[Clues to differentiate pregnancy-associated breast cancer from those diagnosed in postpartum period: A monocentric experience of pregnancy-associated cancer network (CALG)]

Abstract

Purpose: To compare epidemiological, histological, therapeutic characteristics and prognosis of patients with breast cancer diagnosed during pregnancy with those diagnosed in postpartum period at a national expert center, « Cancer Associé à La Grossesse » network.

Methods: Retrospective study of 108 patients with a pregnancy-associated breast cancer (PABC) between 2002 and 2016 comparing 51 patients with PABC during pregnancy and 57 patients with PABC of postpartum.

Results: Median gestational age at diagnosis was 16 weeks of gestation (WG). Median size (P=0.92), initial axillary pathology (P=0.29), histological type (P=0.33) and hormone receptor positive (P=0.93), were similar between groups. PABC during pregnancy overexpressed less frequently HER2 (12 % vs 36 %, P=0.003) and were less proliferant (Ki67≥15 %; 64 % vs 75 %, P=0.018) with less radical surgery (45 % vs 70 %, P=0.008). Sentinel lymph node biopsy was performed in 8 patients during pregnancy. Less patients of PABC during pregnancy received trastuzumab 12 % vs 37 %, P=0.003. Median delivery term was 37 WG. Median follow-up 3.2 vs 5.6 years (P=0.002) and recurrence rate for PABC during pregnancy and of postpartum were 3.2 vs 5.6 years (P=0.002) and 12 % vs 32 % (P=0.01), respectively. Our results emphasize histological, surgical and adjuvant treatment differences imposing differentiating PABC during pregnancy from those diagnosed in the postpartum period.

Keywords: Breast cancer; CSAG; Cancer du sein; Chirurgie; Grossesse; Histologie; Histology; PABC; Pregnancy; Recurrence; Récidive; Surgery.