Monitoring the course of cervical carcinoma with the squamous cell carcinoma serum radioimmunoassay.

Serum samples were collected from 611 gynecologic patients for measurement of squamous cell carcinoma antigen levels using the Abbott Laboratories squamous cell carcinoma antigen radioimmunoassay kit. Sixteen of 83 patients (19.3%) with cervical dysplasia and 72 of 135 (53.3%) with primary or recurrent cervical carcinoma had levels above 2.4 ng/mL. In contrast, only seven of 373 women (1.9%) without genital tract squamous cell intraepithelial neoplasia or carcinoma had squamous cell carcinoma antigen levels above 2.4 ng/mL. Fifty-six patients with cervical cancer were followed for correlation of squamous cell carcinoma antigen levels to disease course, and 20 had persistent or recurrent disease after therapy; rising squamous cell carcinoma antigen levels predicted disease in 15 of these 20 patients with recurrence (13 of 15 with elevated pre-treatment levels and two of five with normal pre-treatment levels). Rising squamous cell carcinoma antigen levels preceded the clinical detection of disease in ten patients by a mean of 4.6 months (range 2-7.5 months); in the remaining five, squamous cell carcinoma antigen levels were elevated only when disease recurrence was documented. Although measurement of squamous cell carcinoma antigen levels is not a sensitive screening method for cervical cancer (sensitivity 53.3%), the test has good specificity (94.3%); the majority of patients with false-positive elevations had other genital tract squamous cell neoplasias. The squamous cell carcinoma antigen assay may be a useful aid for monitoring the disease course of cervical carcinoma.