An early combination of concurrent chemoradiotherapy with immune checkpoint inhibitors for cervical cancer is superior to a late combination: a propensity-score matching analysis.

Purpose: This study compared the timing effects of immune checkpoint inhibitor (ICIs) administration on the efficacy and safety of concurrent chemoradiotherapy for cervical cancer. Methods: This study included patients with advanced cervical cancer who received concurrent chemoradiotherapy with ICIs. The patients were divided into early-application (n=51) and late-application groups (n=56) according to the ICI application timing. The primary objective was assessing progression-free survival (PFS) and its associated factors; secondary objectives included assessing objective remission rates (ORR) and treatment-related adverse events (TRAEs). Results: Before propensity score matching (PSM), the median PFS (mPFS) times were significantly different: 11.5 months (95% CI: 11.0-13.2) and 7.5 months (95% CI: 6.5-9.0) for the early and late groups, respectively (P<0.001). After PSM, the mPFS times remained significantly different: 11.5 months (95% CI: 11.0-13.8) and 6.5 months (95% CI: 6.1-9.0), respectively (P<0.001). The PSM tumor-response ORR in the early combination group (74.3%) was significantly greater than the 31.4% in the late combination group (P<0.001). After PSM, multivariate Cox analysis showed tumor diameter (P=0.004), distant organ metastasis (P=0.047), and timing of combination therapy (P<0.001) were independently associated factors affecting PFS. The most common TRAEs in the two groups of patients were neutropenia, nausea and vomiting, and fatigue, with no significant difference in incidence (P>0.050).All adverse reactions were resolved, and no adverse reaction-related deaths occurred. Conclusion: In patients with cervical cancer treated with concurrent chemoradiotherapy, earlier immunotherapy improves survival and is equivalent in safety to ICIs late application.