Smoking, Lower Gastrointestinal Endoscopy, and Risk for Colorectal Cancer
ABSTRACT Background: Lower gastrointestinal (GI) endoscopy can decrease colorectal cancer (CRC) risk strongly through detection and removal of adenomas. Thus, we aimed to investigate whether utilization of lower GI endoscopy modifies the effect of lifetime smoking exposure on CRC risk in a population-based case-control study. Methods: In this study from Southern Germany including 2,916 CRC patients and 3,044 controls, information about lifetime smoking and other risk factors was obtained from standardized interviews. Self-reported endoscopies were validated by medical records. Multivariate logistic regression was performed to investigate associations of smoking with CRC risk after stratification by utilization of lower GI endoscopy in the preceding 10 years. Results: Median age of patients and controls was 69 and 70 years, respectively. Former regular smoking was associated with increased CRC risk in the group with no previous endoscopy (adjusted odds ratio (OR) 1.50, 95% confidence interval 1.28-1.75), whereas no association was found in the group with preceding endoscopy (OR 1.05, 0.83-1.33; p for interaction <0.01). Lower GI endoscopy did not modify the association of smoking and CRC risk among current smokers and among the more recent quitters. Conclusions: Our results suggest that the increased risk of CRC among former regular smokers is essentially overcome by detection and removal of adenomas at lower GI endoscopy. However, risk of CRC was increased if smoking was continued into higher adult age. Impact: The strong protective effect of lower GI endoscopy may be compromised by continued smoking. Smoking cessation may increase the efficacy of lower GI endoscopy.
SourceAvailable from: PubMed Central[Show abstract] [Hide abstract]
ABSTRACT: Background The xeroderma pigmentosum complementary group D (XPD) gene has been linked to the development of colorectal cancer (CRC) through disruption of DNA repair. Several studies have suggested that the XPD polymorphism Lys751Gln is associated with an increased risk of developing CRC. However, previous results remain inconclusive. Herein, we performed a meta-analysis to evaluate the potential for this relationship. Methods Relevant studies were retrieved from the PubMed database. Strict selection and exclusion criteria were determined, and the odds ratio with a 95% confidence interval was used to assess the strength of associations. The fixed or random effects model was selected on the basis of heterogeneity tests among studies. Publication bias was estimated using funnel plots and Egger’s regression test. Results The meta-analysis included 2,961 cases and 4,539 controls from eleven studies. The results indicated that the XPD Lys751Gln polymorphism had no association with CRC risk for all genetic models (Gln-Gln versus Lys-Lys, P=0.477; Lys-Gln versus Lys-Lys, P=0.283; Lys-Gln + Gln-Gln versus Lys-Lys, P=0.562), even when compared within subgroups based on ethnicity and source of controls. Conclusion Based on the results of our meta-analysis, there is no evidence of a link between the XPD Lys751Gln polymorphism and risk of CRC.OncoTargets and Therapy 07/2014; 7:1255-60. DOI:10.2147/OTT.S66291 · 1.34 Impact Factor
[Show abstract] [Hide abstract]
ABSTRACT: Because advances in therapy have increased long-term survival for women with cervical cancer, it is important to study the risk of secondary primary malignancies in high-dose organ areas. From the 1973-2009 National Cancer Institute Surveillance, Epidemiology, and End Results (SEER) program, we studied the risk of developing cancer of the colon and rectum in 64,507 cervical cancer patients over 35 years after initial radiation treatment. We also assessed change in risk over time. Kaplan-Meier estimator for survival curve and Cox proportional hazards models was used. More than half (52.6 %) of the cervical cancer patients received radiation treatment. In the analyses adjusted for race/ethnicity, age, marital status, surgery status, stage and grade, the risk of colon cancer between those both with and without XRT diverged beginning at approximately 8 years. After 8 years, the hazard ratio for developing colon cancer was 2.00 (95 % CI 1.43-2.80) for women with radiation versus those without radiation treatment. The risk of rectal cancer diverged after 15 years of follow-up (HR 4.04, 95 % CI 2.08-7.86). After 35 years of follow-up, the absolute risk of developing colon cancer was 6.5 % for those who received radiation versus 2.5 % for those without, and 3.7 versus 0.8 % for rectum. The risk of colon and rectum cancer over 20 years of follow-up after radiation remained the same across three eras (1973-1980, 1981-1990, and 1991-2000). Radiation-induced second cancers of the colon and rectum may occur 8 years after radiation treatment for cervical cancer.Medical Oncology 05/2014; 31(5):943. DOI:10.1007/s12032-014-0943-2 · 2.06 Impact Factor