Cyclical mastalgia as a marker of breast cancer susceptibility: results of a case-control study among French women.

A matched case-control study in a population of urban, non-menopaused women living in Paris was performed between 1983 and 1985 to investigate the risk of breast cancer (BC) in relation to various factors with a particular interest in the effect of the use of oral contraceptive (OC) and the existence of cyclical mastalgia (CM). Two hundred and ten non-menopaused women, less than 45 years old, with newly diagnosed BC were compared to 210 controls from the same geographic area matched on year of birth, age, education level and age at first full term pregnancy (FFTP), when justified. The adjusted Relative Risk of BC (RRa) was significantly increased for a total duration of OC use longer than 72 months (RRa 2.80; 95% CI 1.56-5.01), as well as the RRa for OC use above 48 months before FFTP (3.26 95% CI 1.37-7.76) and, to a lesser extent, the RRa for OC use above 48 months after FFTP (2.02 95% CI 1.07-3.84) respectively. Adjustment was performed on familial history of BC, personal history of Benign Breast Disease (BBD), age at menarche. A previous history of cyclical mastalgia was found to be associated with an increased risk of BC. The significant increase remained after adjustment on the previously mentioned confounding factors and OC use: RRa 2.12; 95% CI (1.31-3.43). Under a precise definition related to the hormonal environment, mastalgia appear to be an interesting marker of breast cell susceptibility, the importance of which can only be validated by prospective studies.