OBJECTIVES: Metastatic triple-negative breast cancer (TNBC) corresponds to between 2,717 and 3,093 diagnoses in France every year according to the French National Authority for Health (HAS). The approval of Keytruda in combination with chemotherapy in patients with mTNBC raised the question of the applicability of its combination with carboplatin+gemcitabine (CG), used in the KEYNOTE-355 trial, to French clinical practice. The aim of this study was to quantify the use of the CG regimen in mTNBC patients before the approval of Keytruda in association with this protocol.

METHODS: All newly hospitalized (without hospitalization in the 5 preceding years) patients with metastatic (C77, C78, C79) breast cancer (C50) between 01/01/2017 and 31/12/2020 were followed until the end of the study period (31/12/2020) or in-hospital death. To exclude non-TNBC patients, patients without any chemotherapy session (Z51.1) and/or with administration of an anti-HER2+ treatment or a treatment/procedure suggesting a RH+ status were excluded. In the remaining population, specific mTNBC management with CG in intra-DRG was sought using an algorithm (ATLAS) that compares the frequency of chemotherapy sessions with a theoretical regimens of 3 cycles (deemed sufficient to discriminate this protocol) of 21 days with a D0-D7-D21 injections regimen.

RESULTS: Overall, between 2017 and 2020, ATLAS identified a CG regimen for more than 21 days in 1,358 patients and for more than 42 days in 1,032. Among all CG regimen identified, 14-16% were identified in 2017, 23% in 2018, 32-34% in 2019 and 29-30 % in 2020.

CONCLUSIONS: This algorithm approximated the number of mTNBC patients treated with the CG protocol in France. The number of patients benefiting from this protocol and the increase in its use over time are consistent with the data reported by HAS in the efficiency opinion of Keytruda and the recent integration of this therapeutic option into management in France, respectively.