Brachytherapy-based local radiotherapy improves survival in newly diagnosed metastatic cervical cancer.

To explore if adding local radiotherapy to systemic treatment could enhance the survival of newly-diagnosed stage IVB cervical cancer (CC) patients and compare the impact of different radiotherapy strategies on survival. We included patients diagnosed from 2004 to 2022. Local radiotherapy strategies included external beam radiotherapy (EBRT) and/or brachytherapy (BT). Multivariable Cox regression models were used to assess the link between treatment modality and survival. A total of 4257 patients were involved, all receiving chemotherapy. There were 1280 (30.1%), 2,089 (49.1%), 759 (17.8%), and 129 (3.0%) patients who received chemotherapy alone, chemotherapy plus EBRT, chemotherapy plus EBRT and BT, and chemotherapy plus BT. Using the chemotherapy plus EBRT and BT group as a reference, those on chemotherapy alone had a higher risk of death (cancer-specific survival [CSS]: hazard ratio [HR] 2.037, P < 0.001; overall survival [OS]: HR of 1.992, P < 0.001). Similarly, chemotherapy plus EBRT patients also had an increased risk (CSS: HR 1.576, P < 0.001; OS: HR 1.582, P < 0.001). However, there were no significant differences in CSS (HR 1.082, P = 0.504) and OS (HR 1.083, P = 0.476) between the chemotherapy plus BT group and the reference group. Sensitivity analyses indicated that chemotherapy plus BT and chemotherapy plus EBRT and BT improved survival across subgroups. Our study reveals that adding any form of radiotherapy to chemotherapy for stage IVB CC patients improves survival. BT, alone or combined with EBRT, offers the best outcomes, while EBRT alone has a limited advantage over chemotherapy alone. BT-based local treatment may serve as an effective local treatment option for stage IVB CC.