Oral contraceptive use has no adverse effect on the prognosis of breast cancer

This study evaluates the possible effect of OC use on the prognosis of established breast cancer. Three hundred forty-seven patients with primary invasive breast carcinoma age 50 and under treated from 1971 to 1981 are included in this study. There were 112 OC Users (U) and 235 Non-Users (NU). Separate retrospective analysis were done for a group of 154 patients (59 U and 95 NU) under age 35 (Group A) and for 193 patients (53 U and 140 NU) age 35 to 50 (Group B), in order to pay particular attention to relationship of duration, recency and latency of OC usage. Both subsets of U and NU presented similar clinical characteristics regarding menstrual, reproductive, family history, histology, receptor status. Users presented with a similar extent of disease as Non-Users. No significant differences were found between U and NU in disease-free interval (Gr A p = .41; Gr B p = .81), metastatic period (Gr A p = .66; Gr B p = .41) or survival (Gr A p = .54; Gr B p = .79), either alone or when adjusted for extent of node involvement. Users of less than two years (78 patients) had a similar survival (Gr A = .54; Gr B p = .36) as those of longer duration (33 patients). Recent OC users within a year of diagnosis had a similar survival as other users who stopped the pills more than one year (Gr A p = .86; Gr B p = .14). No significant differences were noticed in survival between the patients who began the use 10 years or more before diagnosis from those beginning more recently (Gr A p = .82; Gr B p = .69). Our data suggests no adverse effect of OC on the outcome of breast cancer, regardless the duration of use, latency or recency period.