Sex hormones and risk of lung and colorectal cancers in women: a Mendelian randomization study.

The roles of sex hormones such as estradiol, testosterone, and sex hormone-binding globulin (SHBG) in the etiology of lung and colorectal cancers in women, among the most common cancers after breast cancer, are unclear. This Mendelian randomization (MR) study evaluated such potential causal associations in women of European ancestry. We used summary statistics data from genome-wide association studies (GWASs) on sex hormones and from the Trøndelag Health (HUNT) Study and large consortia on cancers. There was suggestive evidence of genetically predicted 1-standard deviation increase in total testosterone levels being associated with a lower risk of lung non-adenocarcinoma (hazard ratio (HR) 0.60, 95% CI 0.37-0.98) in the HUNT Study. However, this was not confirmed by using data from a larger consortium. In general, we did not find convincing evidence to support a causal role of sex hormones on risk of lung and colorectal cancers in women of European ancestry.

To Screen or Not to Screen Adults 45-49 Years of Age: That is the Question.

Should we adopt the recently published American Cancer Society (ACS) recommendations to screen adults at 45 years of age? The main reasons for adopting the recommendation include the increase of colorectal cancer (CRC) in the young, especially late-stage tumors. Screening at 45 years is also supported by predictive modeling, which the ACS employed using updated and improved models as compared to those previously used by the United States Preventive Services Task Force. Reasons against adopting include concerns with the models as well as diversion of scarce screening resources away from high-risk populations. Readers are provided with opposing viewpoints regarding the ACS recommendation.

Screening rates for colorectal cancer in Canada: a cross-sectional study.

INTRODUCTION: Implementation of population-based colorectal cancer (CRC) screening programs should reduce disparities in participation in CRC screening. We estimated CRC screening rates in 2012 in Canada and assessed predictors of screening in provinces with and without well-established population-based screening programs. METHODS: We used data from the Canadian Community Health Survey for 2012 to calculate the prevalence of up-to-date CRC screening, defined as fecal occult blood testing (FOBT) within 2 years before the survey or flexible sigmoidoscopy or colonoscopy within 10 years before the survey, or both. Weighted proportions of individuals with up-to-date screening were calculated and logistic regression analysis performed to assess predictors of up-to-date CRC screening, including differences in participation by income level. RESULTS: The prevalence of up-to-date CRC screening among people 50-74 years of age in 2012 was 55.2%, ranging from 41.3% in the territories to 67.2% in the province of Manitoba. The rate for sigmoidoscopy or colonoscopy was 37.2% (highest in Ontario, at 43.3%), and for FOBT it was 30.1% (highest in Manitoba, at 51.7%). About 41% of those who had an FOBT also had a sigmoidoscopy or colonoscopy. Individuals in the highest income group were more likely than those in lower-income groups to be up to date with CRC screening, even in provinces with well-established population-based screening programs. INTERPRETATION: More than half of Canadians were up to date with CRC screening in 2012, but there were large differences among provinces. Differences by income group in provinces with population-based screening programs need particular attention.