Colon cancer screening practices following genetic testing for hereditary nonpolyposis colon cancer (HNPCC) mutations.

BACKGROUND: Although increased colonoscopic surveillance is recommended for hereditary nonpolyposis colon cancer (HNPCC) mutation carriers, limited information is available on adherence to colorectal cancer screening recommendations. This study investigated colonoscopy practices following genetic testing for HNPCC mutations. METHODS: This prospective cohort study was conducted between May 22, 1996, and November 13, 1999. Participants were 98 men and women without a personal history of colon cancer or colectomy who were identified from 11 extended HNPCC families. Colonoscopy use was evaluated by telephone before genetic counseling and was reassessed 1, 6, and 12 months following test results disclosure. RESULTS: During the 12 months following genetic counseling and testing, 73% (16/22) of HNPCC mutation carriers, 16% (8/49) of noncarriers, and 22% (6/27) of decliners reported having a colonoscopy (chi(2) = 23.97, P<.001). After controlling for clinical factors and pretest screening practices, HNPCC mutation carriers were significantly more likely than test decliners to have a colonoscopy (odds ratio [OR], 12.12; 95% confidence interval [CI], 3.42-42.96; P<.001). There were no differences in colonoscopy use between noncarriers and decliners (OR, 0.60; 95% CI, 0.28-1.29; P =.19). Perceived control over developing colon cancer also had a significant effect on posttest colonoscopy use (OR, 2.19; 95% CI, 1.22-3.94; P =.01). CONCLUSIONS: Genetic testing may motivate increased colonoscopic screening among HNPCC mutation carriers. Increased efforts may be needed to assess patients' family histories of colon cancer and provide appropriate referrals for genetic counseling and testing to target colonoscopic screening to high-risk individuals.

Individual differences in nicotine intake per cigarette.

The increase in levels of blood nicotine that occurs from smoking a single cigarette, sometimes referred to as a "nicotine boost," is an individualized measure of how much nicotine has been extracted from smoking a cigarette. This study investigated the demographic, smoking status, and psychological predictors of nicotine boost in a sample of 190 treatment-seeking smokers. Boost was assessed by comparing plasma nicotine levels before and after participants smoked one of their own brand cigarettes ad libitum. Positive affect (mood) was a significant positive predictor of nicotine boost, controlling for baseline cotinine levels and cigarette brand (Federal Trade Commission) nicotine delivery. However the proportion of variability accounted for in the model was relatively small (5%). Future research on individual differences in nicotine boost is warranted to clarify the role of psychological, physiological, and cigarette-related determinants.

Effects of dopamine transporter and receptor polymorphisms on smoking cessation in a bupropion clinical trial.

This study examined the role of dopaminergic genes in prospective smoking cessation and response to bupropion treatment in a placebo-controlled clinical trial. Smokers of European ancestry (N=418) provided blood samples for genetic analysis and received either bupropion or placebo (10 weeks) plus counseling. Assessments included the dopamine D2 receptor (DRD2) genotype, dopamine transporter (SLC6A3) genotype, demographic factors, and nicotine dependence. Smoking status was verified at the end of treatment (EOT) and at 6-month follow-up. The results provided evidence for a significant DRD2 * SLC6A3 interaction effect on prolonged smoking abstinence and time to relapse at EOT, independent of treatment condition. Such effects were no longer significant at 6-month follow-up, however. These results provide the first evidence from a prospective clinical trial that genes that alter dopamine function may influence smoking cessation and relapse during the treatment phase.

Predictors of attendance in a randomized clinical trial of nicotine replacement therapy with behavioral counseling.

Participant attendance at smoking cessation-counseling sessions is an important factor in treatment outcome. In this study, we examined the influence of demographic, psychological, and smoking history variables on attendance at a randomized clinical trial comparing transdermal nicotine and nicotine nasal spray that included seven sessions of behavioral group counseling. Of the 353 participants, 70.5% attended all seven sessions. Perfect attendance predicted abstinence from cigarettes at the end of treatment and at 6-month follow-up. In a logistic regression model, higher levels of education and higher body mass index were significant independent predictors of better attendance. There was a significant interaction between type of nicotine replacement (transdermal nicotine vs. nasal spray) and sex: females were less likely than males to have perfect attendance in the nasal spray group, but there was no sex difference in attendance for the transdermal nicotine group. These findings suggest that smokers with lower body mass index and less formal education may benefit from proactive counseling to address individual barriers to attendance at smoking cessation counseling. Additional research in this area would also be valuable to evaluate strategies to promote attendance in these high-risk groups.