Background
Triple-negative breast cancer (TNBC) has a very high rate of recurrence and till now there is no standard of care. Because of the sensitivity of TNBC to platinum compounds and the synergistic effect between bevacizumab and paclitaxel according to many studies, our aim was to combine all these agents to evaluate the efficacy of bevacizumab in combination with carboplatin and paclitaxel as first-line treatment in metastatic TNBC (mTNBC) and to predict whom can benefit from this combination.
Methods
This prospective phase two study included 54 female patients diagnosed with mTNBC at the Clinical Oncology Department, Assuit University Hospital, Egypt from 2017- 2019, 40 of them diagnosed after adjuvant treatment and 14 as denovo. They received bevacizumab 15 mg/ kg + carboplatin AUC 6 + paclitaxel 175m.g/m2 every 21 day for 8 cycles then followed up till data cut off in February 2021. Primary end point was progression-free survival (PFS) at 2 years. Secondary end points were overall survival (OS) at 2 years. Kaplan Meier curve and regression tests were used.
Results
Evaluation was done Feb 2021; 32 patients were alive and only 26 out of them remained in the study. 15 (57.7%) still in CR, 2 (7.7%) were PD and 9 (34.6 %) SD and ORR was 57.7 %, DCR was 92.3 %. Median PFS at 2 years was 27 months with (95 % CI 17.019 - 36.981). By Cox regression both viseral only disease and performance status (PS) 0 had longer PFS (HR 0.23, P value = 0.05) and (HR = 0.16, P value = 0.02) respectively with C index 0.77. The 2 year median OS was 55 months (95 % CI 38.973 - 71.027). Both type of presentation either denovo or after adjuvant treatment and also PS conistentaly affect OS with C index 0.73; (HR = 7.91, P value = 0.02) for denovo patients and (HR=0.12 - P value = 0.01) in patients with PS 0. Three factors affecting final response to gain either SD or CR; patients with visceral only disease OR was 13.20 (P value 0.001), patients with PS 0 had the highest OR 19.5 (P value 0.001) with prediction value 70.4 % and having ≤ 3 sites of metastasis (OR 3.92 P value = 0.02) and 64.8% as percentage of prediction.
Conclusions
TNBC became a challenging area of research to improve the patients’ survival and quality of life. We concluded that tumor burden and PS significantly can be useful in predicting efficacy and tolerability of bevacizumab in metastatic stage in terms of response, PFS and OS.
Clinical trial identification
NCT03577743, ID: BMTN.
Legal entity responsible for the study
Assuit University Hospitals Faculty of Medicine.
Funding
Has not received any funding.
