Is hysterectomy a risk factor for vaginal cancer?

Several recent case series have called attention to a possible association between previous hysterectomy and the subsequent development of vaginal cancer. To study this relationship, we compared 49 patients with vaginal cancer with 49 controls matched for age, race, and prior cervical dysplasia or neoplasia. Patients and controls were alike in terms of exposure to estrogens. Twenty-four patients (49%) had had prior hysterectomies, of which 13 (27%) were for benign disease. Similarly, 24 controls had a history of a hysterectomy. The matched-pairs odds ratio relating prior hysterectomy to vaginal cancer was 1.00 based on these data, with a 95% confidence interval of 0.47 to 2.12. In the subsample of women without a history of cervical disease, a similar odds ratio appeared. Although the study sample size did not permit exclusion of a twofold increase in risk, the statistical power to detect an actual odds ratio of 2.5 is 76%. At this level of statistical power, our data suggest that hysterectomy has a low probability of being a risk factor for vaginal cancer when age and cervical disease are controlled for. In the absence of such a relationship, screening for vaginal cancer does not appear to be necessary for women who have had a hysterectomy for benign disease.