2837 - Trends in Utilization of Locoregional Radiotherapy for De Novo Metastatic Nasopharyngeal Carcinoma

10:45am - 12:00pm PT

Hall F

Screen: 22

POSTER

Presenter(s)

Lokesh Seth, MD, MS - Piedmont Macon GA, Roswell, GA

L. Seth¹, J. Weng², S. Maroongroge³, A. L. Schwer², S. Sampath³, A. Shreenivas⁴, S. Kollimuttathuillam⁵, D. Nguyen⁵, G. Semeniuk⁵, K. Patel⁶, T. Gernon⁶, E. Maghami⁶, A. Amini³, and C. J. Ladbury^2,3; ¹Ross University School of Medicine, Iselin, NJ, ²Department of Radiation Oncology, Orange County Lennar Foundation Cancer Hospital, Irvine, CA, ³Department of Radiation Oncology, City of Hope National Medical Center, Duarte, CA, ⁴Department of Medical Oncology & Therapeutics Research, City of Hope National Medical Center, Duarte, CA, ⁵Department of Medical Oncology & Therapeutics Research, Orange County Lennar Foundation Cancer Hospital, Irvine, CA, ⁶Department of Surgery, City of Hope National Medical Center, Duarte, CA

Purpose/Objective(s): Based on data published in 2020, locoregional radiotherapy (RT) with chemotherapy has been shown to improve overall survival in patients with de novo metastatic nasopharyngeal carcinoma (mNPC). It is recommended as part of National Comprehensive Cancer Network guidelines. However, the uptake of these data and guidelines is uncertain. This study sought to characterize the utilization of RT for mNPC using a large national cancer database. The hypothesis was that the utilization of RT for mNPC increased following the publication of supporting data in 2020.

Materials/Methods: We conducted a retrospective analysis using the National Cancer Database for patients with mNPC diagnosed between 2017-2022. Patients who had unknown clinical T or N staging, underwent primary surgery, or were missing radiation details were excluded. Patients who underwent radiation only to sites other than the head and neck region (i.e. metastatic lesions) were also excluded. Trends in the use of RT to the primary were assessed using temporal trends and multivariable (MVA) logistic regression.

Results: A total of 685 patients met the inclusion criteria, with 349 (50.9%) receiving RT. In contrast, 525 (76.6%) received chemotherapy. Median age was 58 (IQR: 49-68) and 73.3% were male. Of the patients who received RT, 304 (87.1%) received concurrent chemotherapy. In 2017, 46.8% of patients received RT. This rate subsequently peaked in 2020 at 61.5% but then dropped to 42.7% in 2022. Among the reasons listed for RT not being given, in 81.8% of cases it was not part of the planned first course of treatment. In 8.9% of cases, RT was recommended but not delivered due to patient refusal. On MVA, white race (Ref: Non-white, OR: 1.37, p=.059), private insurance (Ref: Government, OR: 1.67, p=.004), and income =$63k (Ref: <$63k, OR: 1.46, p=.050) were associated with receipt of RT. Increasing T (T4 vs T1, OR: 2.43, p<.001) and N (N3 vs N0, OR: 2.08, p=.016) stage were also associated with receipt of RT. With regards to the impact of the specific metastatic site, the presence of distant nodal (OR: 0.68, p=.062), bone (OR: 0.57, p=.001), liver (OR: 0.56, p=.002), and lung (OR: 0.58, p=.004) metastasis were associated with decreased utilization of RT. Year of diagnosis, age, sex, ethnicity, Charlson-Deyo score, hospital type, facility volume, and presence of brain metastasis were not significantly associated with receipt of RT.

Conclusion: Despite an overall survival benefit to RT for de novo mNPC, nearly one-half of patients did not receive this recommended treatment, with no apparent improvement in rates since the publication of the corresponding landmark trial in 2020. Though locoregional radiotherapy may not be suitable for all patients, future work is warranted to investigate the cause of underutilization and identify means of overcoming barriers to receiving guideline-concordant care.