Cancer screening among the overweight and obese in Canada

Abstract

Background: Despite increased cancer incidence and mortality among overweight and obese men and women, U.S. studies have reported the reduced use of cancer screening among these subjects. We sought to analyze the relationship between overweight/obesity and cancer screening practices using population-based Canadian data.

Methods: Responses from adults surveyed in the Canadian Community Health Survey 2003 who provided complete information regarding variables of interest were analyzed. Cancer screening modalities included Pap smear testing, mammography, and fecal occult blood testing, and were based on contemporary recommendations of the Canadian Task Force for Preventive Health. The association between overweight/obesity and cancer screening was explored using logistic regression after adjusting for demographic and socioeconomic factors, health habits, healthcare access, and obesity-related comorbidity. The analysis was conducted in 2007.

Results: Compared to normal-weight controls, overweight and obese women were significantly less likely to have undergone cervical cancer screening. In the fully adjusted model, increasing obesity was associated with decreasing odds of Pap smear testing, with overweight, Class-I, -II, and -III obesity having 95% ORs of 0.87 (0.81, 0.94); 0.79 (0.72, 0.88); 0.62 (0.54, 0.71); and 0.61 (0.53, 0.72), respectively. The prevalence of biennial breast and colorectal cancer screenings was largely unaffected by weight in the adjusted analyses.

Conclusions: Overweight and obesity are associated with markedly lower utilization of cervical cancer screening, despite increased disease risks. This association is independent of sociodemographic factors, comorbidity, and healthcare access. This is consistent with findings in U.S. populations, and suggests that patient and provider factors serve as greater barriers to screening than do healthcare system factors.