Effects of pregnancy after treatment for breast carcinoma on survival and risk of recurrence

BACKGROUND: The goal of the current study was to assess the effect of pregnancy on the subsequent risk of recurrence after treatment for breast carcinoma, adjusting for established prognostic factors. METHODS: Between 1974 and 1998, 383 patients age < or =35 years were treated for breast carcinoma with adjuvant chemotherapy at The University of Texas M. D. Anderson Cancer Center (Houston, TX). The median follow-up period was 13 years. Of these, 13 patients were excluded from analysis, as no history was available regarding pregnancy; 240 (65%) were >30 years old; 47 (13%) had at least 1 pregnancy after therapy; 32 had full-term pregnancies; 10 had spontaneous or elective abortions; 4 had miscarriages; and 1 had a premature delivery. Estrogen receptor (ER) status, lymph node involvement, and disease stage were evaluated as potential risk factors for recurrence. Information on ER status was unavailable for 123 (33%) patients. RESULTS: Patients who experienced a pregnancy tended to have earlier-stage disease (Stage I/II: 80% vs. 73%), fewer positive lymph nodes (<4: 87% vs. 52%), more ER negativity (68% vs. 58%), and younger age (<30 years: 57% vs. 32%) than patients who did not. The incidence of disease recurrence was 23% for women who experienced a pregnancy and 54% for women who did not. The hazard ratio (using the multivariate Cox proportional hazards model) for disease recurrence in patients with posttreatment pregnancy was 0.71 (P=0.4). CONCLUSIONS: In the current study population, pregnancy was not associated with an increased risk of disease recurrence or poorer survival in patients previously treated for breast carcinoma.