Intrinsic radiosensitivity and prediction of patient response to radiotherapy for carcinoma of the cervix.
The intrinsic radiosensitivity of cervical carcinoma has been measured using a soft agar clonogenic assay. All patients received radical radiotherapy alone with a minimum of 2 years post-treatment follow-up. Only women with stage I, II and III disease were included in the analysis. Values for cell surviving fraction at 2 Gy (SF2) were obtained for 88 tumours with an assay success rate of 73%. The 53 patients alive and well at the time of analysis had tumours with a mean SF2 that was significantly lower than the value from the 22 patients with locoregional failure (P < 0.01). Patients with radioresistant tumours (SF2 > 0.40, the median) had a significantly lower 3 year survival level than those with sensitive tumours (SF2 < or = 0.40) (P = 0.002). Also the frequency of local recurrence was higher (P = 0.001) whether these were central (P = 0.009) or peripheral (P = 0.046). Cell surviving fraction at 3.5 Gy was obtained for 46 tumours and the 3 year patient survival rate was significantly higher for those with SF3.5 values less than the median (P = 0.043). There was, however, no difference in the level of local recurrence (P = 0.24). The ability to grow in culture was not associated with significantly poorer patient survival (P = 0.56) or failure to control the primary disease (P = 0.17). While high colony forming efficiencies were associated with an increased rate of local recurrence (P = 0.029) they did not predict for overall patient survival (P = 0.32). These data suggest that, for cervical carcinoma treated with radical radiotherapy, intrinsic radiosensitivity is important in determining treatment outcome.
West
C M
CM
Cancer Research Campaign Department of Experimental Radiation Oncology, Paterson Institute for Cancer Research, Christie Hospital (NHS Trust), Manchester, UK.
Davidson
S E
SE
Roberts
S A
SA
Hunter
R D
RD
D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000401:mortality; D009367:Neoplasm Staging; D011379:Prognosis; D011836:Radiation Tolerance; D011879:Radiotherapy Dosage; D016896:Treatment Outcome; D014410:Tumor Stem Cell Assay; D002583:Uterine Cervical Neoplasms / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*