Incidence of Vaginal Intraepithelial Neoplasia After Hysterectomy for Cervical Cancer or Cervical Intraepithelial Neoplasia: A Systematic Review and Meta-analysis.

To investigate the incidence of vaginal intraepithelial neoplasia (VAIN) 1+ in patients after hysterectomy for cervical intraepithelial neoplasia (CIN) or cervical cancer. A systematic search was conducted in PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials from inception to January 2025. 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+. 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. 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. PROSPERO, CRD42023433781.