Both case-only logistic regression analyses and polytomous logistic regression analyses (with one control set and multiple case groups) were used. Higher fruit intake was associated with a trend toward decreased risk of BRAF-mutated tumors [OR 4th vs. 1st quartile = 0.82 (95% confidence interval, 0.65–1.04)] but not BRAF-wildtype tumors [1.09 (0.97–1.22); P difference as shown in case-only analysis = 0.02]. This difference was observed in case–control studies and not in cohort studies. Compared with controls, higher fiber intake showed negative association with colorectal cancer risk for cases with microsatellite stable/MSI-low, CIMP-negative, BRAF-wildtype, and KRAS-wildtype tumors (Ptrend range from 0.03 to 3.4e-03), which is consistent with the traditional adenoma-colorectal cancer pathway. These negative associations were stronger compared with MSI-high, CIMP-positive, BRAF-mutated, or KRAS-mutated tumors, but the differences were not statistically significant. These inverse associations for fruit and fiber intake may explain, in part, inconsistent findings between fruit or fiber intake and colorectal cancer risk that have previously been reported. Significance: These analyses by colorectal cancer molecular subtypes potentially explain the inconsistent findings between dietary fruit or fiber intake and overall colorectal cancer risk that have previously been reported.
Postmenopausal Hormone Therapy and Colorectal Cancer Risk by Molecularly Defined Subtypes and Tumor Location

JNCI Cancer Spectrum | May 13, 2020 | Volume: 4 | Issue: 5 | Pages: No page available

10.1093/jncics/pkaa042 | PMID 32923935

AbstractBackgroundPostmenopausal hormone therapy (HT) is associated with a decreased colorectal cancer (CRC) risk. As CRC is a heterogeneous disease, we evaluated whether the association of HT and CRC differs across etiologically relevant, molecularly defined tumor subtypes and tumor location.MethodsWe pooled data on tumor subtypes (microsatellite instability status, CpG island methylator phenotype status, BRAF and KRAS mutations, pathway: adenoma-carcinoma, alternate, serrated), tumor location (proximal colon, distal colon, rectum), and HT use among 8220 postmenopausal women (3898 CRC cases and 4322 controls) from 8 observational studies. We used multinomial logistic regression to estimate odds ratios (OR) and 95% confidence intervals (CIs) for the association of ever vs never HT use with each tumor subtype compared with controls. Models were adjusted for study, age, body mass index, smoking status, and CRC family history. All statistical tests were 2-sided.ResultsAmong postmenopausal women, ever HT use was associated with a 38% reduction in overall CRC risk (OR =0.62, 95% CI = 0.56 to 0.69). This association was similar according to microsatellite instability, CpG island methylator phenotype and BRAF or KRAS status. However, the association was attenuated for tumors arising through the serrated pathway (OR = 0.81, 95% CI = 0.66 to 1.01) compared with the adenoma-carcinoma pathway (OR = 0.63, 95% CI = 0.55 to 0.73; Phet =.04) and alternate pathway (OR = 0.61, 95% CI = 0.51 to 0.72). Additionally, proximal colon tumors had a weaker association (OR = 0.71, 95% CI = 0.62 to 0.80) compared with rectal (OR = 0.54, 95% CI = 0.46 to 0.63) and distal colon (OR = 0.57, 95% CI = 0.49 to 0.66; Phet =.01) tumors.ConclusionsWe observed a strong inverse association between HT use and overall CRC risk, which may predominantly reflect a benefit of HT use for tumors arising through the adenoma-carcinoma and alternate pathways as well as distal colon and rectal tumors.
Functional informed genome‐wide interaction analysis of body mass index, diabetes and colorectal cancer risk

Cancer Medicine | March 24, 2020 | Volume: 9 | Issue: 10 | Pages: 3563-3573

10.1002/cam4.2971 | PMID 32207560

AbstractBackgroundBody mass index (BMI) and diabetes are established risk factors for colorectal cancer (CRC), likely through perturbations in metabolic traits (e.g. insulin resistance and glucose homeostasis). Identification of interactions between variation in genes and these metabolic risk factors may identify novel biologic insights into CRC etiology.MethodsTo improve statistical power and interpretation for gene‐environment interaction (G × E) testing, we tested genetic variants that regulate expression of a gene together for interaction with BMI (kg/m2) and diabetes on CRC risk among 26 017 cases and 20 692 controls. Each variant was weighted based on PrediXcan analysis of gene expression data from colon tissue generated in the Genotype‐Tissue Expression Project for all genes with heritability ≥1%. We used a mixed‐effects model to jointly measure the G × E interaction in a gene by partitioning the interactions into the predicted gene expression levels (fixed effects), and residual G × E effects (random effects). G × BMI analyses were stratified by sex as BMI‐CRC associations differ by sex. We used false discovery rates to account for multiple comparisons and reported all results with FDR <0.2.ResultsAmong 4839 genes tested, genetically predicted expressions of FOXA1 (P = 3.15 × 10−5), PSMC5 (P = 4.51 × 10−4) and CD33 (P = 2.71 × 10−4) modified the association of BMI on CRC risk for men; KIAA0753 (P = 2.29 × 10−5) and SCN1B (P = 2.76 × 10−4) modified the association of BMI on CRC risk for women; and PTPN2 modified the association between diabetes and CRC risk in both sexes (P = 2.31 × 10−5).ConclusionsAggregating G × E interactions and incorporating functional information, we discovered novel genes that may interact with BMI and diabetes on CRC risk.
Abstract 630: Smoking is associated with risks of molecular subtypes of colorectal cancer

Cancer Research | August 7, 2019 | Volume: 79 | Issue: 13_Supplement | Pages: 630-630

10.1158/1538-7445.am2019-630

Abstract Background: Smoking has been associated with colorectal cancer (CRC) risk; but limited evidence has shown the association between smoking and molecular subtypes of CRC. Methods: We analyzed 9,422 CRC cases and 9,950 controls from 10 observational studies. Multinomial logistic regression analysis was performed to assess the association between sex-study-specific quartiles of pack years of smoking and risk of CRC molecular subtypes, using non-smokers as reference group, adjusting for age, sex, and study. Known oncogenic mutations in four somatic colorectal tumor markers were assessed individually and in combination, including BRAF mutations, KRAS mutations, CpG island methylator phenotype (CIMP), and microsatellite instability (MSI) status. Case-only analysis was also performed to estimate heterogeneity in risk of molecular subtypes of CRC. Results: Compared with controls, higher pack years of smoking were statistically significantly associated with increased CRC risk when stratified, individually, by all four markers, and the associations got stronger with higher quartiles pack years (p-trend&lt;0.001). Associations between smoking and CRC risk also differed significantly among molecular subtypes. Compared to nonsmokers, the risk of BRAFmut CRC was 83% higher for smokers within the highest quartile of pack-years (OR=1.83; 95% CI: 1.50, 2.25), and 29% higher for BRAFwt CRC (OR=1.29; 95% CI: 1.17, 1.43; Ratio of ORs (ROR)=1.45; 95% CI: 1.18, 1.17; p=3.45x10-4). Similarly, heavy pack-years of smoking was associated with almost two times higher risk of CIMP-high CRC (OR=1.93; 95% CI: 1.60, 2.31), but only 33% higher risk of CIMP-low/negative CRC (OR=1.33; 95% CI: 1.19, 1.48; ROR=1.49; 95% CI: 1.24, 1.79; p=1.72x10-5). The association between smoking and CRC was also stronger in MSI-high tumors (ORMSI-H=1.65; 95% CI: 1.36, 2.00; ORMSI-L/MSS=1.37; 95% CI: 1.23, 1.52; ROR=1.22; 95% CI: 1.00, 1.48; p=0.046). In contrast, the association between smoking and CRC risk was stronger for KRASwt (OR=1.43; 95% CI: 1.27, 1.60), than KRASmut tumors (OR=1.18; 95% CI: 1.02, 1.37; ROR=0.83; 95% CI: 0.71, 0.97; p =0.016). When combining tumor markers, smoking was found to be significantly associated with higher risk of colorectal tumors from the serrated pathway. Conclusion: In this largest study with a total of 19,372 subjects, we found that heavier pack years of smoking was associated with increased risk of all CRC molecular subtypes. Smokers with heavier pack-years of smoking had particularly higher risk of CRC subtypes with BRAF mutation and CIMP-high, suggesting smoking may be particularly involved in the development of these subtypes of colorectal tumor. Citation Format: Xiaoliang Wang, Efrat Amitay, Barbara L. Banbury, Hermann Brenner, Daniel D. Buchanan, Peter T. Campbell, Jenny Chang-Claude, Steven J. Gallinger, Graham G. Giles, Tabitha A. Harrison, John L. Hopper, Mark A. Jenkins, Yi Lin, Reiko Nishihara, Polly A. Newcomb, Shuji Ogino, Lori C. Sakoda, Robert E. Schoen, Martha L. Slattery, Steven N. Thibodeau, Bethany Van Guelpen, Michael O. Woods, Li Hsu, Michael Hoffmeister, Ulrike Peters. Smoking is associated with risks of molecular subtypes of colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 630.
DNA repair and cancer in colon and rectum: Novel players in genetic susceptibility

International Journal of Cancer | June 18, 2019 | Volume: 146 | Issue: 2 | Pages: 363-372

10.1002/ijc.32516 | PMID 31209889

Interindividual differences in DNA repair systems may play a role in modulating the individual risk of developing colorectal cancer. To better ascertain the role of DNA repair gene polymorphisms on colon and rectal cancer risk individually, we evaluated 15,419 single nucleotide polymorphisms (SNPs) within 185 DNA repair genes using GWAS data from the Colon Cancer Family Registry (CCFR) and the Genetics and Epidemiology of Colorectal Cancer Consortium (GECCO), which included 8,178 colon cancer, 2,936 rectum cancer cases and 14,659 controls. Rs1800734 (in MLH1 gene) was associated with colon cancer risk (p‐value = 3.5 × 10−6) and rs2189517 (in RAD51B) with rectal cancer risk (p‐value = 5.7 × 10−6). The results had statistical significance close to the Bonferroni corrected p‐value of 5.8 × 10−6. Ninety‐four SNPs were significantly associated with colorectal cancer risk after Binomial Sequential Goodness of Fit (BSGoF) procedure and confirmed the relevance of DNA mismatch repair (MMR) and homologous recombination pathways for colon and rectum cancer, respectively. Defects in MMR genes are known to be crucial for familial form of colorectal cancer but our findings suggest that specific genetic variations in MLH1 are important also in the individual predisposition to sporadic colon cancer. Other SNPs associated with the risk of colon cancer (e.g., rs16906252 in MGMT) were found to affect mRNA expression levels in colon transverse and therefore working as possible cis‐eQTL suggesting possible mechanisms of carcinogenesis.
Abstract 229: Genome-wide association study by colorectal carcinoma subtype

Cancer Research | August 17, 2018 | Volume: 78 | Issue: 13_Supplement | Pages: 229-229

10.1158/1538-7445.am2018-229

Abstract Over 50 genetic variants have been associated with colorectal cancer (CRC) risk through genome-wide association studies (GWAS), yet these variants represent only a fraction of the total estimated heritability. CRC is a heterogenous disease with diverse tumor etiology. Assessing genetic risk in molecular subtypes may help to identify novel loci and characterize genetic risk among tumor subtypes. We used microsatellite instability (MSI), an established CRC classifier with etiological and therapeutic relevance, to define CRC subtypes for GWAS analyses. We conducted a case-case analysis to estimate odds ratios (OR) and 95% confidence intervals (CI) for association of genome-wide variants with microsatellite stable (MSS) versus unstable (MSI) carcinomas. We ran an inverse-variance weighted fixed-effects meta-analysis across GWAS in a discovery set of 4,163 population-based CRC cases with harmonized microsatellite instability (MSI) marker and imputed genotype data. For each analysis, we used log-additive logistic regression, adjusting for age, sex, and principal components to account for population substructure. We then followed up with replication of 102 SNPs that reached p-values less than 5x10-6 in 1,698 cases. A total of 845 (20.3%) cancer cases were microsatellite unstable in the discovery population and 174 (10.2%) were unstable in the replication population. No variants reached the genome-wide significance level of 5x10-8 in the discovery set. However, we identified two variants that reached a Bonferroni corrected p-value of 4.0x10-4 in the replication set. This included one variant in MLH1 (Replication: OR=1.74, 95% CI=1.53-1.98, p=1.63x10-5; Discovery+Replication: OR=1.45, 95% CI=1.37-1.54, p=9.76x10-11) and one variant in LOC105377645 (Replication: OR=1.70, 95% CI=1.49-1.94, p=5.13x10-5; Discovery+Replication: OR=1.45, 95% CI=1.37-1.54, p=9.76 x 10-11). The MLH1 gene is a DNA mismatch repair gene implicated in Lynch Syndrome, the hallmark of which is microsatellite instability. This is the first genome-wide scan to identify a common variant in MLH1 that is associated with CRC. This variant (minor allele frequency, MAF = 23% in this all European ancestry population) is located in the 5'-untranslated region of MLH1 and is thought to act as a long-range regulator of DCLK3, a potential tumor driver gene. The second variant, located in LOC105377645 with an MAF of 22%, is in an uncharacterized region of the genome and has not previously been implicated in cancer development. These findings suggest that accounting for molecular heterogeneity is important for discovery and characterization of genetic variants associated with CRC risk. We plan to run polytomous regression analyses, increase our sample size, and further investigate CRC subtypes by CIMP, BRAF mutation, KRAS mutation status. Citation Format: Tabitha A. Harrison, Yiwen Lu, Chenjie Zeng, Flora Qu, Kristin Anderson, Hermann Brenner, Daniel D. Buchanan, Peter T. Campbell, Andrew T. Chan, Jenny Chang-Claude, Graham G. Giles, Bethany Van Guelpen, Michael Hoffmeister, Mark A. Jenkins, Noralane M. Lindor, Roger L. Milne, Polly A. Newcomb, Reiko Nishihara, Michael O. Woods, Shuji Ogino, John D. Potter, Martha L. Slattery, Wei Sun, Stephen N. Thibodeau, Li Hsu, Ulrike Peters. Genome-wide association study by colorectal carcinoma subtype [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 229.
Dietary Fat Intake after Colon Cancer Diagnosis in Relation to Cancer Recurrence and Survival: CALGB 89803 (Alliance)

Cancer Epidemiology, Biomarkers & Prevention | July 23, 2018 | Volume: 27 | Issue: 10 | Pages: 1227-1230

10.1158/1055-9965.epi-18-0487 | PMID 30038051

Abstract Background: Higher intake of long-chain ω-3 polyunsaturated fatty acids and nuts, rich plant sources of unsaturated fats, after colon cancer diagnosis are associated with improved survival. It is not known whether the amount or the distribution of other types of fat is associated with survival after colon cancer. Methods: We prospectively examined postdiagnostic total, animal, and vegetable fats, as well as the saturated, monounsaturated, polyunsaturated, and trans fat in relation to disease-free survival among 1,011 patients with stage III colon cancer. Patients were enrolled between 1999 and 2001 at the onset of adjuvant chemotherapy and followed for recurrence or death through 2009. Results: During median follow-up of 7 years, we observed 305 deaths and 81 recurrences (total events: 386). Neither total nor any specific type of dietary fat examined was statistically significantly associated with risk of cancer recurrence or death from any cause (disease-free survival) after stage III colon cancer. Conclusions: The amount and type (animal, vegetable, saturated, monounsaturated, polyunsaturated, and trans) of dietary fat consumed after colon cancer does not appear to be substantially associated with risk of recurrence or survival. Impact: Neither total nor major types (animal, vegetable, saturated, monounsaturated, polyunsaturated, and trans) of dietary fat consumed after colon cancer was associated with cancer recurrence or survival. Cancer Epidemiol Biomarkers Prev; 27(10); 1227–30. ©2018 AACR.
Abstract 1286: Targeted deep sequencing of colorectal tumor tissues to study associations of tumor subtypes with germline genetic, lifestyle, and environmental risk factors

Cancer Research | July 31, 2017 | Volume: 77 | Issue: 13_Supplement | Pages: 1286-1286

10.1158/1538-7445.am2017-1286

Abstract The Genetics and Epidemiology of Colorectal Cancer Consortium (GECCO) in collaboration with the Colorectal Cancer Family Registry (CCFR) aims to identify genetic variants and environmental risk factors that impact colorectal cancer (CRC). Over 30 studies from North America, Europe, and Australia participate in GECCO. These studies have collected clinical, epidemiological, and survival data, as well as blood and tumor biospecimens, for over 80,000 CRC cases and controls. The current study aims to conduct targeted deep sequencing of tumors and matching normal DNA to identify recurrent and novel somatic and germline variants in 4,200 CRC cases. To achieve this goal, an AmpliSeq targeted sequencing panel of 1.12 Mbp was constructed to sequence the coding regions of 190 significantly mutated genes identified from whole exome sequencing datasets generated by the Nurses’ Health Study and Health Professional’s Follow-up Study, and The Cancer Genome Atlas. The panel also covers coding regions of 15 genes with germline high penetrance mutations in CRC, 54 regions to detect CRC-related copy number alterations (CNAs), and microsatellite and homopolymer repeat regions to identify defective DNA mismatch repair. Primers were also included to detect Fusobacterium nucleatum DNA in tumor biopsies, as F. nucleatum is thought to promote CRC carcinogenesis. Sequencing of the DNA libraries on Illumina HiSeq 2500 produced a mean coverage of greater than 500X for tumor DNA and 100X for normal DNA, with &gt;85% of the bases covered at the target at 50x. So far, targeted sequencing of &gt;1,500 DNA samples from CRC tumors and normal tissues has identified recurrent and novel somatic mutations, germline genetic variants, and hypermutation status of the tumors due to defective DNA mismatch repair or pathogenic mutations in the POLE gene. Targeted sequencing has also allowed quantification of the F. nucleatum DNA in tumor biopsies; the results were validated by a multiplex QPCR assay. At the AACR annual meeting, we will present targeted sequencing results generated from the first two GECCO-participating studies (n=1,300 cases). These data will be valuable for future association testing of somatic mutations, CNAs, hypermutation status, and F. nucleatum with germline genetic variants, lifestyle, and environmental risk factors and survival. This large study will allow development of better strategies for diagnosis, treatment, and prevention of CRC. Citation Format: Syed H. Zaidi, Wei Sun, Jeroen Huyghe, Catherine S. Grasso, Quang Trinh, Charles Connolly, Amy French, Jasmine Mu, Marios Giannakis, Eve Shinbrot, Ivan Borozan, Michael J. Quist, Hermann Brenner, Daniel Buchanan, Peter Campbell, Andrew Chan, Jenny Chang-Claude, Vincent Ferretti, Charles Fuchs, Andrea Gsur, Marc Gunter, Tabitha Harrison, Michael Hoffmeister, Wen-Yi Huang, Paul Krzyzanowski, Stephen Lee, Mathieu Lemire, Jessica Miller, Danielle Pasternack, Cherie Teney, Elaine Mardis, Polly Newcomb, Lincoln Stein, Lee Timms, David Wheeler, Christina Yung, Niha Zubair, Levi Garraway, Shuji Ogino, Li Hsu, Steven Gallinger, Stephen Thibodeau, Thomas Hudson, Ulrike Peters. Targeted deep sequencing of colorectal tumor tissues to study associations of tumor subtypes with germline genetic, lifestyle, and environmental risk factors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1286. doi:10.1158/1538-7445.AM2017-1286
Genetic Variants in Epigenetic Pathways and Risks of Multiple Cancers in the GAME-ON Consortium

Cancer Epidemiology, Biomarkers & Prevention | January 23, 2017 | Volume: 26 | Issue: 6 | Pages: 816-825

10.1158/1055-9965.epi-16-0728 | PMID 28115406

Abstract Background: Epigenetic disturbances are crucial in cancer initiation, potentially with pleiotropic effects, and may be influenced by the genetic background. Methods: In a subsets (ASSET) meta-analytic approach, we investigated associations of genetic variants related to epigenetic mechanisms with risks of breast, lung, colorectal, ovarian and prostate carcinomas using 51,724 cases and 52,001 controls. False discovery rate–corrected P values (q values &lt; 0.05) were considered statistically significant. Results: Among 162,887 imputed or genotyped variants in 555 candidate genes, SNPs in eight genes were associated with risk of more than one cancer type. For example, variants in BABAM1 were confirmed as a susceptibility locus for squamous cell lung, overall breast, estrogen receptor (ER)–negative breast, and overall prostate, and overall serous ovarian cancer; the most significant variant was rs4808076 [OR = 1.14; 95% confidence interval (CI) = 1.10–1.19; q = 6.87 × 10−5]. DPF1 rs12611084 was inversely associated with ER-negative breast, endometrioid ovarian, and overall and aggressive prostate cancer risk (OR = 0.93; 95% CI = 0.91–0.96; q = 0.005). Variants in L3MBTL3 were associated with colorectal, overall breast, ER-negative breast, clear cell ovarian, and overall and aggressive prostate cancer risk (e.g., rs9388766: OR = 1.06; 95% CI = 1.03–1.08; q = 0.02). Variants in TET2 were significantly associated with overall breast, overall prostate, overall ovarian, and endometrioid ovarian cancer risk, with rs62331150 showing bidirectional effects. Analyses of subpathways did not reveal gene subsets that contributed disproportionately to susceptibility. Conclusions: Functional and correlative studies are now needed to elucidate the potential links between germline genotype, epigenetic function, and cancer etiology. Impact: This approach provides novel insight into possible pleiotropic effects of genes involved in epigenetic processes. Cancer Epidemiol Biomarkers Prev; 26(6); 816–25. ©2017 AACR.