Objectives: Early detection of cancer incidence and tobacco control are prioritized in the second-term of the Basic Plan for Promotion of Cancer Measures. However, the cancer screening rate is low and smoking prevalence high in Japan. Smokers may not participate in cancer screening, although they are a high-risk population for cancer mortality. This study examined whether smoking status, including number of cigarettes smoked per day and the Brinkman index (BI), was associated with participation in screening for lung, gastric, and colorectal cancers.
Methods: In 2011, we conducted a cross-sectional study in Osaka city: 2,016 subjects aged 40 to 64 (men, N=966; women, N=1,050) were analyzed (response rate=52.4%). We used multivariable logistic regression with stratification by sex to calculate odds ratios (ORs) for participation in screening for lung, gastric, and colorectal cancers according to smoking status, such as number of cigarettes smoked per day and the BI.
Results: Compared with non-current smokers, current smokers were less likely to participate in all cancer screenings. Men who currently smoke had significantly lower odds for gastric and colorectal cancer screening participation than non-current smokers (gastric : OR=0.71, P=0.036 ; colorectal : OR=0.67, P=0.012). Furthermore, compared with non-current smokers, men who smoked more than 20 cigarettes per day had significantly lower odds for all cancer screenings (lung: OR=0.61, P=0.009; gastric: OR=0.61, P=0.009; colorectal: OR=0.59, P=0.004). Similar results were observed in smokers with a BI≧600 (lung: OR=0.55, P=0.006; gastric: OR=0.62, P=0.028; colorectal: OR=0.56, P=0.006). Among the women, significant associations between number of cigarettes smoked per day, BI, and colorectal cancer screening participation were observed (more than 20 cigarettes per day: OR=0.39, P=0.004; BI≧400: OR=0.51, P=0.020).
Conclusion: Current smokers were less likely to undergo cancer screening compared with non-current smokers. These associations were stronger in men with greater numbers of cigarettes smoked per day and a higher BI score. Because smokers do not receive cancer screening, they may be at higher risk for cancer mortality. Counseling at the chance of cancer screening should be considered as a good opportunity to provide useful information on smoking cessation, as well as to promote cancer screening participation.