Postreatment squamous cell carcinoma antigen as a survival prognostic factor in patients with locally advanced cervical cancer. A Spanish multicenter study. The SEGO Spain-GOG group.

Objective: To evaluate the clinical value of postreatment plasmatic levels of the squamous cell carcinoma antigen (SCC-Ag) as a survival independent prognostic factor in patients with LACC.

Methods: Retrospective, multicenter study including LACC patients (FIGO 2009 stages IB2, IIA2-IVA) managed at the Gynecology Oncological Units corresponding to eight reference hospitals in Spain between 2000 and 2016. Receiver operating characteristic (ROC) curve analysis was used to determine the cut-off values of postreatment SCC-Ag levels in prediction of survival. Survival curves were calculated by using the Kaplan-Meier method and were compared with the log-rank test. Cox models were used to analyze different factors in terms of their prognosis predictive value.

Results: The study included 447 patients with a median follow-up time of 53 months (IQR 26-101) and median pre- and postreatment SCC-Ag levels of 3.4 ng/ml (IQR 1.2-11) and 0.8 ng/ml (IQR 0.5-1.2), respectively. The cut-off level of pretreatment SCC-Ag was 11.75 ng/ml (sensibility 37.5%; specificity 80.5%) and that of postreatment SCC-Ag was 1.24 ng/ml (sensibility 34.6%; specificity 83.1%). In a multivariate Cox regression analysis, factors that were independent predictors of OS were: FIGO stage (HR 2.12; 95%CI 1.18-3.8; p = 0.011), paraaortic lymph node involvement (HR 3.56; 95%CI 2.04-6.2; p < 0.0001), postreatment SCC-Ag level ≥ 1.2 ng/ml (HR 1.95; 95%CI 1.11-3.44; p = 0.02) and incomplete response to treatment (HR 4.5; 95%CI 2.5-8.11; p < 0.0001).

Conclusion: Postreatment plasmatic SCC-Ag level ≥ 1.2 ng/ml was an independent risk factor for the survival of patients with LACC. Further factors influencing survival included: paraaortic lymph node involvement, advanced disease and poor response to concomitant chemoradiotherapy.