Incidence of Vaginal Intraepithelial Neoplasia After Hysterectomy for Cervical Cancer or Cervical Intraepithelial Neoplasia

OBJECTIVE: To investigate the incidence of vaginal intraepithelial neoplasia (VAIN) 1+ in patients after hysterectomy for cervical intraepithelial neoplasia (CIN) or cervical cancer. DATA SOURCES: A systematic search was conducted in PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials from inception to January 2025. METHODS OF STUDY SELECTION: We identified 7,234 studies, 48 of which were included in the meta-analysis. The primary outcome was the incidence of pathologically confirmed VAIN 1+ (VAIN 1, 2, or 3 or vaginal cancer) in patients after hysterectomy for CIN or cervical cancer; the secondary outcome was the clinicopathologic characteristics of these patients. Single-proportion meta-analysis was performed to estimate the incidence and 95% CIs of VAIN 1+. TABULATION, INTEGRATION, AND RESULTS: A total of 18,959 patients who underwent hysterectomy for CIN or cervical cancer were included. The overall pooled incidence of VAIN 1+ was 2.7% (95% CI, 1.8-3.7%). The incidences of VAIN and vaginal cancer were 2.7% (95% CI, 1.7-3.7%) and 0.3‰ (95% CI, 0.0-1.0‰), respectively. The incidence of VAIN increased gradually in more recent studies compared with studies published before 2000. CONCLUSION: Nearly 3 of every 100 women develop VAIN 1+ after hysterectomy for CIN or cervical cancer. The rate of vaginal dysplasia has significantly increased over time. SYSTEMATIC REVIEW REGISTRATION: PROSPERO, CRD42023433781.