The role of pretreatment squamous cell carcinoma antigen level in locally advanced squamous cell carcinoma of the uterine cervix treated by radiotherapy.

The purpose of this study was to determine the pretreatment serum squamous cell carcinoma antigen (SCC-ag) level as a generally applicable measurement in predicting and estimating the treatment outcome of patients with locally advanced SCC of the cervix. Three hundred fifty-two patients with stage IIB-IVA SCC of the cervix were managed with both external irradiation and high-dose rate intracavitary brachytherapy. A significantly higher median SCC-ag was seen in association with increasing stage, tumor size, and lymph node involvement. The difference in disease-free survival (DFS) between stages IIB and III patients was not statistically significant with SCC-ag level <2 ng/mL. In multivariate analysis, median SCC-ag level (> or =6.0 ng/mL) and lymph node metastases had significant independent effects on absolute survival and DFS. A direct linear relationship (y=-2.932x+ 84.896) existed between the median SCC-ag of groups distributed by pretreatment prognostic factors and the 5-year DFS rate. The 5-year DFS rate as a function of SCC-ag level defined by cervix size, lymph node status, and hydronephrosis was obtained from a formula combining risk scores and the baseline survival function. From the obtained formulas, we can objectively estimate the treatment outcome in patients with locally advanced squamous cell cervical cancer.