CHANGES IN S-PHASE FRACTION AND MICRONUCLEUS FREQUENCY AS PROGNOSTIC FACTORS IN RADIOTHERAPY OF CERVICAL-CARCINOMA

Twenty-five patients with cervical carcinoma were treated with combine d external beam and high dose rate afterloading radiotherapy. Biopsies obtained at different time points in the course of therapy were analy sed with respect to cell proliferation and cytogenetic damage. The fra ction of cells with an S-phase DNA-content as well as the frequency of micronuclei were determined. These two parameters were then related t o treatment outcome, in particular patient survival. Neither S-phase f raction nor the micronucleus frequency before radiotherapy were predic tive of treatment outcome in this small group of patients. However, wh en changes in response to therapy were considered, patients whose S-ph ase fraction decreased and patients whose micronucleus frequency incre ased tended to have a better prognosis. Although statistical significa nce was not achieved with either criterion alone, when applied togethe r the combination predicted patient survival quite reliably; the 5-yea r survival rate of those patients who showed a decrease in S-phase fra ction as well as an increase in micronucleus frequency was about 90% i n contrast to less than 30% for the non-responders (p < 0.03).