Basal cell carcinoma and anthropometric factors in the U.S. radiologic technologists cohort study.

Basal cell carcinoma (BCC) is the most common cancer in Caucasian populations. Although several risk factors are well-established, including ultraviolet radiation (UVR) sensitivity and exposure, few studies have examined anthropometric measures and BCC. Using Cox proportional hazards regression analysis, we prospectively investigated the relationship between height, weight and body mass index (BMI) and BCC in 58,213 Caucasian participants (11,631 men and 46,582 women) from the United States Radiological Technologists cohort. This analysis was limited to participants who were cancer-free at baseline. The baseline questionnaire provided self-reported anthropometric factors and the subsequent questionnaire collected skin cancer susceptibility factors, lifetime UVR exposure derived from residential and personal UVR exposure (time outdoors) and health outcomes. During 509,465 person-years of follow-up, we identified 2,291 BCC cases (486 men; 1,805 women). BCC risk increased with increasing height, and decreased with increasing weight and BMI in both sexes, even after adjusting for UVR susceptibility factors and exposures. For BMI categories: <25 (reference); 25-<30; 30-<35 and ≥ 35 kg m(-2) , multivariate hazard ratios (HR) in women were: 1.00; 0.74 (95% CI = 0.66-0.83); 0.67 (0.56-0.81) and 0.57 (0.44-0.74), respectively, p-trend ≤ 0.0001. Risks were similar in men. The inverse association between BMI and BCC was unaffected by controlling for sun-related exposures. Nevertheless, it may at least partly reflect residual UVR confounding. Further research with more detailed sun exposure data, including clothing patterns, would help clarify the relationship between BMI and BCC.