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BACKGROUND: Colorectal cancer is the third most common cancer in the world. In this study, we assessed the long-term survival characteristics and prognostic associations and potential time-varying effects of clinico-demographic variables and two molecular markers (microsatellite instability (MSI) and BRAF Val600Glu mutation) in a population-based patient cohort followed up to ~ 19 years. METHODS: The patient cohort included 738 incident cases diagnosed between 1999 and 2003. Cox models were used to analyze the association between the variables and a set of survival outcome measures (overall survival (OS), disease-specific survival (DSS), recurrence-free survival (RFS), metastasis-free survival (MFS), recurrence/metastasis-free survival (RMFS), and event-free survival (EFS)). Cox proportional hazard (PH) assumption was tested for all variables, and Cox models with time-varying effects were used if any departure from the PH assumption was detected. RESULTS: During the follow-up, ~ 61% patients died from any cause, ~ 26% died from colorectal cancer, and ~ 10% and ~ 20% experienced recurrences and distant metastases, respectively. Stage IV disease and post-diagnostic recurrence or metastasis were strongly linked to risk of death from colorectal cancer. If a patient had survived the first 6 years without any disease-related event (i.e., recurrence, metastasis, or death from colorectal cancer), their risks became very minimal after this time period. Distinct sets of markers were associated with different outcome measures. In some cases, the effects by variables were constant throughout the follow-up. For example, MSI-high tumor phenotype and older age at diagnosis predicted longer MFS times consistently over the follow-up. However, in some other cases, the effects of the variables varied with time. For example, adjuvant radiotherapy treatment was associated with increased risk of metastasis in patients who received this treatment after 5.5 years post-diagnosis, but not before that. CONCLUSIONS: This study describes the long-term survival characteristics of a prospective cohort of colorectal cancer patients, relationships between baseline variables and a detailed set of patient outcomes over a long time, and time-varying effects of a group of variables. The results presented advance our understanding of the long-term prognostic characteristics in colorectal cancer and are expected to inspire future studies and clinical care strategies.
Subject(s)
Cancer Survivors/statistics & numerical data , Colorectal Neoplasms/mortality , Adult , Aged , Cohort Studies , Colorectal Neoplasms/epidemiology , Colorectal Neoplasms/genetics , Disease-Free Survival , Female , Follow-Up Studies , Humans , Male , Microsatellite Instability , Middle Aged , Mutation, Missense , Neoplasm Recurrence, Local/epidemiology , Neoplasm Recurrence, Local/genetics , Phenotype , Prognosis , Proto-Oncogene Proteins B-raf/genetics , Survival Analysis , Time Factors , Young AdultABSTRACT
BACKGROUND: Differentiating between cancer patients who will experience metastasis within a short time and who will be long-term survivors without metastasis is a critical aim in healthcare. The microsatellite instability (MSI)-high tumor phenotype is such a differentiator in colorectal cancer, as patients with these tumors are unlikely to experience metastasis. Our aim in this study was to determine if germline genetic variations could further differentiate colorectal cancer patients based on the long-term risk and timing of metastasis. METHODS: The patient cohort consisted of 379 stage I-III Caucasian colorectal cancer patients with microsatellite stable or MSI-low tumors. We performed univariable analysis on 810,622 common single nucleotide polymorphisms (SNPs) under different genetic models. Depending on the long-term metastasis-free survival probability estimates, we applied a mixture cure model, Cox proportional hazards regression model, or log-rank test. For SNPs reaching Bonferroni-corrected significance (p < 6.2 × 10- 8) having valid genetic models, multivariable analysis adjusting for significant baseline characteristics was conducted. RESULTS: After adjusting for significant baseline characteristics, specific genotypes of ten polymorphisms were significantly associated with time-to-metastasis. These polymorphisms are three intergenic SNPs, rs5749032 (p = 1.28 × 10- 10), rs2327990 (p = 9.59 × 10- 10), rs1145724 (p = 3 × 10- 8), and seven SNPs within the non-coding sequences of three genes: FHIT (p = 2.59 × 10- 9), EPHB1 (p = 8.23 × 10- 9), and MIR7515 (p = 4.87 × 10- 8). CONCLUSIONS: Our results suggest novel associations of specific genotypes of SNPs with early metastasis in Caucasian colorectal cancer patients. These associations, once replicated in other patient cohorts, could assist in the development of personalized treatment strategies for colorectal cancer patients.
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BACKGROUND: The rs2282679 A>C polymorphism in the vitamin D binding protein gene is associated with lower circulating levels of vitamin D. We investigated associations of this SNP with colorectal cancer (CRC) risk and survival and whether the associations vary by dietary vitamin D intake and tumor molecular phenotype. METHODS: A population-based case-control study identified 637 incident CRC cases (including 489 participants with follow-up data on mortality end-points) and 489 matched controls. Germline DNA samples were genotyped with the Illumina Omni-Quad 1 Million chip in cases and the Affymetrix Axiom® myDesign™ Array in controls. Logistic regression examined the association between the rs2282679 polymorphism and CRC risk with inclusion of potential confounders. Kaplan-Meier curves and multivariable Cox models assessed the polymorphism relative to overall survival (OS) and disease-free survival (DFS). RESULTS: The rs2282679 polymorphism was not associated with overall CRC risk; there was evidence, however, of effect modification by total vitamin D intake (Pinteraction = 0.019). Survival analyses showed that the C allele was correlated with poor DFS (per-allele HR, 1.36; 95%CI, 1.05-1.77). The association of rs2282679 on DFS was limited to BRAF wild-type tumors (HR, 1.58; 95%CI, 1.12-2.23). For OS, the C allele was associated with higher all-cause mortality among patients with higher levels of dietary vitamin D (HR, 2.11; 95%CI, 1.29-3.74), calcium (HR, 1.93; 95%CI, 1.08-3.46), milk (HR, 2.36; 95%CI, 1.26-4.44), and total dairy product intakes (HR, 2.03; 95%CI, 1.11-3.72). CONCLUSION: The rs2282679 SNP was not associated with overall CRC risk, but may be associated with survival after cancer diagnosis. The association of this SNP on survival among CRC patients may differ according to dietary vitamin D and calcium intakes and according to tumor BRAF mutation status.
Subject(s)
Colorectal Neoplasms/genetics , Genetic Predisposition to Disease/genetics , Polymorphism, Single Nucleotide , Vitamin D-Binding Protein/genetics , Aged , Case-Control Studies , Diet , Female , Gene Frequency , Genotype , Humans , Kaplan-Meier Estimate , Male , Middle Aged , Risk Factors , Vitamin D/administration & dosage , Vitamins/administration & dosageABSTRACT
BACKGROUND: Increased serum levels of vitamin D and calcium have been associated with lower risks of colorectal cancer (CRC) incidence and mortality. These inverse associations may be mediated by the vitamin D receptor (VDR) and the calcium-sensing receptor (CASR). We investigated genetic variants in VDR and CASR for their relevance to CRC prognosis. METHODS: A population-based cohort of 531 CRC patients diagnosed from 1999 to 2003 in Newfoundland and Labrador, Canada, was followed for mortality and cancer recurrence until April 2010. Germline DNA samples were genotyped with the Illumina Omni-Quad 1 Million chip. Multivariate Cox models assessed 41 tag single-nucleotide polymorphisms and relative haplotypes on VDR and CASR in relation to all-cause mortality (overall survival, OS) and disease-free survival (DFS). RESULTS: Gene-level associations were observed between VDR and the DFS of rectal cancer patients (P=0.037) as well as between CASR and the OS of colon cancer patients (P=0.014). Haplotype analysis within linkage blocks of CASR revealed the G-G-G-G-G-A-C haplotype (rs10222633-rs10934578-rs3804592-rs17250717-A986S-R990G-rs1802757) to be associated with a decreased OS of colon cancer (HR, 3.15; 95% CI, 1.66-5.96). Potential interactions were seen among prediagnostic dietary calcium intake with the CASR R990G (Pint=0.040) and the CASR G-T-G-G-G-G-C haplotype for rs10222633-rs10934578-rs3804592-rs17250717-A986S-R990G-rs1802757 (Pint=0.017), with decreased OS time associated with these variants limited to patients consuming dietary calcium below the median, although the stratified results were not statistically significant after correction for multiple testing. CONCLUSIONS: Polymorphic variations in VDR and CASR may be associated with survival after a diagnosis of CRC.
Subject(s)
Colonic Neoplasms/genetics , Colonic Neoplasms/mortality , Genetic Variation , Neoplasm Recurrence, Local , Receptors, Calcitriol/genetics , Receptors, Calcium-Sensing/genetics , Rectal Neoplasms/genetics , Rectal Neoplasms/mortality , Diet/adverse effects , Disease-Free Survival , Female , Haplotypes , Humans , Male , Middle Aged , Newfoundland and Labrador , Oligonucleotide Array Sequence Analysis , Polymorphism, Single Nucleotide , Proportional Hazards ModelsABSTRACT
Polymorphisms in the vascular endothelial growth factor (VEGF)/angiogenesis pathway have been implicated previously in cancer risk, prognosis and response to therapy including in esophageal adenocarcinoma. Prior esophageal adenocarcinoma studies focused on using candidate polymorphisms, limiting the discovery of novel polymorphisms. Here, we applied the tagSNP (single nucleotide polymorphism) approach to identify new VEGF pathway polymorphisms associated with esophageal adenocarcinoma prognosis and validated them in an independent cohort of esophageal adenocarcinoma patients. In 231 esophageal adenocarcinoma patients of all stages/treatment plans, 58 genetic polymorphisms (18 KDR, 7 VEGFA and 33 FLT1) selected through tagging and assessment of predicted function were genotyped. Cox-proportional hazard models adjusted for important socio-demographic and clinico-pathological factors were applied to assess the association of genetic polymorphisms with overall survival (OS) and progression-free survival (PFS). Significantly associated polymorphisms were then validated in an independent cohort of 137 esophageal adenocarcinoma patients. Among the 231 discovery cohort patients, 86% were male, median diagnosis age was 64 years, 34% were metastatic at diagnosis and median OS and PFS were 20 and 12 months, respectively. KDR rs17709898 was found significantly associated with PFS (adjusted hazard ratio, aHR = 0.69, 95% confidence interval (CI): 0.53-0.90; P = 5.9E-3). FLT1 rs3794405 and rs678714 were significantly associated with OS (aHR = 1.44, 95% CI: 1.04-1.99; P = 0.03 and aHR = 1.50, 95% CI: 1.01-2.24; P = 0.045, respectively). No VEGFA polymorphisms were found significantly associated with either outcome. Upon validation, FLT1 rs3794405 remained strongly associated with OS (aHR = 1.59, 95% CI: 1.04-2.44; P = 0.03). FLT1 rs3794405 is significantly associated with OS in esophageal adenocarcinoma, whereby each variant allele confers a 45-60% increased risk of mortality. Validation and evaluation of this association in other cancer sites are warranted.
Subject(s)
Adenocarcinoma/genetics , Esophageal Neoplasms/genetics , Neovascularization, Pathologic/genetics , Vascular Endothelial Growth Factor A/genetics , Vascular Endothelial Growth Factor Receptor-1/genetics , Vascular Endothelial Growth Factor Receptor-2/genetics , Adenocarcinoma/mortality , Adult , Aged , Aged, 80 and over , Disease-Free Survival , Esophageal Neoplasms/mortality , Female , Humans , Male , Middle Aged , Polymorphism, Single Nucleotide/genetics , Prospective Studies , Surveys and QuestionnairesABSTRACT
BACKGROUND/AIMS: Gene network analysis can be a very valuable approach for elucidating complex dependence between functional SNPs in a candidate genetic pathway and for assessing their association with a disease of interest. Even when the number of SNPs evaluated is relatively small (<20), the number of potential gene networks induced by the SNPs can be very large and the contingency tables representing their joint distribution very sparse. METHODS: In this paper, we propose a Bayesian model determination for gene network analysis using decomposable discrete graphical models combined with Reversible Jump Markov chain Monte Carlo. We show the application of this approach in a study of 13 SNPs in the DNA repair pathway and their association with breast cancer from a case-control study conducted in Ontario, Canada. RESULTS: The strength of associations among the SNPs and between the SNPs and the disease status is evaluated by computing the posterior probability of any pair of variables. The corresponding gene network is reconstructed by retaining pair-wise associations with the highest posterior probabilities. In our real data analysis, we found evidence for a particular association between one SNP in the gene POLL and the disease status and also several interesting patterns of association between the SNPs themselves. CONCLUSION: This general statistical framework could serve as a basis for prioritizing genes and SNPs that play a major role in breast cancer etiology and to better understand their complex interactions in a specific genetic pathway.
Subject(s)
Bayes Theorem , Breast Neoplasms/genetics , Gene Regulatory Networks , Models, Statistical , Breast Neoplasms/epidemiology , Case-Control Studies , DNA Repair/genetics , Humans , Ontario/epidemiology , Polymorphism, Single NucleotideABSTRACT
Analysis of genetic polymorphisms may help identify putative prognostic markers and determine the biological basis of variable prognosis in patients. However, in contrast to other variables commonly used in the prognostic studies, there are special considerations when studying genetic polymorphisms. For example, variable inheritance patterns (recessive, dominant, codominant, and additive genetic models) need to be explored to identify the specific genotypes associated with the outcome. In addition, several characteristics of genetic polymorphisms, such as their minor allele frequency and linkage disequilibrium among multiple polymorphisms, and the population substructure of the cohort investigated need to be accounted for in the analyses. In addition, in cancer research due to the genomic differences between the tumor and non-tumor DNA, differences in the genetic information obtained using these tissues need to be carefully assessed in prognostic studies. In this article, we review these and other considerations specific to genetic polymorphism by focusing on genetic prognostic studies in cancer.
Subject(s)
Genetic Predisposition to Disease/genetics , Neoplasms/genetics , Polymorphism, Genetic/genetics , Translational Research, Biomedical/methods , Animals , Gene Frequency/genetics , Genetic Linkage/genetics , Genetic Predisposition to Disease/epidemiology , Humans , Neoplasms/diagnosis , Neoplasms/epidemiology , Prognosis , Translational Research, Biomedical/trendsABSTRACT
Background: Interactions among genetic variants are rarely studied but may explain a part of the variability in patient outcomes. Objectives: In this study, we aimed to identify 1 to 3 way interactions among SNPs from five Wnt protein interaction networks that predict the 5-year recurrence risk in a cohort of stage I-III colorectal cancer patients. Methods: 423 patients recruited to the Newfoundland Familial Colorectal Cancer Registry were included. Five Wnt family member proteins (Wnt1, Wnt2, Wnt5a, Wnt5b, and Wnt11) were selected. The BioGRID database was used to identify the proteins interacting with each of these proteins. Genotypes of the SNPs located in the interaction network genes were retrieved from a genome-wide SNP genotype data previously obtained in the patient cohort. The GMDR 0.9 program was utilized to examine 1-, 2-, and 3-SNP interactions using a 5-fold cross validation step. Top GMDR 0.9 models were assessed by permutation testing and, if significant, prognostic associations were verified by multivariable logistic regression models. Results: GMDR 0.9 has identified novel 1, 2, and 3-way SNP interactions associated with 5-year recurrence risk in colorectal cancer. Nine of these interactions were multi loci interactions (2-way or 3-way). Identified interaction models were able to distinguish patients based on their 5-year recurrence-free status in multivariable regression models. The significance of interactions was the highest in the 3-SNP models. Several of the identified SNPs were eQTLs, indicating potential biological roles of the genes they were associated with in colorectal cancer recurrence. Conclusions: We identified novel interacting genetic variants that associate with 5-year recurrence risk in colorectal cancer. A significant portion of the genes identified were previously linked to colorectal cancer pathogenesis or progression. These variants and genes are of interest for future functional and prognostic studies. Our results provide further evidence for the utility of GMDR models in identifying novel prognostic biomarkers and the biological importance of the Wnt pathways in colorectal cancer.
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BACKGROUND: Secondary primary cancers (SPCs), a major cause of morbidity and mortality in head and neck cancers (HNCs), are commonly associated with field cancerization. We comprehensively evaluated 23 germline sequence variants (from published literature) in 17 genes from 7 biological pathways associated with the HNC survival. Because cancer prognosis correlates with disease aggressiveness, the factors that determine aggressive disease may influence field cancerization process to favor SPC development. We thus hypothesized that the same sequence variants associated with HNC survival can also be associated with SPC. METHODS: Germline DNA from 531 stage I-II radiation-treated HNC patients (originally recruited for an alpha-tocopherol/beta-carotene placebo-controlled secondary prevention clinical trial) were genotyped, and analyzed using Cox proportional hazards models, stratified by treatment arm, adjusting for clinical prognostic factors. RESULTS: The majority of SPCs were of lung and HNCs. Median follow-up time was 5 years. SPCs were diagnosed in 21% of patients. The 5-year SPC-free survival was 79%. All but 1 evaluated sequence variant were not associated with SPC. There was a strong association of the DNA (cytosine-5-)-methyltransferase 3 beta (DNMT3B) sequence variant, DNMT3B:C149T (rs2424913) with SPC: the adjusted hazard ratio (aHR) for TT versus CC was 2.23 (1.32-3.78; P = .003), whereas each variant T allele was associated with an aHR of 1.49 (1.15-1.95; P = .003). CONCLUSIONS: A functional sequence variant in DNMT3B is associated with the development of SPCs in HNC early stage patients treated with radiation. Aberrant DNA methylation may be an important modulator of SPC development in at-risk individuals with HNCs.
Subject(s)
DNA (Cytosine-5-)-Methyltransferases/genetics , Head and Neck Neoplasms/genetics , Neoplasms, Second Primary/genetics , Adult , Aged , Aged, 80 and over , DNA Methylation , Female , Genotype , Head and Neck Neoplasms/mortality , Head and Neck Neoplasms/pathology , Head and Neck Neoplasms/radiotherapy , Humans , Male , Middle Aged , Neoplasm Staging , Polymorphism, Single Nucleotide , Proportional Hazards Models , DNA Methyltransferase 3BABSTRACT
INTRODUCTION: Angiogenesis causes local growth, aggressiveness and metastasis in solid tumors, and thus, is almost always associated with poor prognosis and survival in cancer patients. Because of this clinical importance, several chemotherapeutic agents targeting angiogenesis have also been developed. Genes and genetic variations in angiogenesis/VEGF pathway thus may be correlated with clinical outcome in cancer patients. MATERIAL AND METHODS: Here, we describe a manually curated public database, dbANGIO, which posts the results of studies testing the possible correlation of genetic variations (polymorphisms and mutations) from the angiogenesis/VEGF pathway with demographic features, clinicopathological features, treatment response and toxicity, and prognosis and survival-related endpoints in human cancers. The scientific findings are retrieved from PUBMED and posted in the dbANGIO website in a summarized form. RESULTS AND CONCLUSION: As of September 2011, dbANGIO includes 362 entries from 83 research articles encompassing 154 unique genetic variations from 39 genes investigated in several solid and hematological cancers. By curating the literature findings and making them freely available to researchers, dbANGIO will expedite the research on genetic factors from the angiogenesis pathway and will assist in their utility in clinical management of cancer patients. dbANGIO is freely available for non-profit institutions at http://www.med.mun.ca/angio.
Subject(s)
Databases, Genetic , Neoplasms/genetics , Neovascularization, Pathologic/genetics , Signal Transduction/genetics , Vascular Endothelial Growth Factors/genetics , Genetic Markers , Humans , Neoplasms/blood supply , PrognosisABSTRACT
Background: SNP interactions may explain the variable outcome risk among colorectal cancer patients. Examining SNP interactions is challenging, especially with large datasets. Multifactor Dimensionality Reduction (MDR)-based programs may address this problem. Objectives: 1) To compare two MDR-based programs for their utility; and 2) to apply these programs to sets of MMP and VEGF-family gene SNPs in order to examine their interactions in relation to colorectal cancer survival outcomes. Methods: This study applied two data reduction methods, Cox-MDR and GMDR 0.9, to study one to three way SNP interactions. Both programs were run using a 5-fold cross validation step and the top models were verified by permutation testing. Prognostic associations of the SNP interactions were verified using multivariable regression methods. Eight datasets, including SNPs from MMP family genes (n = 201) and seven sets of VEGF-family interaction networks (n = 1,517 SNPs) were examined. Results: â¼90 million potential interactions were examined. Analyses in the MMP and VEGF gene family datasets found several novel 1- to 3-way SNP interactions. These interactions were able to distinguish between the patients with different outcome risks (regression p-values 0.03-2.2E-09). The strongest association was detected for a 3-way interaction including CHRM3.rs665159_EPN1.rs6509955_PTGER3.rs1327460 variants. Conclusion: Our work demonstrates the utility of data reduction methods while identifying potential prognostic markers in colorectal cancer.
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BACKGROUND: Partnering with patients and family members affected by cancer is essential for meaningful research, public engagement and outreach, and advocacy activities. OBJECTIVE: Our objective was to create a public interest group through an academic-community partnership focused on cancer research and public engagement. METHODS: A purposeful recruitment process was implemented to ensure a diverse and inclusive group. The group meets virtually and communicates by email. The group's activities focus on identifying the needs, priorities, and interests of cancer-affected individuals in the province; consultations; and designing research projects and public outreach activities together. Comprehensive meeting minutes are kept and used to distill discussion points. The work of the group is disseminated through a variety of channels. RESULTS: The public interest group includes 12 cancer patient and family member representatives, in addition to researchers. Discussions by the interest group identified key themes related to: (1) equity issues and regional disparity in provincial oncocare; (2) information needs; (3) need for patient empowerment and public understanding; and (4) family member and partner needs and experiences. To date, the group has co-designed a cancer research proposal and a public engagement/outreach activity. The group also provides consultations on cancer-related projects/public engagement activities and members act as patient partners in specific research and public engagement proposals. The group evolves over time, and increasingly advocates on behalf of cancer patients and families. Retention and satisfaction of the public partners with group activities have been high. The group's work and findings are disseminated to the Provincial Cancer Care Program, as well as to public and scientific stakeholders through local media, academic conferences and presentations, and a dedicated website. CONCLUSION: Public Interest Group on Cancer Research represents a highly successful patient-researcher partnership in oncology. It designs meaningful and patient-oriented studies and outreach activities in cancer. It also elevates and widely supports cancer patient and family voice.
Cancer patients and their family members have unique and lived experience with the condition. Therefore, collaborating with them is important in cancer science. We aimed to create such a collaboration in Newfoundland and Labrador, Canada. In 2021, we successfully formed our diverse collaborative group. Currently, our group includes 12 public representatives. We meet online and discuss matters important to members. We also design studies and events together. Our discussions have identified four topics that need further research and policy changes such as information needs and unique needs of caregivers and family members. Our activities expand over time. For example, lately we started to advocate for other cancer patients and families. In conclusion, we formed a successful cancer patient, family member, and researcher collaborative group. Our work informs the public, healthcare systems, and scientists on important cancer related matters.
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Monogenic, high penetrance syndromes, conferring an increased risk of malignancies in multiple organs, are important contributors to the hereditary burden of cancer. Early detection and risk reduction strategies in patients with a cancer predisposition syndrome can save their lives. However, despite evidence supporting the benefits of early detection and risk reduction strategies, most Canadian jurisdictions have not implemented programmatic follow up of these patients. In our study site in the province of Newfoundland and Labrador (NL), Canada, there is no centralized, provincial registry of high-risk individuals. There is no continuity or coordination of care providing cancer genetics expertise and no process to ensure that patients are referred to the appropriate specialists or risk management interventions. This paper describes a study protocol to test the feasibility of obtaining and analyzing patient risk management data, specifically patients affected by hereditary breast ovarian cancer syndrome (HBOC; BRCA 1 and BRCA 2 genes) and Lynch syndrome (LS; MLH1, MSH2, MSH6, and PMS2 genes). Through a retrospective cohort study, we will describe these patients' adherence to risk management guidelines and test its relationship to health outcomes, including cancer incidence and stage. Through a qualitative interviews, we will determine the priorities and preferences of patients with any inherited cancer mutation for a follow up navigation model of risk management. Study data will inform a subsequent funding application focused on creating and evaluating a research registry and follow up nurse navigation model. It is not currently known what proportion of cancer mutation carriers are receiving care according to guidelines. Data collected in this study will provide clinical uptake and health outcome information so gaps in care can be identified. Data will also provide patient preference information to inform ongoing and planned research with cancer mutation carriers.
Subject(s)
Genetic Predisposition to Disease , Neoplastic Syndromes, Hereditary , Humans , Retrospective Studies , Follow-Up Studies , Feasibility Studies , Canada , Neoplastic Syndromes, Hereditary/genetics , Neoplastic Syndromes, Hereditary/prevention & control , Registries , Genetic Testing/methodsABSTRACT
Identification of new genetic markers may improve the prediction of colorectal cancer prognosis. Our objective was to examine genome-wide associations of germline genetic variants with disease-specific survival in an analysis of 16,964 cases of colorectal cancer. We analyzed genotype and colorectal cancer-specific survival data from a consortium of 15 studies. Approximately 7.5 million SNPs were examined under the log-additive model using Cox proportional hazards models, adjusting for clinical factors and principal components. Additionally, we ran secondary analyses stratifying by tumor site and disease stage. We used a genome-wide p-value threshold of 5 × 10-8 to assess statistical significance. No variants were statistically significantly associated with disease-specific survival in the full case analysis or in the stage-stratified analyses. Three SNPs were statistically significantly associated with disease-specific survival for cases with tumors located in the distal colon (rs698022, HR = 1.48, CI 1.30-1.69, p = 8.47 × 10-9) and the proximal colon (rs189655236, HR = 2.14, 95% CI 1.65-2.77, p = 9.19 × 10-9 and rs144717887, HR = 2.01, 95% CI 1.57-2.58, p = 3.14 × 10-8), whereas no associations were detected for rectal tumors. Findings from this large genome-wide association study highlight the potential for anatomical-site-stratified genome-wide studies to identify germline genetic risk variants associated with colorectal cancer-specific survival. Larger sample sizes and further replication efforts are needed to more fully interpret these findings.
Subject(s)
Biomarkers, Tumor/genetics , Colorectal Neoplasms/genetics , Genetic Loci , Polymorphism, Single Nucleotide , Adult , Aged , Aged, 80 and over , Colorectal Neoplasms/mortality , Colorectal Neoplasms/pathology , Colorectal Neoplasms/therapy , Databases, Genetic , Female , Genome-Wide Association Study , Humans , Male , Middle Aged , Neoplasm Staging , Risk Assessment , Risk Factors , Young AdultABSTRACT
The effect of somatic mutations and the gene expression profiles on the prognosis is well documented in cancer research. This study was conducted to evaluate the association of GATA3 somatic mutations with tumor features, survival, and expression profiles in breast cancer. Clinicopathological information was compared between TCGA-BRCA patients with GATA3-mutant and non-mutant tumors in all patients as well as in ER-positive subgroup. Cox-regression method was used to evaluate the association of the GATA3 mutation status with overall survival time. Differential gene expression, functional annotation, and protein-protein interaction analyses were performed using edgeR, Metascape, DAVID, STRING and CytoNCA. GATA3-mutant and non-mutant samples had significantly different clinicopathological features (p < 0.05). While GATA3 mutation status was not associated with the overall survival in the entire cohort (padj = 0.52), the GATA3-wild type ER-positive cases had a better prognosis than mutant ones (padj = 0.04). GATA3 expression was higher in tumors than normal tissues. Several pathways were different between mutant and non-mutant groups (p < 0.05). Interleukin-6 was found as the highest scored gene in both comparisons (normal vs. mutant and normal vs. non-mutant groups) in the entire patient and in the ER-positive subgroup, suggesting the association of IL6 with breast tumorigenesis. These findings suggest that GATA3 mutations can be associated with several tumor characteristics and influence the pattern of gene expression. However, GATA3 mutation status seems to be a prognostic factor for the disease only in ER-positive patients.
Subject(s)
Biomarkers, Tumor/genetics , Breast Neoplasms/pathology , Estrogen Receptor alpha/metabolism , GATA3 Transcription Factor/genetics , Mutation , Breast Neoplasms/genetics , Breast Neoplasms/metabolism , Computational Biology/methods , Databases, Genetic , Female , GATA3 Transcription Factor/metabolism , Humans , Middle Aged , Prognosis , Survival Rate , TranscriptomeABSTRACT
We aimed to examine the associations of a genome-wide set of single nucleotide polymorphisms (SNPs) and 254 copy number variations (CNVs) and/or insertion/deletions (INDELs) with clinical outcomes in colorectal cancer patients (n = 505). We also aimed to investigate whether their associations changed (e.g., appeared, diminished) over time. Multivariable Cox proportional hazards and piece-wise Cox regression models were used to examine the associations. The Cancer Genome Atlas (TCGA) datasets were used for replication purposes and to examine the gene expression differences between tumor and nontumor tissue samples. A common SNP (WBP11-rs7314075) was associated with disease-specific survival with P-value of 3.2 × 10-8 . Association of this region with disease-specific survival was also detected in the TCGA patient cohort. Two expression quantitative trait loci (eQTLs) were identified in this locus that were implicated in the regulation of ERP27 expression. Interestingly, expression levels of ERP27 and WBP11 were significantly different between colorectal tumors and nontumor tissues. Three SNPs predicted the risk of recurrent disease only after 5 years postdiagnosis. Overall, our study identified novel variants, one of which also showed an association in the TCGA dataset, but no CNVs/INDELs, that associated with outcomes in colorectal cancer. Three SNPs were candidate predictors of long-term recurrence/metastasis risk.
Subject(s)
Colorectal Neoplasms , Polymorphism, Single Nucleotide , Colorectal Neoplasms/pathology , DNA Copy Number Variations/genetics , DNA-Binding Proteins/genetics , Genetic Predisposition to Disease , Genome-Wide Association Study , Humans , Polymorphism, Single Nucleotide/genetics , Quantitative Trait Loci/genetics , RNA Splicing Factors/geneticsABSTRACT
Colorectal cancer is the third most common cancer with a 5-year survival rate of 30-65%. A portion of the interpatient variability in its clinical outcome is attributed to inherited and somatic genetic factors. Although numerous research articles have investigated these factors in colorectal cancer, there has not been a central resource, such as a public database, that compiles these findings. Here we describe the dbCPCO, a database of genetic variations tested for association with colorectal cancer prognosis and clinical outcome. dbCPCO curates the results of research articles on colorectal cancer that investigate the possible correlation of genetic factors with various patient and tumor characteristics. Literature reports are retrieved from PubMed. The data that meet the inclusion criteria are compiled in a relational database and posted in a dedicated Website. The genetic factors include inherited genetic polymorphisms, and somatic and germline mutations in both nuclear and mitochondrial DNA. As of March 2010, the dbCPCO Website posts 778 scientific findings on 456 polymorphisms, somatic and germline mutations from 189 genes, and genetic loci tested for correlation with clinicopathological features and/or clinical outcome in colorectal cancer. The dbCPCO is periodically updated and freely available for the scientific and medical community at http://www.med.mun.ca/cpco.
Subject(s)
Colorectal Neoplasms/diagnosis , Colorectal Neoplasms/genetics , Databases, Genetic , Genetic Markers , Humans , Internet , PrognosisABSTRACT
Identification of the genetic basis of variable treatment response, prognosis and survival in cancer patients (i.e. personalized medicine) is an important aim in current medicine. Millions of genetic variations exist in the human genome, some of which are already found to be directly involved in variable treatment response and survival among cancer patients. GENETIC VARIATION DATABASES: Special databases curate, compile, organize and post information related to these genetic variations for the scientific community in a user friendly and free-to-access manner via the World Wide Web. FUTURE DIRECTIONS AND CONCLUSION: Clinicians have a critical role in genetic predictive and prognostic studies. In this review, main public-domain databases on genetic variations, including the two comprehensive genetic variation databases (dbSNP and HapMap), a pharmacogenomics database (PharmGKB), two resequencing-based genetic variation databases (SeattleSNPs and EGP), a population-based genetic variation database (JSNPs), and a copy-number variant database (DGV), and their utility in cancer research are discussed. Utilization of these databases can assist clinicians in their studies related to treatment response and prognosis in cancer patients.
Subject(s)
Antineoplastic Agents/pharmacology , Databases, Genetic , Genetic Variation , Neoplasms/drug therapy , Neoplasms/mortality , Animals , DNA Copy Number Variations , Databases, Genetic/trends , Glutathione S-Transferase pi/genetics , Humans , Internet , Neoplasms/genetics , Pharmacogenetics , Polymorphism, Genetic , Predictive Value of Tests , Prognosis , Survival Rate , Treatment OutcomeABSTRACT
Cancer molecular epidemiology traditionally studies the relationship between genetic variations and cancer risk. However, recent studies have also focused on disease outcomes. The application and design of disease outcome studies have been an extension of disease risk assessment. Yet there are a number of unique considerations important in outcome assessments. We review how genetic approaches used for disease susceptibility, such as candidate gene and genome-wide association study (GWAS) approaches, can be adapted carefully to systematically identify cancer prognostic and predictive alleles. We discuss the interrelatedness among the disease susceptibility, treatment response, and prognosis at the genetic level and focus on how the emerging technologies and approaches can uniquely benefit the genetic prognosis studies.