Colorectal cancer in middle-aged women in relation to hormonal status: A report from the Women's Health in the Lund Area (WHILA) study

Abstract

Objective. To delineate a perceived association of estradiol versus estradiol plus norethisterone hormone therapy on the prevalence of colorectal cancer in postmenopausal women.Methods. The Women's Health in the Lund Area (WHILA) project covers 10 766 women aged 50–60 years, living in the Lund area, Sweden. Out of this population, 6908 (64%) women completed questionnaires, underwent physical and laboratory assessments and had self-reported information regarding colorectal cancer. Four hundred and twenty-two (6%) were premenopausal (PM), 3600 (52%) were postmenopausal without hormone therapy (PM0), 2452 (36%) were postmenopausal with combined hormone therapy (PMT-HT) and 364 (5%) were postmenopausal with estrogen monotherapy (PMT-E).Results. There were 21 cases of colorectal cancer (0.3%), one in the PM group, 16 in the PM0 group, two in the PMT-HT group and another two in the PMT-E group. Colorectal cancer prevalence was lower in the PMT-HT than in the PM0 group (odds ratio (OR) = 0.18, 95% confidence interval (CI) = 0.04–0.80). However, for the PMT-E group, the OR (95% CI) was 1.02 (0.86–1.20). There was a positive association between low physical activity (p = 0.04), low parity (p = 0.02) and risk of colorectal cancer.Conclusion. Combined hormone therapy seemed to be associated with a lower risk of colorectal cancer in postmenopausal women in contrast to estrogen monotherapy. Hence the progestin might have a protective role.