Hereditary colorectal cancer screening: A 10-year longitudinal cohort study following an educational intervention.

Family history (FH) of a first-degree relative with colorectal cancer (CRC) is associated with two to fourfold increased risk, yet screening uptake is suboptimal despite proven mortality reduction. We developed a FH-based CRC Risk Triage/Management tool for family physicians (FPs), and educational booklet for patients with CRC FH. This report describes physician referral and patient screening behavior 5 and 10 years post-educational intervention, and factors associated with screening. Longitudinal cohort study. FPs/patients in Ontario and Newfoundland, Canada were sent questionnaires at baseline (2005), 5 and 10 years (2015) following tool/booklet receipt. FPs were asked about CRC screening, patients about FH, screening type and timing. "Correct" screening was concordance with tool recommendations. Results reported for 29/121 (24%) FPs and 98/297 (33%) patients who completed all 3 questionnaires. Over 10 years 2/3 patients received the correct CRC screening test at appropriate timing (baseline 75%, 5-year 62%, 10-year 65%). About half reported their FP recommended CRC screening (5-year 51%, 10-year 63%). Fewer than half the patients correctly assessed their CRC risk (44%, 40%, 41%). Patients were less likely to have correct screening timing if female (RR 0.78; 95% CI 0.61, 0.99; p = 0.045). Patients were less likely to have both correct test and timing if moderate/high CRC risk (RR 0.66; 95% CI 0.47, 0.93; p = 0.017) and more likely if their physician recommended screening (RR1.69; 95% CI 1.15, 2.49; p = 0.007). Physician discussion of CRC risk and screening can positively impact patient screening behavior. Efforts are particularly needed for women and patients at moderate/high CRC risk.

Universal tumor screening for lynch syndrome: perspectives of patients regarding willingness and informed consent.

Aim: Lynch Syndrome is associated with a significant risk of colorectal carcinoma (CRC) and other cancers. Universal tumor screening is a strategy to identify high-risk individuals by testing all CRC tumors for molecular features suggestive of Lynch Syndrome. Patient interest in screening and preferences for consent have been underexplored. Methods: A postal survey was administered to CRC patients in a Canadian province. Results: Most patients (81.4%) were willing to have tumors tested if universal tumor screening were available and were willing to discuss test results with family members and healthcare professionals. The majority (62.6%) preferred informed consent be obtained prior to screening. Conclusion: Patients were supportive of universal screening. They expected consent to be obtained, contrary to current practice across Canada and elsewhere.

The long-term survival characteristics of a cohort of colorectal cancer patients and baseline variables associated with survival outcomes with or without time-varying effects.

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.

Universal tumor screening for Lynch syndrome: Perceptions of Canadian pathologists and genetic counselors of barriers and facilitators.

BACKGROUND: People at risk of developing hereditary cancers associated with Lynch Syndrome (LS) can be identified through universal screening of colorectal tumors. However, tumor screening practices are variable across Canada and few studies explore the perspectives of genetic counselors and pathologists about tumor screening. This study was conducted to better understand the barriers and facilitators of implementing universal tumor screening in health centers across Canada. METHODS: An online survey about tumor screening programs was administered to genetic counselors and pathologists across Canada through communication channels of professional organizations. It was hosted on SurveyMonkey and accessible from October 2016 to March 2017. RESULTS: Barriers to tumor screening included a lack of sustainable resources, including funding and genetic counselors. Respondents strongly identified the need for a coordinated, interdisciplinary approach to program planning with the "right people at the table." Respondents currently with a screening program provided advice such as carefully designing the program structure, developing patient and family follow-up protocols, and ensuring adequate resources (funding, staff, training for providers) were available prior to program initiation. CONCLUSION: There is no national approach to universal tumor screening in Canada. However, future efforts can be informed by the experiences of those centers that have already created a universal tumor screening program for LS. These data suggest the need for an interdisciplinary approach, initial and sustained funding, and careful advanced planning of program structures and policies.

Telephone versus in-person colorectal cancer risk and screening intervention for first-degree relatives: A randomized controlled trial.

BACKGROUND: Having a first-degree relative (FDR) with colorectal cancer (CRC) is a significant risk factor for CRC. Counseling for FDRs regarding CRC risk factors and personalized risk is important to improve knowledge and screening compliance. METHODS: A 3-arm randomized controlled trial compared tailored in-person and telephone CRC counseling interventions with controls among FDRs who were not mutation carriers for known hereditary cancer syndromes, but who were considered to be at an increased risk based on family history. It was hypothesized that both telephone and in-person approaches would increase CRC knowledge, screening adherence, perceived risk accuracy, and psychosocial functioning compared with controls. The authors anticipated greater satisfaction with the in-person approach. CRC knowledge, risk perception, psychosocial functioning, and intention to screen were assessed at baseline and at 2-week and 2-month follow-ups (primary endpoint). RESULTS: A total of 278 FDRs (mean age, 47.4 years, standard deviation, 11.38 years) participated. At baseline, participants reported low to moderate CRC knowledge and overestimations of risk. Screening adherence was 73.7%. At 2 months, participants in the in-person arm and telephone arm demonstrated improvements in knowledge and perceived risk and were not found to be statistically different from each other. However, when comparing each intervention with controls, knowledge in the in-person arm was found to be statistically significantly higher, but the difference between the telephone and control arms was not. Cancer-related stress reduced over time in all groups. Intervention benefits were maintained at 1 year. Baseline screening intent/adherence were high, and therefore did not reach statistically significant improvement. CONCLUSIONS: Tailored in-person or telephone formats for providing CRC risk counseling, incorporating behavioral interventions, appear to improve knowledge and risk perceptions, with high client satisfaction.

Universal tumor screening for Lynch syndrome: perspectives of Canadian pathologists and genetic counselors.

Universal screening of all newly diagnosed colorectal cancer tumors can identify individuals at high risk for Lynch syndrome (LS), a hereditary cancer syndrome predisposing carriers to increased risk of colorectal, endometrial, and other cancers. To inform planning of a universal tumor screening program for LS in our jurisdiction, we undertook online surveys of Canadian pathologists and genetic counselors to describe existing tumor screening programs. Online surveys were hosted on SurveyMonkey between October 2016 and March 2017. Fifty-three pathologists and 66 genetic counselors completed surveys (total n = 119). While attitudes towards tumor screening were positive, considerable variability was observed in the existence of tumor screening, test ordering criteria, and practices. Most respondents indicated consent was not obtained for tumor screening nor were educational materials provided to patients; however, opting out of additional mutation testing in the event of a positive tumor screen was endorsed. Results add to the growing literature on providers' perspectives on population-based tumor screening programs and inform ways to offer these. Findings highlight the need to develop methods of patient education that allow meaningful opt-out decisions. The variability we observed also suggests the need for national standards and guidance on tumor screening for LS.

Surgical treatment choices for breast cancer in Newfoundland and Labrador: a retrospective cohort study.

BACKGROUND: Mastectomy is often chosen by women for treatment of breast cancer, even when breast-conserving surgery (BCS) is an option. Newfoundland and Labrador has a high mastectomy rate. We documented the number of breast cancers over a given period in the province and their related surgical treatments, and explored the impact of several variables on surgical choice. METHODS: A retrospective cohort design linked diagnosis data from the Newfoundland and Labrador tumour registry to surgery data from the Canadian Institute for Health Information Discharge Abstract Database. Data were extracted for all women aged 19 years or more in whom breast cancer was diagnosed in 2009-2014. RESULTS: A total of 2346 cases of breast cancer with a linked surgical procedure were included. Most operations (1605 [68.4%]) were mastectomy procedures, with the remainder being BCS. Logistic regression analysis revealed that women were 1.82 times (95% confidence interval [CI] 1.64-2.02) more likely to have mastectomy for each unit of stage increase from 0 to IV and 1.15 times (95% CI 1.11-1.21) more likely for each unit of driving time increase. CONCLUSION: Tumour stage and driving time to a radiation facility significantly predicted Newfoundland and Labrador women's surgical treatment choices for breast cancer. Notably, mastectomy was the favoured choice across all age groups, tumour stages and geographical regions of the province. We hope that these results will galvanize efforts to better understand local surgical practices and assist in improving the quality of surgical care of women with breast cancer.

CONTEXTE: Les femmes atteintes d'un cancer du sein optent souvent pour la mastectomie, même lorsque la chirurgie mammaire conservatrice (CMC) est possible. Considérant que la province de Terre-Neuve-et-Labrador enregistre des taux de mastectomie élevés, nous y avons recensé durant une période donnée les cas de cancer du sein et les traitements chirurgicaux associés, et avons étudié l'influence de plusieurs variables sur le choix d'intervention. MÉTHODES: Suivant un modèle de cohorte rétrospective, nous avons apparié les données diagnostiques du registre des cancers de Terre-Neuve-et-Labrador aux données chirurgicales correspondantes de la Base de données sur les congés des patients de l'Institut canadien d'information sur la santé. Nous avons extrait les données de toutes les femmes de 19 ans et plus qui ont reçu un diagnostic de cancer du sein entre 2009 et 2014. RÉSULTATS: Nous avons retenu 2346 cas de cancer du sein avec prise en charge chirurgicale. La majorité des interventions (1605, ou 68,4 %) étaient des mastectomies; les autres étaient des CMC. Une analyse de régression logistique a révélé qu'avec chaque augmentation unitaire du stade (de 0 à 4), les femmes devenaient 1,82 fois plus susceptibles d'opter pour la mastectomie (intervalle de confiance [IC] de 95 % 1,64 à 2,02), et 1,15 fois plus susceptibles de le faire avec chaque augmentation unitaire du temps de conduite (IC de 95 % 1,11 à 1,21). CONCLUSION: Le stade de la tumeur et le temps nécessaire pour se rendre dans un établissement de radiothérapie étaient des facteurs prédictifs significatifs du choix de traitement chirurgical du cancer du sein chez les femmes de Terre-Neuve-et-Labrador. Fait intéressant : tous les groupes, quels que soient leur âge, le stade de leur tumeur et leur région de la province, avaient une préférence pour la mastectomie. Nous espérons que ces résultats mèneront à d'autres analyses des pratiques chirurgicales locales et contribueront à améliorer la qualité de la prise en charge chirurgicale des femmes atteintes d'un cancer du sein.

Association of rs2282679 A>C polymorphism in vitamin D binding protein gene with colorectal cancer risk and survival: effect modification by dietary vitamin D intake.

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.

Quality of life following prophylactic gynecological surgery: experiences of female Lynch mutation carriers.

Lynch syndrome (LS) is a genetic condition conferring an elevated risk of gastrointestinal, gynecologic and other malignancies, often before the age of 50. Current guidelines recommend prophylactic gynecologic surgery to manage inherited cancers for female mutation carriers. Data is lacking on women's quality of life following surgery. In this pilot study, we explored how women described their quality of life post-prophylactic gynecologic surgery and the factors that affected post-surgery experiences. A qualitative interview study was the chosen design. Ten female Lynch syndrome mutation carriers were interviewed by phone. Interviews were transcribed and analysed for themes relating to quality of life post-surgery using content analysis and constant comparison. Women largely reported doing well since their surgeries, though all described deleterious impacts on quality of life. Positive impacts of surgery included a reduction in cancer worry and an increase in healthy lifestyle behaviors, while negative impacts due to the sudden onset of menopause and impact on sexual function were common. Pre-surgical knowledge, drug and topical therapies, and post-surgical support all contributed to a positive quality of life. This small pilot study revealed increased endocrine symptoms and a negative impact on sexual health following prophylactic gynecological surgery. Women who were informed of potential symptoms pre-surgery coped better with surgical outcomes, as did women using some form of HRT. All women experienced reduced cancer worry post-surgery. Findings highlight areas for discussion in pre-operative settings (e.g., sexual health), as well as the need for better follow-up support post-surgery.

Vitamin D receptor and calcium-sensing receptor polymorphisms and colorectal cancer survival in the Newfoundland population.

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.

Germline INDELs and CNVs in a cohort of colorectal cancer patients: their characteristics, associations with relapse-free survival time, and potential time-varying effects on the risk of relapse.

INDELs and CNVs are structural variations that may play roles in cancer susceptibility and patient outcomes. Our objectives were a) to computationally detect and examine the genome-wide INDEL/CNV profiles in a cohort of colorectal cancer patients, and b) to examine the associations of frequent INDELs/CNVs with relapse-free survival time. We also identified unique variants in 13 Familial Colorectal Cancer Type X (FCCX) cases. The study cohort consisted of 495 colorectal cancer patients. QuantiSNP and PennCNV algorithms were utilized to predict the INDELs/CNVs using genome-wide signal intensity data. Duplex PCR was used to validate predictions for 10 variants. Multivariable Cox regression models were used to test the associations of 106 common variants with relapse-free survival time. Score test and the multivariable Cox proportional hazards models with time-varying coefficients were applied to identify the variants with time-varying effects on the relapse-free survival time. A total of 3486 distinct INDELs/CNVs were identified in the patient cohort. The majority of these variants were rare (83%) and deletion variants (81%). The results of the computational predictions and duplex PCR results were highly concordant (93-100%). We identified four promising variants significantly associated with relapse-free survival time (P < 0.05) in the multivariable Cox proportional hazards regression models after adjustment for clinical factors. More importantly, two additional variants were identified to have time-varying effects on the risk of relapse. Finally, 58 rare variants were identified unique to the FCCX cases; none of them were detected in more than one patient. This is one of the first genome-wide analyses that identified the germline INDEL/CNV profiles in colorectal cancer patients. Our analyses identified novel variants and genes that can biologically affect the risk of relapse in colorectal cancer patients. Additionally, for the first time, we identified germline variants that can potentially be early-relapse markers in colorectal cancer.

No associations of a set of SNPs in the Vascular Endothelial Growth Factor (VEGF) and Matrix Metalloproteinase (MMP) genes with survival of colorectal cancer patients.

In this study, we aimed to investigate the associations of genetic variations within select genes functioning in angiogenesis, lymph-angiogenesis, and metastasis pathways and the risk of outcome in colorectal cancer patients. We followed a two-stage analysis: First, 381 polymorphisms from 30 genes (eight Vascular Endothelial Growth Factor (VEGF) and 22 Matrix Metalloproteinase [MMP] genes) were investigated in the discovery cohort (n = 505). Then, 16 polymorphisms with the lowest P-value in this analysis were investigated in a separate replication cohort (n = 247). Genotypes were obtained using the Illumina(®) HumanOmni-1-Quad (discovery cohort) and Sequenom MassArray(®) (replication cohort) platforms. The primary outcome measure was overall survival (OS). Kaplan-Meier, univariate and multivariable Cox regression methods were used to test the associations between genotypes and OS. Four SNPs (rs12365082, rs11225389, rs11225388, and rs2846707) had the univariate analysis P < 0.05 in both the discovery and replication cohorts. These SNPs are in linkage disequilibrium with each other to varying extent and are located in the MMP8 and MMP27 genes. In the multivariable analysis adjusting for age, stage, and microsatellite instability status, three of these SNPs (rs12365082, rs11225389, rs11225388) were independent predictors of OS (P < 0.05) in the discovery cohort. However, the same analysis in the replication cohort did not yield statistically significant results. Overall, while the genetic variations in the VEGF and MMP genes are attractive candidates as prognostic markers, our study showed no evidence of associations of a large set of SNPs in these genes and overall survival of colorectal cancer patients in our study.

Promoter methylation of ITF2, but not APC, is associated with microsatellite instability in two populations of colorectal cancer patients.

BACKGROUND: Aberrant Wnt signaling activation occurs commonly in colorectal carcinogenesis, leading to upregulation of many target genes. APC (adenomatous polyposis coli) is an important component of the ß-catenin destruction complex, which regulates Wnt signaling, and is often mutated in colorectal cancer (CRC). In addition to mutational events, epigenetic changes arise frequently in CRC, specifically, promoter hypermethylation which silences tumor suppressor genes. APC and the Wnt signaling target gene ITF2 (immunoglobulin transcription factor 2) incur hypermethylation in various cancers, however, methylation-dependent regulation of these genes in CRC has not been studied in large, well-characterized patient cohorts. The microsatellite instability (MSI) subtype of CRC, featuring DNA mismatch repair deficiency and often promoter hypermethylation of MutL homolog 1 (MLH1), has a favorable outcome and is characterized by different chemotherapeutic responses than microsatellite stable (MSS) tumors. Other epigenetic events distinguishing these subtypes have not yet been fully elucidated. METHODS: Here, we quantify promoter methylation of ITF2 and APC by MethyLight in two case-case studies nested in population-based CRC cohorts from the Ontario Familial Colorectal Cancer Registry (n = 330) and the Newfoundland Familial Colorectal Cancer Registry (n = 102) comparing MSI status groups. RESULTS: ITF2 and APC methylation are significantly associated with tumor versus normal state (both P < 1.0 × 10(-6)). ITF2 is methylated in 45.8% of MSI cases and 26.9% of MSS cases and is significantly associated with MSI in Ontario (P = 0.002) and Newfoundland (P = 0.005) as well as the MSI-associated feature of MLH1 promoter hypermethylation (P = 6.72 × 10(-4)). APC methylation, although tumor-specific, does not show a significant association with tumor subtype, age, gender, or stage, indicating it is a general tumor-specific CRC biomarker. CONCLUSIONS: This study demonstrates, for the first time, MSI-associated ITF2 methylation, and further reveals the subtype-specific epigenetic events modulating Wnt signaling in CRC.

Mitochondrial DNA polymorphisms, its copy number change and outcome in colorectal cancer.

BACKGROUND: Mitochondrion is a small organelle inside the eukaryotic cells. It has its own genome (mtDNA) and encodes for proteins that are critical for energy production and cellular metabolism. Mitochondrial dysfunctions have been implicated in cancer progression and may be related to poor prognosis in cancer patients. In this study we hypothesized that genetic variations in mtDNA are associated with clinical outcome in colorectal cancer patients. METHODS: We tested the associations of six mtDNA polymorphisms [MitoT479C, MitoT491C, MitoT10035C, MitoA13781G, 10398 (A/G), and 16189 (T/C)] and the mtDNA copy number change with overall survival (OS) and disease-free survival (DFS) times. Two mtDNA polymorphisms were genotyped using the TaqMan(®) SNP genotyping technique and the genotypes for the remaining four mtDNA polymorphisms were obtained by the Illumina(®) HumanOmni1-Quad genome wide SNP genotyping platform in 536 patients. The mtDNA copy number change (in tumor tissues with respect to non-tumor tissues) was estimated using the quantitative real time polymerase chain reaction for 274 patients. Associations of these mtDNA variations with OS and DFS were tested using the Cox regression method. RESULTS: In both univariate and multivariable analyses, none of the six mtDNA polymorphisms were associated with OS or DFS. 39.6 and 60.4% of the patients had increased and decreased mtDNA copy number in their tumor tissues when compared to their non-tumor rectum or colon tissues, respectively. However, in contrast to previous findings, the change in the mtDNA copy number was associated with neither OS nor DFS in our patient cohort. CONCLUSIONS: Our results suggest that the mitochondrial genetic markers investigated in this study are not associated with outcome in colorectal cancer.

A Survival Association Study of 102 Polymorphisms Previously Associated with Survival Outcomes in Colorectal Cancer.

Several published studies identified associations of a number of polymorphisms with a variety of survival outcomes in colorectal cancer. In this study, we aimed to explore 102 previously reported common genetic polymorphisms and their associations with overall survival (OS) and disease-free survival (DFS) in a colorectal cancer patient cohort from Newfoundland (n = 505). Genotypes were obtained using a genomewide SNP genotyping platform. For each polymorphism, the best possible genetic model was estimated for both overall survival and disease-free survival using a previously published approach. These SNPs were then analyzed under their genetic models by Cox regression method. Correction for multiple comparisons was performed by the False Discovery Rate (FDR) method. Univariate analysis results showed that RRM1-rs12806698, IFNGR1-rs1327474, DDX20-rs197412, and PTGS2-rs5275 polymorphisms were nominally associated with OS or DFS (p < 0.01). In stage-adjusted analysis, the nominal associations of DDX20-rs197412, PTGS2-rs5275, and HSPA5-rs391957 with DFS were detected. However, after FDR correction none of these polymorphisms remained significantly associated with the survival outcomes. We conclude that polymorphisms investigated in this study are not associated with OS or DFS in our colorectal cancer patient cohort.

A genome wide association study on Newfoundland colorectal cancer patients' survival outcomes.

BACKGROUND: In this study we performed genome-wide association studies to identify candidate SNPs that may predict the risk of disease outcome in colorectal cancer. METHODS: Patient cohort consisted of 505 unrelated patients with Caucasian ancestry. Germline DNA samples were genotyped using the Illumina® human Omni-1quad SNP chip. Associations of SNPs with overall and disease free survivals were examined primarily for 431 patients with microsatellite instability-low (MSI-L) or stable (MSS) colorectal tumors using Cox proportional hazards method adjusting for clinical covariates. Bootstrap method was applied for internal validation of results. As exploratory analyses, association analyses for the colon (n = 334) and rectal (n = 171) cancer patients were also performed. RESULTS: As a result, there was no SNP that reached the genomewide significance levels (p < 5x10(-8)) in any of the analyses. A small number of genetic markers (n = 10) showed nominal associations (p <10(-6)) for MSS/MSI-L, colon, or rectal cancer patient groups. These markers were located in two non-coding RNA genes or intergenic regions and none were amino acid substituting polymorphisms. Bootstrap analysis for the MSS/MSI-L cohort data suggested the robustness of the observed nominal associations. CONCLUSIONS: Likely due to small number of patients, our study did not identify an acceptable level of association of SNPs with outcome in MSS/MSI-L, colon, or rectal cancer patients. A number of SNPs with sub-optimal p-values were, however, identified; these loci may be promising and examined in other larger-sized patient cohorts.

Decisions about prophylactic gynecologic surgery: a qualitative study of the experience of female Lynch syndrome mutation carriers.

BACKGROUND: Women who carry a mutation for Lynch syndrome face complex decisions regarding strategies for managing their increased cancer risks. At present, there is limited understanding of the factors influencing women's prophylactic surgery decisions. METHODS: As part of an exploratory pilot project, semi-structured interviews were conducted with 10 women who were Lynch syndrome mutation carriers and had made prophylactic surgery decisions. Nine of 10 women had chosen to undergo prophylactic hysterectomy and/or oophorectomy as a means of managing their increased gynecological cancer risks. RESULTS: Study findings revealed that surgery decisions were influenced by multiple factors, including demographic variables such as age and parity, as well as psychosocial factors such as cancer worry, in addition to personal and social knowledge of gynecological cancer. While all women were satisfied with their surgery decision, some reported they were not fully informed about the negative impact on their quality of life post-surgery (e.g., complications of surgically-induced menopause), nor about the potential for, or risks and benefits of, hormone replacement therapy. CONCLUSIONS: Study findings highlight some of the factors associated with prophylactic surgery decisions and women's perceptions about pre-surgical information provision and needs. Suggestions are made for improving the information and support provided to female carriers of a Lynch syndrome mutation.

Examining the polymorphisms in the hypoxia pathway genes in relation to outcome in colorectal cancer.

INTRODUCTION: Colorectal cancer is a common malignancy. Identification of genetic prognostic markers may help prognostic estimations in colorectal cancer. Genes that regulate response to hypoxia and other genes that are regulated under the hypoxic conditions have been shown to play roles in cancer progression. In this study, we hypothesized that genetic variations in the hypoxia pathway genes were associated with the risk of outcome in colorectal cancer patients. METHODS: This study was performed in two phases. In the first phase, 49 SNPs from six hypoxia pathway genes (HIF1A, HIF1B, HIF2A, LOX, MIF and CXCL12) in 272 colorectal cancer patients were analyzed. In the second phase, 77 SNPs from seven hypoxia pathway genes (HIF1A, HIF1B, HIF2A, HIF2B, HIF3A, LOX and CXCL12) were analyzed in an additional cohort of 535 patients. Kaplan Meier, Cox univariate and multivariable regression analyses were performed to analyze the relationship between the SNPs and overall survival (OS), disease free survival (DFS) or disease specific survival (DSS). Since this was a hypothesis-generating study, no correction for multiple testing was applied. RESULTS: In phase I, one SNP (HIF2A rs11125070) was found to be associated with DFS in multivariable analysis; yet association of a proxy polymorphism (HIF2A rs4953342) was not detected in the phase II patient cohort. In phase II, associations of two SNPs (HIF2A rs4953352 and HIF2B rs12593988) were significant in both OS and DFS multivariable analyses. However, association of HIF2A rs4953352 was not replicated in the phase I cohort using a proxy SNP (HIF2A rs6706003). CONCLUSION: Overall, our study did not find a convincing evidence of association of the investigated polymorphisms with the disease outcomes in colorectal cancer.

Dietary N-nitroso compounds and risk of colorectal cancer: a case-control study in Newfoundland and Labrador and Ontario, Canada.

Several N-nitroso compounds (NOC) have been shown to be carcinogenic in a variety of laboratory animals, but evidence of their carcinogenicity in humans is lacking. We aimed to examine the association between NOC intake and colorectal cancer (CRC) risk and possible effect modification by vitamins C and E and protein in a large case-control study carried out in Newfoundland and Labrador and Ontario, Canada. A total of 1760 case patients with pathologically confirmed adenocarcinoma and 2481 population controls were asked to complete a self-administered FFQ to evaluate their dietary intakes 1 year before diagnosis (for cases) or interview (for controls). Adjusted OR and 95 % CI were calculated across the quintiles of NOC (measured by N-nitrosodimethylamine (NDMA)) intake and relevant food items using unconditional logistic regression. NDMA intake was found to be associated with a higher risk of CRC (highest v. lowest quintiles: OR 1·42, 95 % CI 1·03, 1·96; P for trend = 0·005), specifically for rectal carcinoma (OR 1·61, 95 % CI 1·11, 2·35; P for trend = 0·01). CRC risk also increased with the consumption of NDMA-containing meats when the highest tertile was compared with the lowest tertile (OR 1·47, 95 % CI 1·03, 2·10; P for trend = 0·20). There was evidence of effect modification between dietary vitamin E and NDMA. Individuals with high NDMA and low vitamin E intakes had a significantly increased risk than those with both low NDMA and low vitamin E intakes (OR 3·01, 95 % CI 1·43, 6·51; P for interaction = 0·017). The present results support the hypothesis that NOC intake may be positively associated with CRC risk in humans. Vitamin E, which inhibits nitrosation, could modify the effect of NDMA on CRC risk.

MTHFR Glu429Ala and ERCC5 His46His polymorphisms are associated with prognosis in colorectal cancer patients: analysis of two independent cohorts from Newfoundland.

INTRODUCTION: In this study, 27 genetic polymorphisms that were previously reported to be associated with clinical outcomes in colorectal cancer patients were investigated in relation to overall survival (OS) and disease free survival (DFS) in colorectal cancer patients from Newfoundland. METHODS: The discovery and validation cohorts comprised of 532 and 252 patients, respectively. Genotypes of 27 polymorphisms were first obtained in the discovery cohort and survival analyses were performed assuming the co-dominant genetic model. Polymorphisms associated with disease outcomes in the discovery cohort were then investigated in the validation cohort. RESULTS: When adjusted for sex, age, tumor stage and microsatellite instability (MSI) status, four polymorphisms were independent predictors of OS in the discovery cohort MTHFR Glu429Ala (HR: 1.72, 95%CI: 1.04-2.84, p = 0.036), ERCC5 His46His (HR: 1.78, 95%CI: 1.15-2.76, p = 0.01), SERPINE1 -675indelG (HR: 0.52, 95%CI: 0.32-0.84, p = 0.008), and the homozygous deletion of GSTM1 gene (HR: 1.4, 95%CI: 1.03-1.92, p = 0.033). In the validation cohort, the MTHFR Glu429Ala polymorphism was associated with shorter OS (HR: 1.71, 95%CI: 1.18-2.49, p = 0.005), although with a different genotype than the discovery cohort (CC genotype in the discovery cohort and AC genotype in the validation cohort). When stratified based on treatment with 5-Fluorouracil (5-FU)-based regimens, this polymorphism was associated with reduced OS only in patients not treated with 5-FU. In the DFS analysis, when adjusted for other variables, the TT genotype of the ERCC5 His46His polymorphism was associated with shorter DFS in both cohorts (discovery cohort: HR: 1.54, 95%CI: 1.04-2.29, p = 0.032 and replication cohort: HR: 1.81, 95%CI: 1.11-2.94, p = 0.018). CONCLUSIONS: In this study, associations of the MTHFR Glu429Ala polymorphism with OS and the ERCC5 His46His polymorphism with DFS were identified in two colorectal cancer patient cohorts. Our results also suggest that the MTHFR Glu429Ala polymorphism may be an adverse prognostic marker in patients not treated with 5-FU.