Prognosis of triple-negative breast cancer associated with pregnancy: A propensity score-matched analysis from the French CALG (Cancer Associé à la Grossesse) network

Abstract

IntroductionTriple-negative (TN) breast cancer represents one third of pregnancy-associated breast cancers (PABC). The aims of the current study were to describe oncological and obstetrical outcomes of patients with TN-PABC and to compare their prognosis with TN-non-PABC patients using a propensity score. Materials and methodsBetween January 2005 and December 2020, data of patients with histologically proven TN-PABC were collected and compared with data of TN-non-PABC patients under the age of 46 years diagnosed during the same period using a propensity score (PS). ResultsAfter PS matching (tumor size and lymph node involvement),there were 59 patients in each group. The median follow-up was 14 months (IQR 4.8–40.1) for the TN-PABC group and 60 months (IQR 30.7–101.4) for the TN-non-PABC group. Eight recurrences occurred in the TN-PABC group and 10 in the TN-non-PABC group (adjusted OR (AOR) = 0.60 (0.21–1.60), HR (Cox adjusted model- AHR) = 1.25 (0.53–2.94)). Two patients died in the TN-PABC group, and six in the TN-non-PABC group with an AOR = 0.23 (0.03–1.01) and an AHR = 0.58 (0.12–2.69). All the patients diagnosed during the second (n = 17) and third trimesters (n = 28) continued their pregnancies, with a median term at delivery of 38 WG (IQR 36–39). All patients gave birth to healthy newborns. ConclusionAlthough the TN subtype is associated with poor prognosis in pregnant patients due to advanced stage at diagnosis and high lymph node involvement, our PS-matched case-control study showed that pregnancy per se does not worsen the prognosis in terms of recurrence-free and overall survival.