Title:Efficacy and Safety of Atezolizumab Monotherapy or Combined Therapy with
Chemotherapy in Patients with Metastatic Triple-negative Breast Cancer: A
Systematic Review and Meta-analysis of Randomized Controlled Trials
Volume: 29
Issue: 31
Author(s): Mina Alimohammadi, Fatemeh Faramarzi, Alireza Mafi, Tahoora Mousavi, Ali Rahimi, Hamed Mirzaei*Zatollah Asemi*
Affiliation:
- Research Center for Biochemistry and Nutrition in Metabolic Diseases, Kashan University of
Medical Sciences, Kashan, Iran
- Research Center for Biochemistry and Nutrition in Metabolic Diseases, Kashan University of
Medical Sciences, Kashan, Iran
Keywords:
Atezolizumab, mTNBC, efficacy, safety, meta-analysis, chemotherapy, breast cancer.
Abstract:
Introduction: Several successful attempts have been recorded with PD-L1 blockade via atezolizumab
monotherapy or combination therapy with chemotherapy in patients with metastatic triple-negative
breast cancer (mTNBC). Due to the lack of a large-scale study, we present a meta-analysis aimed at evaluating
the safety and efficacy of this promising strategy in patients with mTNBC.
Methods: A comprehensive literature search was conducted using electronic databases to identify eligible
RCTs. Twelve studies, including 2479 mTBNC patients treated with atezolizumab monotherapy or in combination
with chemotherapy, were included up to January 2022. The PRISMA checklist protocol and the I2 statistic
were applied for quality assessment and heterogeneity tests of the selected trials, respectively. Fixed and
random-effects models were estimated based on the heterogeneity tests, and statistical analysis was performed
using CMA.
Results: Our pooled findings demonstrated that the median overall survival (OS) and progression-free survival
(PFS) were 16.526 and 5.814 months in mTNBC patients, respectively. Furthermore, when comparing efficacy
indicators between PD-L1-positive and PD-L1-negative groups, mTNBC patients with PD-L1 had better
OS, PFS, and ORR than PD-L1-negative patients. Also, the immune-related adverse event incident for alopecia
was higher (51.9%) than other complications across atezolizumab therapy.
Conclusion: Moreover, the pooled analysis indicated that the overall rate of lung metastasis following atezolizumab
therapy was 42.8%, which was higher than the rates of metastasis in bone (26.9%), brain (5.4%),
and lymph node (6.5%). Atezolizumab showed a manageable safety profile and had promising and durable
anti-tumor efficacy in TMBC patients. Higher PD-L1 expression may be closely correlated with better clinical
efficacy.
