THE INDEPENDENCE OF INTRINSIC RADIOSENSITIVITY AS A PROGNOSTIC FACTORFOR PATIENT RESPONSE TO RADIOTHERAPY OF CARCINOMA OF THE CERVIX

A study was made of the prognostic value of pretreatment measurements of tumour radiosensitivity (surviving fraction at 2 Gy, SF2) in 128 pa tients with stage I-III carcinomas of the uterine cervix undergoing ra diotherapy. The median follow-up time was 47 months. In a univariate a nalysis stratifying patients according to the median value, radiosensi tivity was a significant prognostic factor for overall survival, local control and metastasis-free survival. The 5-year survival rate for tu mours with SF2 values below the median was 81% and was significantly g reater than the rate of 51% for those with SF2 values above the median . In bivariate analyses, SF2 was shown to be independent of disease st age, tumour grade, patient age, colony-forming efficiency and tumour d iameter. In a multivariate analysis, radiosensitivity was the most imp ortant variable and, after allowing for this, only stage was a signifi cant independent predictor of treatment outcome. These data indicate t hat, in carcinoma of the cervix treated with radiotherapy, pretreatmen t tumour intrinsic radiosensitivity is an important prognostic paramet er and contributes to prognosis independently of other established and putative parameters.