Recurrence free survival in patients with HPV+ head and neck cancer treated with TORS and neck dissection.

Abstract

e18076 Background: Prior research has demonstrated that delays to initiation of radiation therapy (RT) in the treatment of head and neck squamous cell carcinoma (HNSCC) after surgery result in poorer survival outcomes. However, there is limited data with little long-term follow up to evaluate whether human papilloma virus (HPV) positive primaries undergoing transoral robotic surgery (TORS) and neck dissection (ND) face a similar decrement in recurrence free survival (RFS) and disease specific survival (DSS). Methods: Single center retrospective chart review of patients diagnosed with HPV positive primary nonmetastatic HNSCC who underwent TORS with ND followed by RT with or without Chemotherapy and/or Immunotherapy from 2012-2022 with data collection from December 2022 to February 2023. 248 patients met inclusion criteria and were analyzed for DSS and RFS. Kaplan-Meier survival analysis with Log-rank testing was used to assess the impact of time intervals between diagnosis, TORS, radiation initiation and radiation completion on survival. Univariable and Multivariable Cox proportional hazards regression analysis was performed to identify factors associated with RFS and DSS and adjust for potential confounding variables. Subgroup analysis was completed with high risk (lymph nodes > 4 with extracapsular extension) and low risk population. Results: Median follow-up time was 47.22 months (1452.07 days). Of 248 patients, 17 had a recurrence and 12 died due to disease. In patients who underwent radiation therapy for a time frame (TR1-R2) of 5-7 weeks compared with those who had a shortened or prolonged course of RT, RFS (140.116 months, p-value = .012) and DSS (142.641 months, p-value = .016) were improved. Although time from diagnosis to TORS did not impact RFS (p-value = .195), improved RFS persisted in patients who underwent time from diagnosis to radiation completion (TD-R2) or total treatment package time (TTPT) between 17-20 weeks (109.155 months, 95% CI: 105.276-113.034, p-value = .057) compared to patients with TTPT less than 17 or greater than 20 weeks. When the population is stratified into high risk and low risk groups, patients in the high risk group who underwent Chemotherapy had improved RFS compared to no chemotherapy (HR: 7.19, p-value = .09). On Univariate Analysis, TR1-R2 < 5 weeks and > 7 weeks, TD-R2 < 17 weeks and > 20 weeks, extracapsular extension, smoking history, and age > 70 were associated with increased risk of recurrence. Conclusions: For HPV positive patients with OPSCC undergoing TORS and Neck dissection, time to radiation initiation may not be as critical in improving OS, DSS, and RFS as other patient populations. However, the length of radiation time between 5 to 7 weeks and overall treatment time from 17-20 weeks may improve recurrence free survival and disease specific survival.