Notch and Wnt signaling function together to regulate colonic progenitor cell division and differentiation. Studies in mice have also shown that Notch signaling is required for adenoma formation in response to elevated Wnt-pathway signaling that occurs in the APCMin mouse model of human adenomatous polyposis coli. We therefore used in situ hybridization to analyze expression of Notch ligands, receptors and fringe genes, as well as the Notch target gene, HES1, in human colorectal cancer (CRC). In a small cohort of tumors, JAGGED ligands, NOTCH1, LFNG and HES1 were expressed at levels similar to, or higher than, levels observed in the crypt. To explore the possibility that Notch signaling may play a quantitative role in human CRC we next analyzed HES1 mRNA expression in 130 tumors, each associated with outcome data. The vast majority of these tumors expressed HES1, although at varying levels. Absolute expression levels did not correlate with patient survival. These results establish that JAG ligands and NOTCH1, as well as Notch receptor activation are consistent features of human CRC and support the notion that many of these tumors, like the APCMin mouse, may respond to anti-Notch therapeutic regimes.
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Case-control studies of fatal cancers often rely on proxy respondents. Therefore, it is important to determine the completeness and accuracy of proxy-reported information. We evaluated proxy reports using the Ontario Familial Colon Cancer Registry epidemiology questionnaire. A proxy questionnaire was completed by spouses or relatives identified by a sample of participating cases. Item non-response and percentage agreement (between case and proxy reports) were assessed. More than 30% of proxies were unable to report on physical activity, gynecological surgery, alcohol intake, weight 20 years ago, and oral contraceptive use. Proxy reports of medical history and bowel screening varied, the percentage missing ranging from 5% for diabetes to 44% for familial polyposis in the case of medical history, and from 4% for colonoscopy to 27% for hemoccult tests in the case of screening. Agreement between case and proxy report was good to excellent for colonic screening, most medical history, and for reproductive, medication and vitamin use variables (74% to 100%). It is useful to collect proxy information on such variables as medical history, parity, colonic screening and vitamin use, whereas oral contraceptive use and previous weight are not well reported.
Pancreatic adenocarcinoma is one of the deadliest cancers with mortality rates almost equaling incidence rates. Each year, approximately 3,500 Canadians are diagnosed with this disease. Although somewhat inconsistent, epidemiological studies have found that allergies are associated with a reduced pancreas cancer risk while there appears to be no association with asthma. These associations were evaluated in a population-based case-control study conducted in Ontario. Incident cases of pancreatic adenocarcinoma, identified through the Ontario Cancer Registry (OCR), and diagnosed April 1, 2003 to June 1, 2006, were recruited by the Ontario Pancreas Cancer Study (OPCS). Controls were recruited from the Ontario Familial Colorectal Cancer Registry (OFCCR). Data on 276 cases and 378 controls were available for the current study. Multivariable logistic regression analysis was used to obtain age-adjusted odds ratio (AOR) estimates. Ever having allergies or hayfever was associated with reduced pancreas cancer risk (OR = 0.43, 95% confidence interval (CI): 0.29-0.63). There was no association observed between a history of asthma and pancreas cancer risk. Findings are of great importance to understanding the biological mechanisms involved in pancreas cancer development.
Advances in surgical techniques and chemotherapeutic options have expanded indications for surgery in patients with metastatic colorectal cancer. This study aimed to examine how hepatopancreatobiliary (HPB) surgeons approach the management of patients with hepatic colorectal cancer metastases (HCCM).
A web-based survey utilizing 10 clinical scenarios was distributed by e-mail to 37 HPB surgeons in Ontario, Canada. The study region has a population of approximately 13 million people and a universal, single-payer health care system. Descriptive analyses were used to tabulate results.
Twenty-two (59%) surgeons responded to the survey. The majority (19/22, 86%) of respondents favoured neoadjuvant chemotherapy for patients with multiple synchronous and unilobar metastases; only nine of 22 (41%) respondents favoured neoadjuvant chemotherapy for patients with a single synchronous metastasis. In the setting of residual resectable disease following downstaging chemotherapy, 77% (17/22) of surgeons advocated hepatic resection with either radiofrequency ablation (RFA) or wedge resection of the 'ghost' lesions. Over 80% of surgeons would perform a liver and pulmonary resection in a patient with hepatic and multiple unilobar lung metastases. None would offer liver resection to patients with multiple retroperitoneal node involvement, although 55% (12/22) would do so if a single retroperitoneal node was involved. Preoperative portal vein embolization was favoured over RFA in patients with a small metastasis and inadequate functional hepatic volume.
Notable heterogeneity was observed among Ontario's HPB surgeons in approaches to HCCM.
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The MutY human homologue (MYH) gene encodes a member of the base excision repair pathway that is involved in repairing oxidative damage to DNA. Two germline MYH gene mutations that result in Myh proteins containing amino acid substitutions Y165C and G382D (hereafter called the Y165C and G382D mutations) are associated with adenomatous poly-posis and colorectal cancer among patients from several European poly-posis registries. We used a population-based series of 1238 colorectal cancer patients and 1255 healthy control subjects from Ontario, Canada, to examine the risk of colorectal cancer among biallelic and monoallelic germline MYH Y165C and G382D mutation carriers. The entire MYH gene coding region was screened in all MYH Y165C and G382D mutation carriers. Compared with noncarriers, biallelic and monoallelic germline MYH gene mutation carriers had an increased risk of colorectal cancer and were more likely to have first-or second-degree relatives with colorectal cancer (relative risk = 1.54, 95% confidence interval = 1.10 to 2.16). The increased risk of colorectal cancer in biallelic and monoallelic MYH gene mutation carriers was not consistently associated with the development of multiple adenomatous polyps. Loss of heterozygosity in at least one of four loci in MYH was detected in eight (47%) of 17 colorectal tumors from monoallelic MYH gene mutation carriers but in only two (20%) of 10 colorectal tumors from biallelic MYH gene mutation carriers. These two MYH gene mutations may account for a substantial fraction of hereditary colorectal cancer.
Comment In: J Natl Cancer Inst. 2005 Feb 16;97(4):320-1; author reply 321-215713969
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.
Colorectal cancer screening reduces colorectal cancer incidence and mortality. This population-based study was conducted to evaluate (i) the association between subject factors and colorectal screening participation and (ii) the lifetime prevalence of colorectal screening among the general population of Ontario, Canada. Population-based controls were recruited by the Ontario Familial Colorectal Cancer Registry during 1998-2000. The 1944 persons completed an epidemiologic questionnaire. Descriptive statistics were computed and step-wise multivariate logistic regression was used to estimate odds ratios and 95% confidence intervals. Overall, 23% of persons greater than 50 years of age reported ever having had colorectal cancer screening; 17% reported fecal occult blood test (FOBT), 6% sigmoidoscopy, and 4% colonoscopy. Family history of colorectal cancer, increased age, higher household income, and use of hormone replacement therapy (among women) were all significantly associated with ever having had colorectal cancer screening. The low prevalence of colorectal cancer screening among the target population suggests the need for an increased awareness of the public health importance of colorectal cancer screening.
The risk of colorectal cancer associated with smoking is unclear and may be influenced by genetic variation in enzymes that metabolize cigarette carcinogens. The authors examined the colorectal cancer risk associated with smoking and 26 variants in carcinogen metabolism genes in 1,174 colorectal cancer cases and 1,293 population-based controls recruited in Canada by the Ontario Familial Colorectal Cancer Registry from 1997 to 2001. Adjusted odds ratios were calculated by multivariable logistic regression. Smoking for >27 years was associated with a statistically significant increased colorectal cancer risk (adjusted odds ratio (AOR) = 1.25, 95% confidence interval (CI): 1.02, 1.53) in all subjects. Colorectal cancer risk associated with smoking was higher in males for smoking status, duration, and intensity. The CYP1A1-3801-CC (AOR = 0.47, 95% CI: 0.23, 0.94) and CYP2C9-430-CT (AOR = 0.82, 95% CI: 0.68, 0.99) genotypes were associated with decreased risk, and the GSTM1-K173N-CG (AOR = 1.99, 95% CI: 1.21, 3.25) genotype was associated with an increased risk of colorectal cancer. Statistical interactions between smoking and genetic variants were assessed by comparing logistic regression models with and without a multiplicative interaction term. Significant interactions were observed between smoking status and SULT1A1-638 (P = 0.02), NAT2-857 (P = 0.01), and CYP1B1-4390 (P = 0.04) variants and between smoking duration and NAT1-1088 (P = 0.02), SULT1A1-638 (P = 0.04), and NAT1-acetylator (P = 0.03) status. These findings support the hypothesis that prolonged cigarette smoking is associated with increased risk of colorectal cancer and that this risk may be modified by variation in carcinogen metabolism genes.
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Surgical resection of hepatic lesions is associated with intraoperative and postoperative morbidity and mortality. Our center has introduced a laparoscopic liver resection (LLR) program over the past 3 years. Our objective is to describe the initial clinical experience with LLR, including a detailed cost analysis.
We evaluated all LLRs from 2006 to 2010. Each was matched to 2 open cases for number of segments removed, patient age, and background liver histology. Model for End-Stage Liver Disease (MELD) and the Charlson comorbidity index were calculated retrospectively. Nonparametric statistical analysis was used to compare surgical and economic outcomes. Analyses were performed including and excluding converted cases.
Fifty-seven patients underwent attempted LLR. Demographic characteristics were similar between groups. Estimated blood loss was lower in the LLR vs the open liver resection (OLR) group, at 250 mL and 500 mL, respectively (p
During the last 15 years, several single-gene mendelian disorders have been discovered that might account for some of the familial aggregation detected in large population studies of colorectal cancer (CRC). Mutations in DNA mismatch repair (MMR) genes cause hereditary nonpolyposis colorectal cancer-Lynch syndrome, the most common of the recognized CRC-predisposition syndromes, in which one major feature is a young age for cancer onset. However, for young-onset microsatellite stable (MSS) CRC, the familial risk for CRC is unknown.
Patients with CRC who were
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