Effect of Pregnancy on Overall Survival After the Diagnosis of Early-Stage Breast Cancer

Abstract

PURPOSE: To evaluate the impact of subsequent pregnancy on the prognosis of patients with early breast cancer. PATIENTS AND METHODS: One hundred eight patients who became pregnant after diagnosis of early-stage breast cancer were identified in institutions participating in International Breast Cancer Study Group (IBCSG) studies. Fourteen had relapse of breast cancer before their first subsequent pregnancy. The remaining 94 patients (including eight who relapsed during pregnancy) formed the study group reported here. A comparison group of 188 was obtained by randomly selecting two patients, matched for nodal status, tumor size, age, and year of diagnosis from the IBCSG database, who were free of relapse for at least as long as the time between breast cancer diagnosis and completion of pregnancy for each pregnant patient. Survival comparison used Cox proportional hazards regression models. RESULTS: Overall 5- and 10-year survival percentages (± SE) measured from the diagnosis of early-stage breast cancer am...