Vulvar intraepithelial neoplasia: Risk factors for recurrence.

Objective: We studied a large population of women with high-grade vulvar intraepithelial neoplasia (VIN) in order to identify patient and treatment-related risk factors for recurrence and progression to cancer.

Methods: For this retrospective cohort study of women with a histologic diagnosis of VIN within Southern California Permanente Medical Group between 1995 and 2007 medical records were reviewed; clinical, demographic and pathologic data were collected. Statistical analyses included Chi-squared and Student's t-tests, univariate and multivariate logistic regression, and cumulative incidence analysis.

Results: 914 patients with high-grade VIN were identified; 784 met inclusion criteria. We found 26.3% recurrences among treated women, with 2.2% progression to cancer (8.2% among those with recurrence). Risk factors for recurrence on multivariate analysis were: age >50years (OR, 1.44; 95%CI 1.01-2.07), immunosuppression (OR 2.08; 95%CI 1.42-3.06), metasynchronous VAIN or CIN (OR 1.76; 95%CI 1.08-2.88) in addition to margin status (OR 8.17; 95%CI 4.60-14.51) and adjacent LSA (OR 9.91; 95%CI 1.53-31.32) or HPV (OR 2.15; 95%CI 1.13-3.37) with excisional treatment. Recurrence rates did not differ significantly by smoking status and treatment modalities. Median time to recurrence was 16.9months; 25% had late recurrences (44-196months). Cumulative incidence analyses of time to recurrence shows a significantly higher risk among patients over age 50 (log-rank p=0.0031).

Conclusion: We identified independent risk factors for recurrence including age >50years, immunosuppression, metasynchronous vaginal or intraepithelial neoplasia, positive excision margins, and adjacent lichen sclerosus or human papilloma-virus. Regardless of treatment modality, 25% of recurrences occurred late, highlighting the need for long-term surveillance in women treated for VIN.