Efficacy of the second line chemotherapy in patients with metastatic triple negative breast cancer. Results of randomized study

Lyalkin S.A., Verevkina N.O., Syvak L.A.

Summary. The results of therapy of patients with metastatic triple negative breast cancer (mTNBC) remain unsatisfactory. Chemotherapy (CT) remains standard of care for metastatic triple negative breast cancer, although no agent, combination or sequence (chemotherapy lines) have been specifically approved for this breast cancer subtype. Aim — to evalu­ate the efficacy of the second line CT in patients with mTNBC. Object and methods. The randomized study was performed, 87 patients with mTNBC were included. Patients received monochemotherapy with vinorelbine (n=29), gemcitabine (n=29) and capecitabine (n=29). All of them received the first line treatment with the use of anthracyclines, taxanes and platinum salts. Results. Disease control was statistically significantly more often achieved in patients who received vinorelbine or gemcitabine compared with patients who received capecitabine (p=0.02). There were no significant differences between the first two groups. Patients has different grade 3–4 toxicity profiles: neurotoxicity in vinorelbine group (р<0.05), diarrhea in capecitabine group (р<0.05), neutropenia and thrombocytopenia in gemcitabine group (р<0.05.). There was no statistically significant difference in disease free survival (Log-rank test; p=0.43) and overall survival (Log-rank test; p=0.76) patients in 3 groups. Conclusions. The «vinorelbine-mono» and «gemcitabine-mono» regimens are more effective as second-line palliative CT than the «capecitabine-mono» regimens. The incidence of disease control (partial response + stabilization) was 89.7% in patients received vinorelbine, 75.9% in gemcitabine group and 58.6% in capecitabine group (р=0.02). There was no difference in the efficacy between vinorelbine and gemcitabine (р>0.05).