Purpose: To determine the time course and incidence of late complications from radiation therapy in patients treated with radiation for FIGO Stage IB carcinoma of the uterine cenix, and to evaluate patient and tumor factors associated with an increased probability of treatment complications. Methods and Materials: The medical records of 1784 patients with FIGO Stage IB cervical carcinoma who were treated with initial radiation therapy between 1960 and 1989 were retrospectively reviewed. Follow-up was obtained from clinic visits and correspondence with patients and their physicians. Treatment complications were graded retrospectively. Complication rates were calculated actuarially; patients who died of disease or intercurrent illness without experiencing a major complication were censored at the time of death. There were 1241, 924, 548, and 274 patients followed for more than 5, 10, 15, and 20 yeats, respectively. Results: Of patients treated for Stage IB cervical carcinoma, 7.7% and 9.3% had experienced major (greater than or equal to Grade 3) complications at 3 and 5 years, respectively. After 5 years, there was a small but continuous risk of approximately 0.34% per year, resulting in an overall actuarial risk of:having had major complications of 14.4% at 20 years. The risk of developing major urinary tract complications was approximately 0.7% per year for the first 3 years of follow-up, decreasing to about 0.25% per year for at least 25 years. In contrast, the risk of developing rectal complications was about 1% per year during the first 2 years, with a subsequent sharp decline to about 0.06% per year between Yeats 2 and 25. The risk of fistula formation was approximately doubled in the 234 patients who underwent adjuvant extrafascial hysterectomy (53 vs. 2.6% at 20 years; p = 0.04) and in the 111 patients who had pretreatment laparotomy (5.2 vs. 2.9%;p = 0.007). The risk of developing small bowel obstruction was increased in patients who underwent pretreatment laparotomy (14.5 vs. 3.7% at 10 years; p < 0.0001) and in patients who weighed <120 pounds (82 vs. 3.6%;p = 0.004), but was not increased in patients who underwent adjuvant hysterectomy. A significantly greater risk of gastrointestinal complications was observed in black and non-Hispanic white patients than in Hispanic women (p = 0.01), even though there was no difference in the rate of developing urinary tract complications (p = 1.0). There was no correlation between the actuarial risk of developing major complications and the patients' age at the time of treatment, but the cumulative risk was greater for patients who were treated at a young age because these patients were more likely to survive to be exposed to a very long period of risk. Conclusions: Using techniques described by Fletcher and Delclos, the risk of major complications from aggressive irradiation for Stage IB carcinoma of the cervix is low:and does not warrant compromises in the intensity of treatment that might decrease the high cure rates achieved in such patients. The long time course of some late complications also suggests that continued surveillance of survivors, by physicians experienced in the diagnosis and management of the sequelae of the curative radiation treatment of cervical cancer, is important.
