The survival of 193 premenopausal breast cancer patients was investigated in relation to their history of early use of oral contraceptives. The women were born in 1939 or later and diagnosed in the southern health care region of Sweden. Women, who had started their oral contraceptive use (OC-use) before 20 years of age had a significantly lower survival rate as compared with those who had never used OC and late users (p = 0.02 and = 0.04 respectively, generalized Wilcoxon test). For women who started OC-use between 20 to 25 years of age, a tendency for a shorter survival was seen in comparison with women who had never used OC (p = 0.18). For all patients simultaneously, the relative risk adjusted for age at diagnosis increased for earlier OC-start. When only stages II and III were considered in a stratified multivariate model, a significantly elevated risk was seen for early users of OC irrespective of age or of adjuvant treatment given. The estrogen and progesterone receptor concentrations of the primary tumor were significantly lower among early users (p = 0.001 and p = 0.05 respectively).
PIP: The survival of 193 premenopausal breast cancer patients was analyzed in terms of onset of use of oral contraceptives: earlier use of pills predicted shorter survival times. 193 consecutive breast cancer premenopausal patients, from the southern region of Sweden diagnosed at University of Lund, were staged and interviewed for age when starting pills, duration, and brand. Women who started orals before age 20 had significantly shorter survival rates than never-users or late users (p=0.02 and 0.04). Women who started orals between 20-25 years of age showed a tendency toward shorter survival compared to never users (p=0.18). The relative risks, adjusted for age at diagnosis, increased in proportion to earlier age of onset of pill use (never = 1.0; 25 = 0.7; 20-25 = 2.8; 20 = 9.2). When only cancer stages II and II were considered in a multivariate model, a significantly elevated risk appeared for early users regardless of age or treatment given. The estrogen and progesterone receptor concentrations in the primary tumor were significantly lower among early users (p=0.001 and 0.05). These findings are consistent with previously reported larger tumor size, higher frequency of axillary metastases and altered hormone receptor status in early pill users.