AUTHOR=Qi Wei-Xiang , Cao Lu , Xu Cheng , Cai Gang , Chen Jiayi 

TITLE=The optimal regional irradiation volume for breast cancer patients: A comprehensive systematic review and network meta-analysis of published studies

JOURNAL=Frontiers in Oncology

VOLUME=Volume 13 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2023.1081201

DOI=10.3389/fonc.2023.1081201

ISSN=2234-943X

ABSTRACT=Background: Currently, the optimal adjuvant regional irradiation volume for early-stage breast cancer (BC) remains controversial. We aim to define the optimal RNI treatment volume for early-stage BC by using a comprehensive network meta-analysis (NMA) of published studies. 
Materials and methods: PubMed, Embase, Medline, and Cochrane Central Register of Controlled Trials were searched from database inception to May 30, 2022. Trials assessing different regional node irradiation (RNI) volume for early-stage BC were eligible for inclusion. The primary outcome was overall survival (OS), and secondary outcome was disease free survival (DFS) and distant metastasis free survival (DMFS). 
RESULTS 
A total of 29,640 early-stage BC from twenty trials were included. The pooled hazard ratio demonstrated that radiotherapy with internal mammary node irradiation (IMNI) in early-stage BC significantly improved OS giving HR 0.87 (95%CI: 0.83-0.91, p<0.001), DFS with HR of 0.78 (95%CI: 0.68-0.90, p<0.01) and DMFS with HR of 0.87 (95%CI: 0.79-0.97, p<0.01) when compared to controls. Sub-group analysis indicated that RNI with IMNI significantly improved OS (HR 0.87, 95%CI: 0.81-0.93, p<0.01), DFS (HR 0.65, 95%CI: 0.56-0.77, p<0.01) and DMFS (HR 0.90, 95%CI: 0.82-0.98, p=0.02) when compared to RNI without IMNI. NMA showed that CW/WB  +RNI with IMNI significantly improved DFS (HR 0.93, 95%CI: 0.86-1.00) and DMFS (HR 0.90, 95%CI: 0.81-0.99), but not for OS (HR0.93, 95%CI: 0.84-1.03) when compared to CW/WB alone. Based on the analysis of the treatment ranking, CW/WB+RNI with IMNI appeared as the best treatment approach for early-stage BC.
CONCLUSIONS 
Our pooled results confirm that RNI with IMNI yields a significant survival advantage for early-stage BC. NMA indicates that CW/WB+RNI with IMNI is the optimal radiation volume for early-stage BC.