Breast cancer in the Thai Cohort Study: An exploratory case-control analysis

Abstract

Breast cancer incidence may be increasing in Thailand but very little research has assessed core breast cancer risk factors in this country. We used baseline questionnaire data from a national cohort study of Thai Open University students in an exploratory case-control study of breast cancer. The study included 43 female cases and 860 age-matched controls selected from the remaining 47,271 female cohort participants. Odds ratios and 95% confidence intervals were calculated using conditional logistic regression. The women were predominantly premenopausal. Taller women had an increased risk of breast cancer (OR = 2.3, 95% CI 1.1-4.8, for height ≥160 cm vs ≤154 cm) as did women with non-insulin dependent diabetes mellitus (OR = 8.4, 95% CI 1.7-41). Women with older siblings had a reduced risk of breast cancer compared to those firstborn (OR = 0.3, 95% CI0.2-0.7). Although limited by small case numbers, our findings suggest substantial increases in breast cancer rates in Thailand could be expected in the future. © 2009 Elsevier Ltd. All rights reserved.