To investigate the prognostic value of pretreatment squamous cell carcinoma antigen (SCC Ag) levels for treatment failure prediction in patients with cervical cancer.

A quantity of 985 patients satisfying the eligibility criteria were included, with a median follow-up duration of 63.7 months. The optimal cutoff value for pretreatment SCC Ag levels was verified by the receiver operating characteristic (ROC) curve. Five-year disease-free survival (DFS), overall survival (OS), and local control (LC) rates were evaluated utilizing the Kaplan-Meier method. Log-rank test and Cox proportional hazards model was implemented to recognize independent prognostic predictors.

The optimal pretreatment SCC Ag cutoff value was 8.85 ng/mL. Patients with pretreatment SCC Ag levels ≥ 8.85 ng/mL presented significantly inferior 5-year DFS (63.8% vs. 81.8%), OS (71.7% vs. 88.7%), and LC (80.5% vs. 91.0%) compared to those with levels < 8.85 ng/mL (all p < 0.001). The results of the multivariate analysis indicated that the pretreatment SCC Ag level was an independent predictor of treatment failure (HR,1.772; 95% CI, 1.366 to 2.299; p < 0.001).

Pretreatment SCC Ag is an effective prognostic factor in patients with cervical cancer undergoing definitive radiotherapy, with a ROC-identified cutoff value of 8.85 ng/mL and elevated SCC Ag indicates unfavorable outcomes.