Predictors of response to neoadjuvant chemo-immunotherapy in metaplastic triple-negative breast cancer

Le résumé fourni par la source

Metaplastic breast cancer (MpBC) treated with standard chemotherapy has low rates of complete pathological response (pCR)(2-23%). In this study, we evaluate the response to neoadjuvant chemo-immunotherapy (NACI) in early-stage MpBC. Thirty-two stage I-III MpBC patients treated with NACI (KEYNOTE-522 regimen) were prospectively enrolled in an institutional rare tumor program. All MpBC were triple negative; most were of chondromyxoid/matrix-producing (12/32, 38%). The majority had stage II (78%) tumors, 12/32 (37.5%) patients completed NACI, 11/32 (34%) progressed during NACI, and in the remaining 9, NACI was discontinued due to side effects. The pCR rate in the entire cohort was 22% (7/32) and it was statistically higher (5/8, 62%) among patients with high ( ≥ 60%) stromal tumor-infiltrating lymphocytes (sTILs) as compared to patients with < 60% sTILs (1/11, 9%). Most patients received adjuvant systemic therapy (capecitabine 16/32, pembrolizumab 20/32). At a median follow-up of 13 months, there were a total of 2 local recurrences, 10 distant recurrences, and 7 deaths. We demonstrated a modest pCR rate in MpBC with the addition of pembrolizumab (22%). Nonetheless, amongst patients with high sTILs, high pCR rates-comparable to those in the KEYNOTE-522 trial-were observed. These findings suggest that sTILs can be used to triage MpBC patients for NACI.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.