Pretreatment serum levels of soluble interleukin-2 receptor (sIL-2R), CA 125, and SCC were measured in 183 patients with malignant or benign uterine diseases. Serum sIL-2R levels were higher in the 46 patients with cervical cancer (p < 0.05) or in the 35 patients with endometrial cancer (p < 0.05) than in the 102 patients with benign uterine diseases. Raised serum concentrations of sIL-2R (> or = 50 U/mL), CA 125 (> or = 35 U/mL) and SCC (> or = 2 ng/mL) were found in 50.0%, 15.0% and 67.5% of 40 patients with squamous cell carcinoma of the cervix, respectively. Serum sIL-2R values were > or = 50 U/mL in 83.3% of 6 patients with cervical adenocarcinoma. Elevated serum levels of sIL-2R, CA 125 and SCC were detected in 51.4%, 11.3% and 14.3% of 35 patients with endometrial cancer, respectively. The sensitivity of SCC for squamous cell carcinoma of the cervix was better than that of sIL-2R. On the other hand, we observed that sIL-2R was the most sensitive antigen for endometrial cancer; therefore it could represent a new tumor marker for the management of patients with this malignancy.