Risk factors cannot explain the higher prevalence rates of precancerous colorectal lesions in men.

BACKGROUND: Prevalence of (pre)cancerous colorectal lesions are higher in men than in women, although transition rates from advanced lesions to cancer is similar in both sexes. Our aim was to investigate whether the sex-specific difference in incidence of premalignant colorectal lesions might be explained by the impact of risk factors. METHODS: A cross-sectional study analysing health check-up examinations and screening colonoscopies performed within a national quality assurance program. RESULTS: A total of 25 409 patients were included in this study, 50.8% were women. Median age for both sexes was 60 years (interquartile range (IQR) 54-67). A multivariable model showed that risk factors mediated only 0.6 of the 10.4% gender gap in adenoma and 0.47 of the 3.2% gender gap in advanced adenoma detection rate. Smoking was the only independent risk factor with a varying sex-specific effect (men OR 1.46, CI 1.29, 1.64, women OR 1.76, CI 1.53, 2.06) and advanced adenomas (men OR 1.06, CI 0.80-1.42; women OR 2.08, CI 1.52-2.83). Independent risk factors for adenomas were BMI (OR 1.35 per IQR, CI 1.25-1.47) and triglyceride level (OR 1.03 per IQR, CI 1.00-1.06); for advanced adenomas physical activity (none vs regular: OR 1.54, CI 1.18-2.00, occasional vs regular: OR 1.17, CI 1.00-1.38), cholesterol level (OR 1.13 per IQR, CI 1.02-1.25), blood glucose level (OR 1.05 per IQR, CI 1.01-1.09) and alcohol score (OR 1.09 per IQR, CI 1.01-1.18). CONCLUSIONS: Risk factors cannot explain higher prevalence rates in men. Results of this study strongly underline the need for sex-specific screening recommendations.

Trends in quality of screening colonoscopy in Austria.

Background and study aim: Screening colonoscopy only effectively prevents colorectal cancer if performed with high quality. The aim of this study was to analyze the detection rates of premalignant colorectal lesions in screening colonoscopies performed within a nationwide quality control program for screening colonoscopy in Austria. Methods: Data from electronic records of the screening program from its implementation in 2007 until December 2014 were analyzed in order to calculate detection rates for adenomas, advanced adenomas, polyps, and proximal lesions, and rates of cecal intubation, sedation, complications, and adequate bowel preparation. Results were evaluated to identify trends and changes in quality parameters over the 8-year study period. Results: During the study period, 301 endoscopists provided data from 159 246 screening colonoscopies. Mean age of screened individuals was 61.1 years, and 49.1 % were women. Significant increases over time were found for age- and sex-adjusted adenoma detection rates (ADRs), which increased from a mean of 22.2 % (SD 10.7 %) in 2007/2008 to 24.2 % (SD 11.6 %) in 2013/2014. On average, each endoscopist increased their individual ADR by + 1.5 percentage points per 2-year period (95 % confidence interval [CI] 0.9 - 2.2 percentage points; P < 0.01). Similarly, detection rates for proximal lesions rose from 15.8 % (SD 9.8 %) to 21.7 % (SD 13.3 %  + 2.5 percentage points per 2-year period, 95 %CI 1.9 - 3.1 percentage points; P < 0.01). ADR in men increased from 27.6 % in 2007/2008 (SD 11.1 %) to 29.2 % in 2013/2014 (SD 12.7 %; P < 0.01); ADR in women increased from 14.2 % (SD 7.1 %) in 2007/2008 to 19.0 % (SD 10.5 %) in 2013/2014 (P < 0.01). Advanced adenoma detection rates decreased during the study period, from 11.4 % (SD 9.0 %) in 2007/2008 to 7.6 % (SD 5.4 %) in 2013/2014 (P = 0.06) in men, and from 5.5 % (SD 5.3 %) in 2007/2008 to 4.0 % (SD 4.1 %) in 2013/2014 in women (P = 0.21). Conclusions: This study showed an improvement in the quality of screening colonoscopies performed within a quality assurance program in Austria between 2007 and 2014. Although, overall ADR increased significantly during the study period, there was a decrease in the rate of advanced adenoma detection.

Sex is a stronger predictor of colorectal adenoma and advanced adenoma than fecal occult blood test.

Due to high costs and limited availability of screening colonoscopy, some screening programs require a positive fecal occult blood test (FOBT) before screening colonoscopy is remunerated. As male sex is a strong predictor of adenoma and advanced adenoma, we evaluated whether a positive FOBT or male sex is a stronger risk factor for adenoma and advanced adenoma. FOBT and screening colonoscopy results from 18.665 consecutive patients participating in a "national health check program" between 2009 and 2011 were included in this cohort study. Age-corrected adenoma detection rates (ADR), advanced adenoma detection rates (AADR) and carcinoma detection rates were calculated for men and women according to FOBT result separately. ADR and AADR in FOBT-positive men (34.6 and 11.8 %) and FOBT-negative men (29.1 and 7.6 %) were higher than ADR and AADR in FOBT-positive women (20 and 6.9 %) and in FOBT-negative women (17.6 and 4.4 %), (p = 0.0003). Men with negative FOBT were at higher risk of having an adenoma and advanced adenoma than women with positive FOBT (p < 0.0001). Odds ratios of a positive FOBT for ADR and AADR were 1.3 (1.1-1.5) (p = 0.0047) and 1.6 (1.2-2.1) (p < 0.0001), respectively. Odds ratios of male sex to predict ADR and AADR were significantly higher with 1.9 (1.8-2.1) and 1.8 (1.6-2), respectively (p < 0.001). Male sex is a stronger predictor for colorectal adenoma and advanced adenoma than positive FOBT. These results should be taken into account analyzing FOBT-based screening programs.