CYCLICAL MASTOPATHY AND PREMENOPAUSAL BREAST-CANCER RISK - RESULTS OFA CASE-CONTROL STUDY

Cyclical mastopathy (CM) is a common clinical syndrome of premenstrual breast swelling and tenderness. Its symptoms are relieved by reductio n in dietary fat intake and, because fat intake may be associated with breast cancer risk, it was hypothesized that CM may also be related t o breast cancer risk. This case-control study included 192 premenopaus al women with a recent history of axillary node-negative breast cancer and 192 age-matched premenopausal controls. Subjects provided informa tion on diet and risk factors, and they recorded breast symptoms prosp ectively during one menstrual cycle. Symptoms in the noncancerous brea st of cases and the matched (right or left) breast of controls were ex amined. A cyclical pattern of symptoms was identified in both groups; breast tenderness scores were similar post-menstrually (p = 0.31) but were significantly higher premenstrually in the case group (p = 0.03). Cases also had a greater premenstrual increase in breast tenderness t han controls (p = 0.03). When the effects of other risk factors for br east cancer were included in multivariate analyses, the association of cyclical tenderness with breast cancer persisted (p = 0.05), the odds ratio for severe tenderness being 3.32. Thus, we have identified an a ssociation of cyclical breast tenderness with breast cancer risk in pr emenopausal women. The association persists after consideration of die t and the effects of other breast cancer risk factors.