Hydroxyurea: a radiation potentiator in carcinoma of the uterine cervix. A randomized double-blind study

From June, 1972, to December, 1976, 40 patients with FIGO (International Federation of Gynaecology and Obstetrics) Stage IIB carcinoma of the uterine cervix were entered into a prospective, double-blind, randomized study to evaluate the possible radiation-potentiating properties (i.e., improved survival) of the S-phase cell cycle-specific inhibitor of DNA synthesis, hydroxyurea. All patients were documented to be without aortic lymph node metastasis by pretherapy staging para-aortic lymphadenectomy. All 40 patients were followed up for longer than 5 years (5.2 to 9.2 years) or until death. The double-blind code was not broken until all patients had been followed up for a minimum of 2 to 5 years. Leukopenia (white blood cell count less than 2,500 mm3) was significantly increased in the patients given hydroxyurea as compared to those given placebo (P less than 0.0001). There was no statistically significant difference relative to anemia, thrombocytopenia, radiation-induced skin reaction, and radiation-induced intestinal reaction between the patients given placebo or those given hydroxyurea. Life-table survival for the patients given hydroxyurea was 94% as compared to 53% for the patients given placebo (P = 0.006). Only one (5%) patient given hydroxyurea died of cervical cancer. Of the other patients who died in the group given hydroxyurea, all were confirmed by postmortem examination to have been without recurrent cervical cancer. In contrast, 45% (nine) of the patients given placebo died of cervical cancer.