Long-term Outcomes of Pregnancy-Associated Breast Cancer: A Single Institution Experience

Background: The incidence of pregnancy-associated breast cancer (PABC) is increasing, especially in the developed countries. Herein, we report the long-term outcomes of PABC from a single institution in an Arab country. Methods: Consecutive patients diagnosed to have PABC between 2005 and 2012 at a tertiary referral hospital from a Gulf cooperation council country were the subjects of the study. Long-term outcomes are reported, with a minimum follow-up of 8 years. Results: A total of 16 patients were evaluable for long-term survival analysis. The median age at the time of diagnosis was 31.5 (26-40) years. Nine (56%) patients were multiparous (> 5 previous pregnancies). The mean gestational age at diagnosis was 19.7±7.4 weeks. Immunohistochemistry revealed the following phenotypes: Luminal A 3 (18.8%); HER-2 enriched 8 (50%); triple-negative 5 (31.2%). Three patients underwent modified radical mastectomy as the initial treatment, of which 2 received adjuvant chemotherapy during pregnancy. For patients who received neoadjuvant or palliative chemotherapy, the response rate was 75% (pCR 2; CR 1; PR 6). After a median follow-up of 60 months, median progression-free survival was 36 months (95%CI 24.2 to 47.8), while the overall survival was 59 months (95%CI 31.6 – 86.4). Age, marker status, Ki-67 score, clinical stage and differentiation grade did not affect the PFS or OS on univariate analysis. Conclusions: Fifty percent of the patient with PABC expressed HER-2/neu protein, and 1/3rd had triple-negative disease. The rate of response to chemotherapy, and long-term survival may help to set a benchmark for studies from the region. Larger cohort studies may help to draw firm conclusions.