Average log change rate of pretreatment squamous cell carcinoma antigen after concurrent chemoradiotherapy in stage IIIC1 cervical squamous cell carcinoma

Abstract

We aimed to determine whether pretreatment squamous cell carcinoma antigen (SCC-Ag) levels and the average logarithmic change in SCC-Ag levels ( $\frac{\Delta log\left(\text{SCC-Ag}\right)}{\Delta \text{time}}$ ) after concurrent chemoradiotherapy (CCRT) could predict treatment outcomes in patients with stage IIIC1 cervical squamous cell carcinoma (SCC). We analyzed 168 patients with stage IIIC1 cervical SCC who underwent primary CCRT and collected data on age, local extension, treatment details, hematological parameters, and tumor markers such as SCC-Ag and carcinoembryonic antigen 21-1 (Cyfra). Predictive performances of pretreatment SCC-Ag levels and $\frac{\Delta log\left(\text{SCC-Ag}\right)}{\Delta \text{time}}$ were assessed using receiver operating characteristic curves. Survival analysis was performed using the Cox regression model and Kaplan-Meier plots. The combination of pretreatment SCC-Ag levels and $\frac{\Delta log\left(\text{SCC-Ag}\right)}{\Delta \text{time}}$ showed higher area under the curve values than pretreatment SCC-Ag levels alone (area under the curve; 95% confidence interval [CI] 0.708 [0.581-0.836] vs. 0.666 [0.528-0.804], respectively). Pretreatment SCC-Ag (≥ 5 ng/ml and Cyfra levels (≥ 3.15 ng/ml) and $\frac{\Delta log\left(\text{SCC-Ag}\right)}{\Delta \text{time}}$ (≥ - 1.575) were significant predictors of disease-specific survival. The 5-year disease-specific survival rates significantly differed among the low-, intermediate-, and high-risk groups. Risk stratification using both pretreatment SCC-Ag levels and $\frac{\Delta log\left(\text{SCC-Ag}\right)}{\Delta \text{time}}$ may predict treatment outcomes of patients with stage IIIC1 SCC.