Introduction/Background Vulval intraepithelial neoplasia (VIN) is a premalignant lesion. The incidence of VIN is increasing and is estimated to be 3.8 per 100,000 women-years. This 15-year retrospective institutional study of treated VIN informs on recurrence rates, risk factors for recurrence following various treatment modalities.

Methodology Retrospective study of primary treatment and outcomes for VIN at CUH from 2008 to 2022. A total of 88 patients from the pathology database and 20 patients from the vulval clinic were grouped according to initial treatment modality.

Results The median age of the cohort was 51 (CI 50.2 – 55.0) years. Median follow-up time was 45 (CI 40 – 57) months. 4 groups were studied: Local excision with clear margins – n=26 with 5 recurrences at median 52 months - Multifocal disease (MFD) rate 19%, Local excision with positive margins – n=44 with 24 recurrences at median 23 months - MFD rate 50%, Laser – n=25 with 17 recurrences at median 26 months - MFD rate 64%, and Medical – n=13 with 7 recurrences at median 17 months - MFD rate 46%.

Conclusion Local excision achieving clear margins is associated with significantly lower risk of recurrence (p=0.003). Where margins are positive relapse rates are higher and occur earlier after initial treatment (50% vs 19%; p0.004 ). MFD is a risk factor for early recurrence (p=0.018). These patients are at high risk of recurrence and may require multimodal treatments and more intense follow up.

Disclosures No conflicts of interest to disclose.