Oral contraceptives and breast cancer: a cooperative Italian study.
La Vecchia C, Negri E, Franceschi S, +7 more·International journal of cancer
The relationship between oral contraceptives (OC) and breast-cancer risk was analysed using data from a case-control study conducted between June 1991 and February 1994 in 6 Italian centres on 1,991 patients below age 65 with histologically confirmed incident breast cancer and 1,899 controls admitted to hospital for a…