Multicentricity and the Risk of Recurrence/Persistence After Laser Vaporization for High-Grade Vulvar and Vaginal Intraepithelial Neoplasia.

Background: The aim of the study was to assess the effect of multicentricity on the recurrence/persistence of high-grade vulvar intraepithelial neoplasia (VIN) and vaginal intraepithelial neoplasia (VAIN) after laser vaporization.

Methods: A retrospective cohort study was conducted on patients diagnosed with high-grade VIN/VAIN, who had undergone laser vaporization between 1997 and 2014. Recurrence/persistence rates and factors affecting recurrence/persistence were analyzed, and a life table analysis of recurrence-free intervals was conducted.

Results: Among the 65 patients, the recurrence/persistence rate following laser vaporization was 22.3 per 100 person-years, with a median time to recurrence/persistence of 31.2 months (95% confidence interval (CI): 0.0 - 71.9 months). Patients with multicentricity and unicentricity had a recurrence/persistence rate of 49.1 per 100 person-years, with a median time to recurrence/persistence of 11.4 months, and 7.4 per 100 person-years, with a median time to recurrence/persistence of 96.5 months, respectively (P = 0.0002). The difference in recurrence-free survival between the multicentricity and unicentricity groups was significant (P = 0.00035). Patients with multicentricity had a 4.7-fold higher risk of recurrence/persistence (hazard ratio (HR): 4.71, 95% CI: 1.87 - 11.88, P = 0.001). Multivariate analysis showed that multicentricity was an independent risk factor for recurrence/persistence (odds ratio (OR): 4.16, 95% CI: 1.56 - 11.06, P = 0.004).

Conclusions: Treatment of multicentric, high-grade VIN/VAIN with laser vaporization is strongly associated with treatment failure, with approximately half of patients experiencing recurrence/persistence.