A Case-control Study of the Relationships between Reproductive Factors and Degree of Dysplasia of the Colorectal Adenoma and Cancer

Lee, Se Young; Lee, Won Chul; Choi, Kyu Yong; Kim, Mi Kyung; Lee, Jin Hee; Meng, Kwang Ho

Abstract

OBJECTIVES
Evidence for an effect of reproductive factors on colorectal carcinogenesis is not yet consistent. Little research has been conducted to investigate whether reproductive factors were associated with colorectal adenomas that are the precursors of colorectal cancer. We evaluated the relationships between reproductive factors and the degree of dysplasia of the colorectal adenoma and cancer as colorectal adenoma-carcinoma sequence. METHODS: For this study, 241 adenoma cases with histo-pathologically confirmed incident colorectal adenoma, 76 cancer cases with colorectal cancer and 1677 controls were collected from Our Lady of Mercy Hospital, The Catholic University of Korea, during 1994-1999. Before colonoscopy, information on demographic characteristics, reproductive factors, life style habits and dietary intake were obtained by interviewed questionnaire. Adjusted OR and 95% CI were estimated by using polytomous logistic regression model. Potential confounders that were selected based on the goodness of fit statistics and interaction between risk factors were considered in this adjustment. The Wald statistic was calculated to test the heterogeneity of the odds ratios for each case. RESULTS: Postmenopausal women with natural menopause were found to be positively associated with the risk of mild dysplasia adenoma (multivariate-adjusted OR : 2.59, 95% CI=1.1-6.2). Parity was found to be negatively associated with the risk of colorectal cancer (age-adjusted OR : 0.40, 95% CI=0.2-0.9), but did not significantly decrease the risk of colorectal cancer (multivariate-adjusted OR : 0.95, 95% CI=0.3-2.9). No associations were seen between age at menarche, breast feeding, induced abortion, oral contraceptive use, menopausal types, menopausal age or hormone replacement therapy (HRT) and the degree of dysplasia of the colorectal adenoma and cancer. However, none of these associations differed significantly between the degree of dysplasia of the colorectal adenoma and cancer. CONCLUSIONS: These findings suggest that postmenopausal women with natural menopause may experience increased risk of mild dysplasia adenoma among colorectal adenoma-carcinoma sequence.