Before SNP-based risk can be incorporated in colorectal cancer (CRC) screening, the ability of these SNPs to estimate CRC risk for persons with and without a family history of CRC, and the screening ...implications need to be determined. We estimated the association with CRC of a 45 SNP-based risk using 1181 cases and 999 controls, and its correlation with CRC risk predicted from detailed family history. We estimated the predicted change in the distribution across predefined risk categories, and implications for recommended screening commencement age, from adding SNP-based risk to family history. The inter-quintile risk ratio for colorectal cancer risk of the SNP-based risk was 3.28 (95% CI 2.54–4.22). SNP-based and family history-based risks were not correlated (
r
= 0.02). For persons with no first-degree relatives with CRC, screening could commence 4 years earlier for women (5 years for men) in the highest quintile of SNP-based risk. For persons with two first-degree relatives with CRC, screening could commence 16 years earlier for men and women in the highest quintile, and 7 years earlier for the lowest quintile. This 45 SNP panel in conjunction with family history, can identify people who could benefit from earlier screening. Risk reclassification by 45 SNPs could inform targeted screening for CRC prevention, particularly in clinical genetics settings when mutations in high-risk genes cannot be identified. Yet to be determined is cost-effectiveness, resources requirements, community, patient and clinician acceptance, and feasibility with potentially ethical, legal and insurance implications.
Although the association of germline
BRCA2
mutations with pancreatic adenocarcinoma is well established, the role of
BRCA1
mutations is less clear. We hypothesized that the loss of heterozygosity at ...the
BRCA1
locus occurs in pancreatic cancers of germline
BRCA1
mutation carriers, acting as a “second-hit” event contributing to pancreatic tumorigenesis. Seven germline
BRCA1
mutation carriers with pancreatic adenocarcinoma and nine patients with sporadic pancreatic cancer were identified from clinic- and population-based registries. DNA was extracted from paraffin-embedded tumor and nontumor samples. Three polymorphic microsatellite markers for the
BRCA1
gene, and an internal control marker on chromosome 16p, were selected to test for the loss of heterozygosity. Tumor DNA demonstrating loss of heterozygosity in
BRCA1
mutation carriers was sequenced to identify the retained allele. The loss of heterozygosity rate for the control marker was 20%, an expected baseline frequency. Loss of heterozygosity at the
BRCA1
locus was 5/7 (71%) in
BRCA1
mutation carriers; tumor DNA was available for sequencing in 4/5 cases, and three demonstrated loss of the wild-type allele. Only 1/9 (11%) sporadic cases demonstrated loss of heterozygosity at the
BRCA1
locus. Loss of heterozygosity occurs frequently in pancreatic cancers of germline
BRCA1
mutation carriers, with loss of the wild-type allele, and infrequently in sporadic cancer cases. Therefore,
BRCA1
germline mutations likely predispose to the development of pancreatic cancer, and individuals with these mutations may be considered for pancreatic cancer-screening programs.
Abstract Objective To determine whether risk of endometrial cancer for women without a germline mutation in a DNA mismatch repair (MMR) gene depends on family history of endometrial or colorectal ...cancer. Methods We retrospectively followed a cohort of 79,166 women who were recruited to the Colon Cancer Family Registry, after exclusion of women who were relatives of a carrier of a MMR gene mutation. The Kaplan–Meier failure method was used to estimate the cumulative risk of endometrial cancer. Cox regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for association between family history of endometrial or colorectal cancer and risk of endometrial cancer. Results A total of 628 endometrial cancer cases were observed, with mean age at diagnosis of 54.4 (standard deviation: 15.7) years. The cumulative risk of endometrial cancer to age 70 years was estimated to be 0.94% (95% CI 0.83–1.05) for women with no family history of endometrial cancer, and 3.80% (95% CI 2.75–4.98) for women with at least one first- or second-degree relative with endometrial cancer. Compared with women without family history, we found an increased risk of endometrial cancer for women with at least one first- or second-degree relative with endometrial cancer (HR 3.66, 95% CI 2.63–5.08), and for women with one first-degree relative with colorectal cancer diagnosed at age < 50 years (HR 1.48, 95% CI 1.15–1.91). Conclusion An increased risk of endometrial cancer is associated with a family history of endometrial cancer or early-onset colorectal cancer for women without a MMR gene mutation, indicating for potential underlying genetic and environmental factors shared by colorectal and endometrial cancers other than caused by MMR gene mutations.
Although genome-wide association studies (GWAS) have separately identified many genetic susceptibility loci for ulcerative colitis (UC), Crohn's disease (CD) and colorectal cancer (CRC), there has ...been no large-scale examination for pleiotropy, or shared genetic susceptibility, for these conditions. We used logistic regression modeling to examine the associations of 181 UC and CD susceptibility variants previously identified by GWAS with risk of CRC using data from the Genetics and Epidemiology of Colorectal Cancer Consortium and the Colon Cancer Family Registry. We also examined associations of significant variants with clinical and molecular characteristics in a subset of the studies. Among 11794 CRC cases and 14190 controls, rs11676348, the susceptibility single nucleotide polymorphism (SNP) for UC, was significantly associated with reduced risk of CRC (P = 7E-05). The multivariate-adjusted odds ratio of CRC with each copy of the T allele was 0.93 (95% CI 0.89-0.96). The association of the SNP with risk of CRC differed according to mucinous histological features (P heterogeneity = 0.008). In addition, the (T) allele was associated with lower risk of tumors with Crohn's-like reaction but not tumors without such immune infiltrate (P heterogeneity = 0.02) and microsatellite instability-high (MSI-high) but not microsatellite stable or MSI-low tumors (P heterogeneity = 0.03). The minor allele (T) in SNP rs11676348, located downstream from CXCR2 that has been implicated in CRC progression, is associated with a lower risk of CRC, particularly tumors with a mucinous component, Crohn's-like reaction and MSI-high. Our findings offer the promise of risk stratification of inflammatory bowel disease patients for complications such as CRC.
Abstract Objective The brief Family History Questionnaire (bFHQ) was developed to identify endometrial cancer patients whose family histories suggest Lynch syndrome (LS). We compared the bFHQ, ...extended Family History Questionnaire (eFHQ) and dictated medical records (DMRs) to determine which family history screening strategy is superior in identifying LS in unselected women with newly diagnosed endometrial cancer that have undergone universal germline testing. Methods Prospective cohort study recruited women with newly diagnosed endometrial cancer to evaluate screening strategies to identify LS. Participants completed bFHQ and eFHQ, had tumor assessed with immunohistochemistry (IHC) for mismatch repair proteins (MMR) and micro-satellite instability testing and underwent universal germline testing for LS. The sensitivity, specificity, positive and negative predictive values (PPV, NPV) were compared between the family history screening strategies as well as IHC. Results 118 of 182 eligible patients (65%) consented; 87 patients (74%) were evaluable with both family history and germline mutation status. Median age was 61 years (range 26–91). All 7 patients with confirmed LS were correctly identified by bFHQ, compared to 5 and 4 by eFHQ and DMR, respectively. The sensitivity, specificity, PPV and NPV values of bFHQ were 100%, 76.5%, 25.9% and 100%, respectively, performing similar to IHC testing. While eFHQ was more specific than bFHQ (86.7% vs. 76.5%, P = 0.007), 2 cases of LS were missed. Conclusions The patient-administered bFHQ effectively identified women with confirmed LS and is a good screening tool to triage women with endometrial cancer for further genetic assessment.
A locus on human chromosome 11q23 tagged by marker rs3802842 was associated with colorectal cancer (CRC) in a genome‐wide association study; this finding has been replicated in case–control studies ...worldwide. In order to identify biologic factors at this locus that are related to the etiopathology of CRC, we used microarray‐based target selection methods, coupled to next‐generation sequencing, to study 103 kb at the 11q23 locus. We genotyped 369 putative variants from 1,030 patients with CRC (cases) and 1,061 individuals without CRC (controls) from the Ontario Familial Colorectal Cancer Registry. Two previously uncharacterized genes, COLCA1 and COLCA2, were found to be co‐regulated genes that are transcribed from opposite strands. Expression levels of COLCA1 and COLCA2 transcripts correlate with rs3802842 genotypes. In colon tissues, COLCA1 co‐localizes with crystalloid granules of eosinophils and granular organelles of mast cells, neutrophils, macrophages, dendritic cells and differentiated myeloid‐derived cell lines. COLCA2 is present in the cytoplasm of normal epithelial, immune and other cell lineages, as well as tumor cells. Tissue microarray analysis demonstrates the association of rs3802842 with lymphocyte density in the lamina propria (p = 0.014) and levels of COLCA1 in the lamina propria (p = 0.00016) and COLCA2 (tumor cells, p = 0.0041 and lamina propria, p = 6 × 10–5). In conclusion, genetic, expression and immunohistochemical data implicate COLCA1 and COLCA2 in the pathogenesis of colon cancer. Histologic analyses indicate the involvement of immune pathways.
What's new?
Genome‐wide association studies have identified genomic loci associated with increased cancer risk, but the precise identification of the genes supporting cancer development within these loci remains challenging. The authors performed high‐resolution mapping of a region on chromosome 11q23 previously associated with colorectal cancer predisposition. They identified COLCA1 and COLCA2, two coordinately regulated genes for which transcript and protein expression correlated with the presence or absence of the single‐nucleotide polymorphism (SNP) identified in the region. In addition, the presence of the SNP as well as expression levels of the candidate genes correlated with a characteristic histological pattern of lymphocyte infiltration in the lamina propria of the colon tissue. These studies link colon cancer risk with immune pathways providing new opportunities for improved colon cancer diagnostic tools, novel predictive biomarkers, and potential therapeutic strategies modulating the tumor microenvironment.
Deep learning may detect biologically important signals embedded in tumor morphologic features that confer distinct prognoses. Tumor morphologic features were quantified to enhance patient risk ...stratification within DNA mismatch repair (MMR) groups using deep learning. Using a quantitative segmentation algorithm (QuantCRC) that identifies 15 distinct morphologic features, we analyzed 402 resected stage III colon carcinomas 191 deficient (d)-MMR; 189 proficient (p)-MMR from participants in a phase III trial of FOLFOX-based adjuvant chemotherapy. Results were validated in an independent cohort (176 d-MMR; 1,094 p-MMR). Association of morphologic features with clinicopathologic variables, MMR, KRAS, BRAFV600E, and time-to-recurrence (TTR) was determined. Multivariable Cox proportional hazards models were developed to predict TTR. Tumor morphologic features differed significantly by MMR status. Cancers with p-MMR had more immature desmoplastic stroma. Tumors with d-MMR had increased inflammatory stroma, epithelial tumor-infiltrating lymphocytes (TIL), high-grade histology, mucin, and signet ring cells. Stromal subtype did not differ by BRAFV600E or KRAS status. In p-MMR tumors, multivariable analysis identified tumor-stroma ratio (TSR) as the strongest feature associated with TTR HRadj 2.02; 95% confidence interval (CI), 1.14-3.57; P = 0.018; 3-year recurrence: 40.2% vs. 20.4%; Q1 vs. Q2-4. Among d-MMR tumors, extent of inflammatory stroma (continuous HRadj 0.98; 95% CI, 0.96-0.99; P = 0.028; 3-year recurrence: 13.3% vs. 33.4%, Q4 vs. Q1) and N stage were the most robust prognostically. Association of TSR with TTR was independently validated. In conclusion, QuantCRC can quantify morphologic differences within MMR groups in routine tumor sections to determine their relative contributions to patient prognosis, and may elucidate relevant pathophysiologic mechanisms driving prognosis.
A deep learning algorithm can quantify tumor morphologic features that may reflect underlying mechanisms driving prognosis within MMR groups. TSR was the most robust morphologic feature associated with TTR in p-MMR colon cancers. Extent of inflammatory stroma and N stage were the strongest prognostic features in d-MMR tumors. TIL density was not independently prognostic in either MMR group.
The left renal vein (LRV) may be used for venous reconstruction during hepato-pancreato-biliary (HPB) surgery, although concerns exist about compromising renal function. This study aimed to determine ...renal outcomes following LRV harvest during HPB resections.
Circumferential PV/SMV resections from 2008 to 2014 were included within two groups (LRV harvest, Control). Absolute and change in Creatinine (Cr) and estimated GFR (eGFR), and rates of acute kidney injury (AKI) and chronic kidney disease (CKD), were compared. Multivariate logistic regression analyses were performed.
76 patients were included (LRV n = 17, Control n = 59). Median Cr and eGFR did not change within groups, although change in eGFR differed between groups at postoperative day (POD) 3 (−4.3 vs. 12.8, p = 0.0035) and 7 (−1.8 vs. 12.4, p = 0.0074). AKI occurred more frequently in the LRV group at POD1 (5/17 vs. 4/59, p = 0.023) and POD3 (5/17 vs. 3/59, p = 0012), with no difference in CKD between groups (2/11 vs. 5/33 at 3 months, p = 0.99). LRV harvest was an independent risk factor for AKI at POD1 and POD3, but not thereafter.
Patients who undergo LRV harvest experience a higher rate of AKI in the first three post-operative days. LRV harvest during pancreas resection does not impact on long-term renal function.
Colorectal cancer remains a significant cause of mortality and morbidity in North America. Colorectal cancer survival is highly dependent on stage at diagnosis, therefore it is important to identify ...factors related to stage. This study evaluated the association between subject factors (e.g., colonic screening, family history) and stage of colorectal cancer at diagnosis.
Population-based colorectal cancer cases recruited by the Ontario Familial Colon Cancer Registry between 1997 and 1999 were staged according to the tumor-nodal-metastasis (TNM) staging system and classified as early (TNM I/II) or late (TNM III/IV) stage. Epidemiologic information and stage was available for 768 cases. Multivariate logistic regression was used to obtain odds ratios (OR) estimates.
Having had screening endoscopy reduced the risk of late stage diagnosis (OR = 0.46, 95% CI 0.22-0.98). Being older (>45 yr) was associated with a reduced risk of late stage cancer (OR = 0.36, 95% CI 0.18-0.74), as was having a first degree relative with colorectal cancer (OR =0.66, 95% CI 0.46-0.95). Rural residence (OR = 1.48, 95% CI 1.01-2.17) and non-white ethnicity (OR = 3.34, 95% CI 1.20-9.36) were associated with an increased risk of late stage cancer.
Several factors are independently associated with late stage colorectal cancer. Colorectal cancer screening awareness and education programs need to consider targeting persons most likely to present with late stage colorectal cancer.
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