3439 - Is Time of the Essence? Site-Specific Impact of Induction Chemotherapy-to-Radiation Interval Length on Outcomes for Locally Advanced Head and Neck Cancer (LA-HNC)
Presenter(s)
E. Chang1, A. Khodab2, P. T. Fair3, C. Gui4, T. Laufer4, B. R. Page5, H. Quon6, and C. Kut5; 1Johns Hopkins School of Medicine, Baltimore, MD, 2University of South Carolina School of Medicine Columbia, Columbia, SC, 3Johns Hopkins University School of Medicine, Baltimore, MD, 4Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, 5Johns Hopkins University Department of Radiation Oncology, Washington, DC, 6Johns Hopkins University Department of Radiation Oncology, Baltimore, MD
Purpose/Objective(s):
Induction chemotherapy (IC) added to chemoradiotherapy (CRT) can improve treatment outcomes in LA-HNC, ranging from improved survival for patients with nasopharyngeal cancers to organ preservation in laryngeal cancers. IC is also sometimes recommended for patients with oropharyngeal cancer for large (T4) or bulky nodal disease. However, the optimal interval between IC and CRT is poorly understood. This contrasts with surgically managed HNC where shorter time to RT after surgery was associated with improved survival outcomes. Here, we explore the association between induction-to-radiation (ITR) interval and survival outcomes in patients with LA-HNC.Materials/Methods:
We performed a retrospective cohort study of patients with newly diagnosed LA-HNC of the larynx, nasopharynx, or oropharynx treated with IC followed by CRT or RT alone at our institution between 2008 & 2025. Tumor sites were stratified by interval length, and overall survival (OS) and progression-free survival (PFS) were compared by Kaplan-Meier survival analysis.Results:
86 patients were identified (73% male, age at diagnosis was 60 ± 14 [SD]). Primary tumor subsites were 28% laryngeal, 37% nasopharyngeal, and 35% oropharyngeal. Most patients had stage IV disease (80.5%), with primarily T4 (55.3%) and/or N1 (27%) or N2 (54.3%) disease. The most common IC regimens were a platinum agent combined with paclitaxel, cetuximab and/or pembrolizumab for larynx (83.9%) and oropharynx sites (86.3%). At the nasopharynx, most patients received gemcitabine and cisplatin (56%), though other systemic therapies were used prior to 2019. Median induction-to-radiation intervals (ITR) were similar across subsites. For larynx and nasopharynx primaries, median ITR was 29 days with IQR [14, 37] and [22, 43] respectively. For oropharynx, median ITR was 22 days [8, 33]. Median [IQR] follow-up duration was 4.1 [1.36, 4.98], 2.3 [2.05, 3.94], and 5.9 [2.43, 9.88] years for larynx, nasopharynx, and oropharynx. 1-year OS was 83%, 90% and 89% at the larynx, nasopharynx and oropharynx subsites. 1-year PFS was 70%, 73% and 83%, respectively. 3-year OS was 49% and 82% for the larynx and oropharynx subsites, and 3-year PFS was 37% and 67%, respectively. 3-year OS and PFS were not reported for nasopharynx due to small sample size and shorter follow up duration. When stratified by ITR length, there was no significant difference in 1-year or 3-year OS or PFS comparing ITR above vs. below the median at any subsite.Conclusion:
ITR length did not appear to impact OS or PFS at any subsite. External validation with a larger dataset in a multi-institutional setting is needed to better evaluate the impact of ITR on survival outcomes.
| 1 year OS (%) | 3-year OS (%) | 1-year PFS (%) | 3-year PFS (%) | ||
| Larynx (n = 24) | ITR = 29 days | 83 | 53 | 75 | 33 |
| ITR > 29 days | 82 | 45 | 65 | 46 | |
| p-value | 0.95 | 0.72 | 0.61 | 0.50 | |
| Nasopharynx (n = 32) | ITR = 29 days | 88 | - | 58 | - |
| ITR > 29 days | 92 | - | 93 | - | |
| p-value | 0.70 | - | 0.01 | - | |
| Oropharynx (n = 30) | ITR = 22 days | 87 | 80 | 74 | 74 |
| ITR > 22 days | 92 | 85 | 92 | 56 | |
| p-value | 0.59 | 0.73 | 0.15 | 0.35 |