ESTRO 2023 - Abstract Book

S963

Digital Posters

ESTRO 2023

Conclusion In view of our results we can conclude that in patients undergoing radical or adjuvant re-irradiation treatment, time between first and second irradiation longer than two years, good performance status and doses higher than 50Gy improve results.

PO-1204 Racial Disparities in Survival for Human Papillomavirus Associated Oropharyngeal Cancer

S. Baliga 1 , D. Mitchell 1 , S. Jhawar 1 , D. Konieczkowsi 1 , J. Grecula 1 , D. Blakaj 1 , M. Gamez 1

1 The Ohio State University Wexner Medical Center, Radiation Oncology, Columbus, USA

Purpose or Objective Patients with Human papillomavirus (HPV)- associated oropharyngeal squamous cell carcinoma (OPSCC) have been shown to have a favorable prognosis and excellent overall survival. Racial/ethnic (R/E) minorities with head and neck squamous cell carcinoma (HNSCC) have worse survival outcomes compared to White patients. In this study, we aimed to determine whether racial disparities in survival exist in patients with HPV-associated OPSCC. Materials and Methods This was a population based retrospective cohort study that analyzed HNSCC patients using the National Cancer Database from 2010-2016. We identified patients with Stage I-IV HPV-associated OPSCC who were treated with radiation, surgery, chemotherapy, or a combination of modalities. Patient outcomes were stratified by R/E groups including White, Black, Asian, and Native American/Other. The main outcome in this study was overall survival (OS). Analyses for proportions of categorical variables were performed using a Chi-Square or Fisher's Exact test. The analysis of differences between race in continuous variables were tested using analysis of variance (ANOVA) or Kruskal-Wallis tests as appropriate according to distribution of residuals. Univariate time-to-event survival analyses were performed using Kaplan Meier product limit estimates and log-rank test to test the differences between strata. Results We identified 13,612 OPSCC patients, of which 1,750 were HPV positive (13%). Of the 1,750 HPV-OPSCC patients, 1,598 (91.3%) were White, 129 (7.4%) were Black, 9 (0.5%) were Native American/Other , and 14 were Asian (0.8%). Sixty-one patients presented with metastatic disease (3.81%). Compared to White patients, Black patients were more likely to be uninsured (8.5% vs 4.5%, p=0.04), have lower income (<$30,000, 36.5% vs 9.6%), and more likely to have metastatic disease (10% vs 3%, p=0.0004). The 5-year OS for HPV positive versus HPV negative OPSCC patients was 63.6% versus 33.6% (log rank, p<0.0001). Among HPV positive patients, the 5-year OS for White, Asian, and Black patients was 65.6%, 55%, and 39.4% (log-rank, p<0.0001). Among HPV negative patients, 5-year OS for White and Black patients was 36.5% versus 13.8%, respectively (log-rank, p<0.0001). Conclusion This large cohort study of OPSCC patients demonstrates that Black patients with HPV associated OPSCC have a poor prognosis and overall survival similar to HPV-negative White patients. This may be partly due to socioeconomic barriers such as insurance and income. Further work is needed to better understand the specific drivers of inferior survival outcomes in this patient population.

PO-1205 MRI changes in Muscles of Mastication during radiotherapy: secondary analysis of PREDICT-HN study