Breast cancer in pregnancy: an institutional experience

Background: Breast cancer is one of the most common cancers diagnosed during pregnancy. Pregnancy-associated breast cancer (PABC) is defined as breast cancer diagnosed during pregnancy or within 12 months of delivery. Nowadays PABC can be safely diagnosed, staged, and treated during pregnancy with good outcomes for both the mother and the fetus. Recent studies suggest that prognosis of women diagnosed during postpartum seems to be worse. In order to gain a better understanding of the PABC, we reviewed our centre's experience. Patients and methods: We assessed the clinicopathological parameters, evolution, and outcome of patients treated in the Fundacion Instituto Valenciano de Oncologia of Valencia, Spain, from October 1990 to October 2013, and compared the results of patients diagnosed during pregnancy (group 'A') and patients diagnosed within one year of delivery (group 'B'). Of 12,000 cases of breast cancer registered in our database, 35 cases of PABC were identified. We included 11 patients in group 'A' and 24 in group 'B'. Results: In our group the median age was 35 years (range 29-42), of which ten (28%) patients had family history (first grade) of breast cancer, four patients were BRCA 1 mutation carriers. Axillary node compromise was found in 19 patients (53.5%), 24 patients were stage II or III at diagnosis (68.5%), 22 (62.8%) were ER positive, and nine (25.7%) were HER-2 positive. In group A (n = 11), five patients diagnosed before 18th week decided that a therapeutic abortion be performed before treatment, two patients were treated during pregnancy, one with chemotherapy without treatment associated complications during delivery. Four women diagnosed after 28th week decided to delay the treatment until delivery. After a follow up of 172 months, the relapse free survival (RFS) was 69% at five years and 45% at ten years. Overall survival (OS) at five years was 90.8% and 74.2% at ten years for all patients. For group 'A' OS was higher with 90% at five years versus 80% in group 'B'. The differences between the groups were not statistically significant p = 0.368. Conclusion: In our experience, there is a higher OS in patients diagnosed during pregnancy suggesting a better prognosis for this group of women but the difference between the groups is not statistically significant. Our study is limited because of our small sample.