Influence of age, prior abdominal surgery, fraction size, and dose on complications after radiation therapy for squamous cell cancer of the uterine cervix. A patterns of care study.

The 1973 and 1978 national surveys conducted by the Patterns of Care Study (PCS) for squamous cell cancer of the uterine cervix were combined to analyze factors associated with complications after radiation therapy (RT). Overall, 1558 patients were reviewed, with a median follow-up of 43 months. Major complications (defined as necessitating hospitalization for management) were seen in 152 of 1558 (9.8%) patients, with a 5-year actuarial rate of 14%. A number of pretreatment and treatment factors were analyzed with respect to complications. In univariate analysis, significant pretreatment and treatment factors associated with an increase in complications included young age, prior laparotomy for staging, history of prior abdominal surgery, increasing stage, use of external RT, high fraction size, cesium source, and high paracentral (PCS point A) and lateral (PCS point P) doses. Multivariate analysis showed a history of prior abdominal surgery, paracentral dose greater than 7500 cGy, use of cesium, daily fraction size greater than 200 cGy, and age younger than 40 years to be associated independently with complications. A detailed analysis of the type of and time to complications is presented. The knowledge and skillful management of these pretreatment and treatment factors may improve the therapeutic ratio for RT, which is the most active curative modality against cervical cancer.