Subsequent malignancies associated with carcinoma of the uterine cervix: including an analysis of the effect of patient and treatment parameters on incidence and sites of metachronous malignancies.
The incidence and sites of metachronous malignancies were retrospectively determined from the records of 763 patients seen at Yale University medical Center and affiliated hospitals with previously untreated, invasive carcinoma of the uterine cervix from 1953-1972. These patients were treated predominantly with radiation therapy; follow-up status was known for periods of 5-25 years or until time of death in over 96% of the patients. Forty-four patients had second malignancies noted at least 6 months after the initial cervical cancer was diagnosed. The expected incidence of second malignancies was determined from the Connecticut State Tumor Registry data controlling for year of diagnosis of the cervical cancer, patient age, sex, and time at risk (person-years exposure). To correct for any error in estimation of second malignancies introduced by the existence of a latency period for the development of a second cancer, the expected incidence of malignancies was also computed for 5-year time intervals following the cervical cancer. No significant increase in second malignancies was found (observed/expected-44/36) for the entire follow-up period nor for any individual 5-year interval. However, a statistically significant increase in lung cancer and vulva-vaginal cancer was noted and a significant decrease in breast cancer was observed. Cox regression analyses were performed to study the effect of total radium exposure and total external beam treatment, adjusting for other factors. No statistically significant increased risks were found.