EP1170 Development of a risk model for survival and recurrence in patients with vulvar squamous cell carcinoma

Introduction/Background Increasing evidence points to better prognosis for human papillomavirus (HPV)-positive vulvar squamous cell carcinoma (HPVposVSCC) compared to HPV-negative VSCC (HPVnegVSCC). The aims of this study were to evaluate the clinical significance of HPV and other prognostic factors in a large cohort with VSCC patients and to develop risk models for survival and recurrence. Methodology Patients with primary VSCC, surgically treated with curative intent between 2000 and 2015 (n=421) were included. HPV was determined by HPV-PCR and p16 immunohistochemistry. Overall survival (OS), relative survival (RS), and recurrence-free period (RFP) were determined in patients with HPVposVSCC and HPVnegVSCC. A risk model based on prognostic factors with significant impact on OS and RFP was designed to predict risk of death and shorter RFP. Data were internally validated using a bootstrap resampling procedure. Results Patients with HPVnegVSCC had worse 5-year OS, RS, and RFP than those with HPVposVSCC (52%, 64%, and 46% vs 82%; p=0.001, 90%; p=0.010, and 82%; p Conclusion The developed risk models contribute to better prediction of survival and recurrence in surgically-treated VSCC patients. They may aid trial design and encourage the selection of high-risk patients potentially benefitting from new therapies or intensified follow-up. Disclosure Nothing to disclose