Abstract P1-07-02: 5-year overall survival of early breast cancer during pregnancy: A multicenter French case control study

Abstract

Abstract Background: Breast cancer (BC) during pregnancy (BCP) is a rare situation that requires collaboration between oncologists, surgeons and obstetricians. The main objectives of this study were to compare the overall survival (OS) and disease free survival (DFS) of a multicenter cohort of pregnant patients (pts) with those of matched control pts. Methods: Patients from 27 centers and diagnosed between 2000 and 2006 with histological confirmed M0 invasive BC were included in this retrospective study. For the cohort of BCP, pts whose pregnancy was interrupted were not eligible. Controls were matched to BCP pts on 5 criteria: clinical T (of TNM), hormonal receptor (HR) status, HER2 status, administration of neo-adjuvant chemotherapy and pathological nodal status in the absence of neo-adjuvant chemotherapy. Survival times were estimated from the date of diagnosis using Kaplan-Meier method. OS was calculated until death from every cause, DFS was calculated until relapse or death from every cause; patients alive were censored at the date of last news. Results: 100 BCP pts were identified. Their clinical and pathological characteristics were described on a previous presentation (SABCS 2013 P6-06-07). Matched controls could not be found for 12 BCP pts. 88 BCP pts were matched with 204 controls. The only differences between the 2 populations in terms of characteristics or treatment were more radical mastectomy (p=0.036) and fewer taxane administrations in the BCP group (p=0.06). The median duration of follow-up was 8.2 years for cases and 7.7 years for controls. There were no differences between BCP pts and controls in 5-year OS: 83.4%, IC 95% (73.5-89.8) vs 83.8%, IC 95% (77.9-88.3) nor 7-year OS: 76.5% (65.5-84.4) vs 78.1% (71.5-83.3) (p=0.52). The 5-year DFS was 58.6% IC 95% (47.3-68.3) vs 67.2% IC 95% (60.2-73.2) (p= 0.16). However, 5-year DFS was lower in HR+ BCP pts subgroup than in HR+ control group (56.7% IC 95% (40.7-69.8) vs 70.9% IC 95% (61.4-78.5) (p=0.023). Conclusion: This multicenter French large study confirmed that there are no differences on OS and DFS between pregnant and no pregnant pts, though this might not be true for HR subgroup. Citation Format: Vanlemmens L, Ploquin A, Delaloge S, Rouzier R, Lesur A, Frenel J-S, Loustalot C, Bachelot T, Provansal M, Ferrero J-M, Coussy F, Debled M, Kerbrat P, Vinceneux A, Djelila A, Baron M, Jebert S, Decoupigny E, Tresch E, Bonneterre J. 5-year overall survival of early breast cancer during pregnancy: A multicenter French case control study. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-07-02.