Prognostic significance of S-phase fraction detected by antithymidine antibodies in epidermoid cervix carcinomas.

Purpose: To assess the predictive value of pretreatment proliferative activity of epidermoid cervix carcinoma cells with respect to short- and long-term results of radiotherapy.

Methods And Materials: The proliferative activity of 25 epidermoid cervix carcinomas was evaluated as the immunofluorescent labeling index (LI) by rabbit antithymidine antibodies reacting specifically with single-stranded DNA of replication forks in S-phase cells. The short-term clinical outcome was estimated at 3-6 months after treatment by visual and palpatory examination. Three-year follow-up data were obtained through hospital charts and correspondence with referring physicians for only 19 patients.

Results: There was no statistically significant association between LI and such conventional prognostic factors as clinical stage. The LI value of cervix carcinomas was significantly associated with complete regression at 3-6 months after radiotherapy and 3-year disease-free survival. Complete regression at 3-6 months was observed in 87.5% patients with fast proliferating tumors (LI > 7.0%), and only in 41.2% patients with slowly proliferating tumors (p = 0.03). Probability of 3-year disease-free survival was 85.7% in patients with fast proliferating tumors and 50.0% in those with slowly proliferating tumors (p = 0.05).

Conclusions: The immunofluorescent LI of epidermoid cervix carcinoma is able to provide prognostic information on short-term tumor response to radiotherapy and disease-free survival.