2796 - Tailoring Surgery to Radiotherapy Response in T4b Sinonasal Squamous Cell Carcinoma: A Multicenter Study
Presenter(s)
Q. Liu1, and J. Luo2; 1Department of Radiation Oncology, Mayo Clinic, Rochester, MN, 2Department of Radiation Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
Purpose/Objective(s): The prognosis of T4b Sinonasal squamous cell carcinoma (SNSCC) remains poor, necessitating multidisciplinary approaches to improve patient outcomes. This study evaluated the efficacy of the response-adapted strategy in patients with T4b SNSCC.
Materials/Methods: This retrospective study enrolled consecutive patients with T4b SNSCC treated at three tertiary academic medical centers between January 1999 and January 2019. Patients received radiotherapy and were then divided into response and non-response groups according to whether achieving objective response after radiotherapy. Subsequently, patients received either surgery or best supportive care (BSC). The endpoints included overall survival (OS), locoregional relapse-free survival (LRFS), and distant metastasis-free survival (DMFS).
Results: Among 134 eligible patients, 98 (73%) achieved objective responses, while 36 (27%) did not. The median follow-up time was 74.74 months. In the response group, surgery significantly improved 5-year OS (56.6% vs. 28.8%, p < 0.001), LRFS (51.7% vs. 20.8%, p = 0.002), and DMFS (54.9% vs. 26.9%, p < 0.001) compared to BSC. However, in the non-response group, no significant differences in OS, LRFS, or DMFS were observed between the surgery and BSC groups. Surgical complications were infrequent, even in the context of radiotherapy. Furthermore, patients who underwent surgery encountered fewer acute side effects related to radiation, mainly due to the lower radiation dose than those receiving the best supportive care (BSC).
Conclusion: For T4b SNSCC patients who responded to radiotherapy, surgery demonstrated a survival advantage over BSC; non-responders may not benefit from surgery. The strategy of radiotherapy response-adapted addition of surgery proved survival advantage and warranted prospective validation.