Onkológia 2/2022

Optimal management of patients with breast cancer after progression on CDK4/6 inhibitors.

Despite clear benefit of combined treatment consisting of CDK4/6 inhibors and endocrine treatment, a progression of disease will occur. Endocrine treatment remains the backbone of further treatment. Targeted therapy aiming at activating mutations and proper selection of subsequent endocrine treatment may overcome the acquired resistance. Alpelisib, a PI3Kα inhibitor, prolonged significantly progression- free survival in PIK3CA-mutated patients. PARP inhibitors are approved for patients with BRCA1,2 and/or PALB2 mutation due to their positive effect on survival rates. In patients with no proven activating mutation, everolimus, the efficacy of which was proven in randomized controlled trial, may be used. Maximum utilization of endocrine treatment should be performed before transition to chemotherapy. In case of imminent organ failure, combined chemotherapy should be provided. Tumor-agnostic treatment may be used in case of presence of particular biomarker and in the absence of other tumor- specific treatment.

Keywords: endocrine treatment, endocrine resistance, targeted therapy, PIK3CA mutation, BRCA mutation, PALB2 mutation, mTOR inhibitors, chemotherapy