Underuse of colorectal cancer screening among men screened for prostate cancer: a teachable moment?

Prostate cancer (PCa) and colorectal cancer (CRC) are the second and third leading causes of cancer death, respectively.1 Although substantial evidence suggests that CRC screening is effective in reducing disease-related mortality,2-7 the effectiveness of PCa screening remains uncertain.8,9 As a result, CRC screening is widely recommended by all major medical organizations.4,6,10 However, for PCa screening, the US Preventive Services Task Force has stated that there is not enough evidence to make a recommendation for or against PCa screening for men younger than 75 years, and that physicians and patients should make a shared decision.11 Despite these differences in evidence and in recommendations, adherence rates are very similar, with about ½ of age-eligible US men adherent to PCa screening1 and to CRC screening.12-15 The 2006 Behavioral Risk Factors Surveillance System reported that 61.5% of men aged 50 years or older in the United States were adherent to CRC screening,13 and 55.4% of men aged 50 year and older had had a prostate-specific antigen (PSA) blood test in the past year.4 Several studies have assessed the predictors of CRC screening, reporting that higher education,16-27 a usual source of care,12,16,19-26 a physician recommendation,17,23,28,29 being insured,12,16,19,22-24,26-28,30 a higher income,16,18,19,22,24,27,30 exercise and other positive health behaviors,16,19,26,27 older age,16,19,21,23,25-27 and a recent PSA test12,21,23,25,31 are all positively associated with CRC screening. There have been conflicting results regarding CRC screening adherence and self-reported health status,12,17,19,20 as well as among former smokers,18,23,26 although current smoking has consistently predicted lower CRC screening adherence.16,26,30 There have also been conflicting findings regarding race differences for CRC screening, with some studies showing no race differences,16,25,27 others showing lower adherence among African Americans,20,32 and 1 study showing higher adherence among African American men.12 Possible explanations for these conflicting findings include demographic differences in the samples studied, such as different ages20 or socioeconomic status (SES) levels. Given the racial disparities in incidence and mortality of CRC,33,34 it is particularly important to understand the impact of race and related factors on CRC screening behaviors. Among a sample of men who had registered to undergo free PCa screening, we assessed the rates and sociodemographic correlates of prior CRC screening. The primary goal of this study was to determine whether free PCa screening programs, at which over 100,000 US men are screened each year,35 might provide access to a large and easily accessible group of men who are aware of cancer early detection, but who are perhaps unaware of or nonadherent to CRC screening recommendations. Given the differences in cost, invasiveness, and preparation for screening of these 2 cancers, we evaluated whether a portion of men attending free PCa screening were eligible for but nonadherent to CRC screening, suggesting that PCa screening sites could serve as a teachable moment12,36 for CRC screening education.