3451 - Patterns of Failure and Salvage Treatment Outcomes in Locoregionally Advanced Head and Neck Squamous Cell Carcinoma Following Definitive Chemoradiation
Presenter(s)
P. Dalwadi1, R. Harbison2, R. S. Jackson3, P. Pipkorn4, S. Puram4, J. Rich3, B. Wahle5, P. Zolkind6, D. Adkins7, C. Auberle8, B. Knapp9, P. Oppelt10, J. Zaretsky6, A. J. Apicelli III11, J. F. De Los Santos12, H. A. Gay13, S. D. Karam14, W. L. Thorstad15, and N. Rammohan16; 1Washington University/B-JH/SLCH Consortium, St. Louis, MO, 2WashU Medicine, Saint Louis, MO, 3WashU Medicine, St. Louis, MO, 4Department of Otolaryngology, Washington University School of Medicine in St. Louis, St. Louis, MO, 5Washington University in St. Louis, Saint Louis, MO, 6Washington University, Saint Louis, MO, 7Washington University School of Medicine in St Louis, St. Louis, MO, United States, 8Washington University School of Medicine, Saint Louis, MO, United States, 9Washington University School of Medicine in St Louis, St. Louis, MO, 10Department of Medicine, Division of Oncology, Washington University School of Medicine in St. Louis, St. Louis, MO, 11VA St. Louis Health Care System, Saint Louis, MO, 12Washington University in St Louis, Department of Radiation Oncology, St Louis, MO, 13WashU Medicine, Department of Radiation Oncology, St. Louis, MO, 14Department of Radiation Oncology, University of Colorado, Aurora, CO, 15Department of Radiation Oncology, Washington University School of Medicine in St. Louis, St. Louis, MO, 16Department of Radiation Oncology, Alvin J. Siteman Cancer Center at the Washington University School of Medicine, Saint Louis, MT
Purpose/Objective(s): There is limited data regarding salvage therapy outcomes of head and neck squamous cell carcinoma HNSCC that failed primary definitive radiation therapy. In this study we characterize recurrence patterns and evaluate salvage treatment efficacy in locoregionally advanced HNSCC following definitive radiation therapy.
Materials/Methods: Retrospective review of patients with locoregionally advanced HNSCC treated with definitive intensity-modulated radiation therapy (IMRT) with or without systemic therapy from 2017–2024. Biopsy-confirmed recurrences were classified relative to prior radiation treatment volumes. Successful salvage was defined as a disease-free interval of =1 year post-salvage therapy. Survival and salvage outcomes were analyzed with Kaplan-Meier methods.
Results: 230 patients were included with majority male (85%) and median age of 63 years. Primary sites of disease were oropharynx (86%), hypopharynx/larynx (9%), nasopharynx (5%), and unknown primary (3%). 57% had T3+ and 94% had N2+ disease; 69% were p16+. Median follow-up was 30.3 months (IQR 15.6-53.8 months). Two-year overall survival (OS) was 89.3%; median OS was 46.5 months (IQR 25.2-74.3 months). Two-year local control (LC) was 70.9%. Among p16+ patients, 49/173 (28.3%) recurred: 11 isolated locoregional (LR), 28 isolated distant, and 10 both. Among p16- or unknown patients, 30/76 (39.5%) recurred: 14 isolated LR, 10 isolated distant, and 6 both. Most LR failures occurred in-field, including 9/25 (36%) involving both primary site + neck and 8/25 (32%) in the neck-only; only one patient failed locoregionally outside the irradiated volume. Of patients who underwent salvage therapy (N=77), successful salvage occurred in 19 patients (24.7%). Of patients with neck only failures 6/9 (66.6%) were salvaged by surgery (N=3), surgery + RT (N=2), and systemic therapy (N=1) respectively. Of patients with primary + neck failures, 4/9 (44.4%) were salvaged with systemic therapy (N=2), surgery + RT (N=1), and RT + systemic therapy (N=1) respectively. No patients with primary-only (N=4), and combined LR + distant failures (N=19) were successfully salvaged. Of the isolated distant failures, 9/38 (23.7%) were salvaged with systemic therapy (N=6), surgery (N=1), surgery + systemic therapy (N=1), and surgery + RT (N=1) respectively.
Conclusion: Definitive radiation therapy achieved favorable local control and survival, with most recurrences arising within the high-dose irradiated volume. Approximately half of locoregional failures were able to be salvaged, where neck-only failures demonstrated the greatest salvage potential. While a small proportion of isolated distant metastases were salvaged, distant relapse remained the main determinant for poor outcome.