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 less than or equal to 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 I 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.