Squamous cell carcinoma antigen for monitoring cervical cancer.

The tumour-associated antigen was determined in the plasma of patients with squamous cell carcinoma (SCC) of the uterine cervix by radioimmunoassay. Setting a limit of 2 ng/ml, levels were abnormal in 13.4% of healthy controls, in 14% of patients with carcinoma in situ and in 62% of patients with invasive cervical SCC. The incidence of elevated SCC antigen levels and the absolute antigen plasma concentration were dependent upon the tumour load, increasing significantly with advanced stage disease. Abnormal SCC antigen values in operable cervical cancer declined to normal within one week after radical hysterectomy with pelvic lymphadenectomy. In cases of radiotherapy antigen values took 4-6 weeks after the start of treatment to return to normal. The success of both treatment modalities was announced by an early rise in the SCC antigen in the initial phase of therapy, followed by normalisation. After successful primary treatment and a complete remission during further follow-up SCC antigen in plasma was only increased in 3.8% of the cases. Retrospective evaluations in ten patients with progressive disease showed the reappearance of abnormal SCC titers and further increase preceeding the clinically detectable relapse or progression, with a median interval of 8 weeks. The present study indicates that SCC antigen determination is not useful for the early diagnosis of cervical cancer, but it is a potential means for monitoring the efficacy of individual anticancer therapy of SCC of the uterine cervix and for detecting recurrent disease.