Abstract P6-06-07: 5-year disease free-survival results of aggressively-treated breast cancer during pregnancy: Results from a French multicenter study
Authors: Vanlemmens L , Delaloge S , Ploquin A , Bachelot T , Frenel J-S , Loustalot C , Kerbrat P , Mignot L , Debled M , Allouache D , Vinceneux-Confavreux A , Provansal M , Dalenc F , Mouret-Reynier M-A , Lerebours F , Jacot W , Tartas S , Morvan F , Jebert S , Decoupigny E , Rouzier R 
Published: August 2014

Background: Breast cancer (BC) during pregnancy (BCP) is a rare situation that requires multi-disciplinary management. The objectives of this study were to assess the tumor characteristics, clinical course and outcome of such patients (pts).

Methods: French hospitals were invited to collect retrospective clinical, treatment and follow-up data of BCP managed between 2000 and 2006. Pts with histologically confirmed M0, invasive BC and pregnant at diagnosis were included. Pts whose pregnancy was interrupted were not eligible. Survival times were calculated from the date of diagnosis.

Results: 100 BCP pts were identified. Median age was 32 years (24-42). Median gestational age at diagnosis was 25 weeks (3-38). 84% and 13% had palpable breast axillary mass respectively. Clinical stages were 1T0, 21T1, 39T2, 28T3, 6 T4A-C, 2 T4D, 3 TX, 56 N0, 39 N1, 5 NX. Histological analysis identified 85 ductal carcinomas, 4 lobular, 11 others. The histopathological grades was G1 in 4,3%, G2 in 29%, and G3 in 66,7%. Tumor subtype was luminal A in 3%, luminal B in 37% (24HER2-, 13HER2+), luminal undetermined in 6%, triple-negative in 45,9%, Her2 + in 21,3%, and not classified in 2% (HR -, HER 2 unknown). Median time interval between first observation and biopsy was 31 days (0-337), respectively 40 days (0-337) and 15 days (0-172) when the first observation was made by patients or physicians. Median time interval between pathologic diagnosis and treatment was 18 days (0-295). Treatment was initiated after pregnancy for 42 pts, with median time of 18 days after delivery. 97 pts received chemotherapy with a median number of 6 cycles (4-11), 92 with anthracyclin, 44 with taxanes. 53 chemotherapy were administered in neo adjuvant setting among which 25 during pregnancy), and 44 in adjuvant setting (23 during pregnancy). 98 pts underwent surgery (34 during pregnancy), with 57 conservations and 41 mastectomies, 93 pts received radiotherapy and 43 hormone therapy after pregnancy. 10 pts received Trastuzumab. The mean gestational age at delivery was 35 weeks (22-45). All children were alive, with a median weight of 2735 g at birth (550-3740). The 5-year Overall Survival rate is 83% (95%CI 74-89), while Disease Free Survival is 53% (95%CI 43-63). First recurrence site was metastasis in 28, locoregional in 13, controlateral in 9 and other cancers in 2.

Conclusion: Biopsy and treatment intervals remain long among this population. In this large series BCP, there is an excess of triple-negative breast cancer. The 5-year OS rate is higher than previously reported but with DFS is lower. BCP remains an aggressive entity despite adapted treatment. Multivariate analysis will be presented. A comparison of this BCP population to matched controls is ongoing.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-06-07.