Squamous cell carcinoma antigen in serum for monitoring of head and neck and uterine cervical squamous cell carcinomas after radiotherapy.

Squamous cell carcinoma antigen (SCC-A) in serum was serially measured during follow-up of 96 squamous cell carcinoma patients (75 head and neck cancers and 21 uterine cervical cancers), treated with radiotherapy. In 27 of the patients with head and neck cancer and in 12 of those with cervical cancer SCC-A had also been measured before radiotherapy. In this head and neck carcinoma group, the median level of SCC-A was 1.3 (95% CI: 1.2-1.9) ng/ml before radiotherapy and 1.4 (CI: 1.1-1.5) ng/ml after radiotherapy. In the cervical carcinoma group, the median SCC-A decreased significantly (p < 0.001) from a pretreatment value of 7.5 (CI: 3.8-26.3) ng/ml to a posttreatment value of 0.9 (CI: < 0.5-1.8) ng/ml. In the total group of 75 head and neck cancers 21 relapses occurred and in 4 of these the relapse was detected at a clinically silent stage by an elevation of serum SCC-A. The same was true for 4 of the 9 relapses that occurred in the total group of uterine cervical cancer. The study suggests that serum SCC-A may be useful for posttreatment monitoring of patients with uterine cervix cancer while its value in head and neck cancer probably is more marginal.