Search

INTRODUCTION Recent epidemiological studies have reported an inverse association between sun exposure and Non-Hodgkin lymphoma (NHL) which may be related to vitamin D or other factors, but these studies have been conducted almost exclusively in the Western countries, and in temperate locations. METHODS The Singapore Lymphoma Study is a hospital-based, case-control study conducted in Singapore between Feb 2005 and Dec 2008. Singapore residents (men and women, ethnic Chinese/Malays/Indians) aged 18 to 90 formed the study population. Detailed information on outdoor activities under sun (for recreational or occupational purposes) during childhood and in adulthood, skin colour and sun sensitivity, and other information on other possible risk factors were collected in personal interviews. A total of 543 incident malignant lymphomas including 74 Hodgkin's lymphoma (HL), 403 B-cell and 61 T and NK-cell NHL and 5 others, and 830 controls were recruited. Odds ratios (OR) and 95% confidence intervals (CI) were calculated using unconditional logistic regression analysis, adjusted for age, gender, ethnicity, and housing types as surrogate for social economic status. RESULTS Skin colour and sun sensitivity did not show any association with risk of malignant lymphoma, after adjusting for ethnicity. We observed a reduced overall risk of NHL (but not HL) among subjects who reported spending time outdoors regularly, especially on weekends/rest days. A lower risk of NHL was associated with recreational sun exposure in childhood non-school days (OR 0.7, 95% CI 0.5-0.9) and in adulthood weekends/rest days (OR 0.8, 95%CI 0.6-1.0), and the observed association was significant in females when stratified by gender. In addition, occupational sun exposure in males was inversely associated with the risk of NHL (OR 0.7, 95%CI 0.5-1.0). Cumulative working time outside under sun appeared unrelated to NHL overall. The associations were more consistently observed in B-cell NHL subtypes (OR 0.6, 95%CI 0.5-0.8), in diffuse large B-cell lymphoma (OR 0.6, 95%CI 0.5-0.9) and mucosal-associated lymphoid tissue lymphoma (OR 0.5, 95%CI 0.2-1.0), than in T-cell NHL. CONCLUSION As the first case-control lymphoma study in Asia, our data are consistent with an inverse association between intermittent sun exposure and NHL in this study population. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1824.