Main Session
Sep 28
PQA 04 - Breast Cancer, Patient Reported Outcomes/QoL/Survivorship, Functional Radiation Medicine, Hematologic Malignancies, Palliative Care, and International/Global Oncology

2708 - Patient Reported Outcomes in Oropharyngeal Cancer Treated with Cisplatin vs. Carboplatin+Paclitaxel in Combination with Definitive Intensity-Modulated Proton Therapy

03:00pm - 04:00pm ET
Poster Hall - Exhibit Hall A
Screen: 27
POSTER

Presenter(s)

Matthew Case, MD - Emory University, Atlanta, GA

M. J. Case1, K. Luca1, J. E. Bates1, J. S. Remick1, A. Jethanandani1, D. M. Shin2, N. F. Saba2, and W. A. Stokes1; 1Department of Radiation Oncology, Winship Cancer Institute of Emory University, Atlanta, GA, 2Department of Hematology and Medical Oncology, Winship Cancer Institute of Emory University, Atlanta, GA

Purpose/Objective(s): While cisplatin (Cis) remains the preferred radiosensitizer in definitive chemoradiotherapy for oropharyngeal cancer (OPC), carboplatin+paclitaxel (C+P) has emerged as an alternative in patients medically unfit for cisplatin. While comparisons of oncologic endpoints and clinician-assessed toxicities between Cis and C+P have been performed, differences in patient-reported outcomes (PROs) are poorly understood. Due to its potential to decrease dose to nontarget tissues and reduce radiotherapy-related toxicity, intensity-modulated proton therapy (IMPT) offers a suitable backbone for comparing radiosensitizer regimens. This study compares PROs between Cis vs C+P added to definitive IMPT for OPC.

Materials/Methods: OPC patients treated at our institution (2018-2024) receiving definitive IMPT with either weekly Cis (40mg/m2) or C+P (AUC 2 & 45-60mg/m2) were retrospectively reviewed. Patients were prompted to complete the MDASI-HN at baseline, weekly during IMPT, and at 1 and 3 months post-IMPT. Cases missing baseline or 3-month scores were excluded. Interior missing data points were filled by linear interpolation. MDASI-HN score was calculated as the mean of all 22 subscores (each scored 0-10; higher scores indicate worse PROs). MDASI Radiation Symptom Severity (MDASI-RSS) score was calculated as the mean of 9 radiation-related subscores. To provide longitudinal depiction of PROs in the acute period, MDASI-HN, MDASI-RSS, and all 22 subscores were assessed as AUC (score x weeks) from baseline to 3 months post-IMPT and compared between Cis and C+P cohorts via Mann-Whitney U test. Recurrence rates were also compared.

Results: Of 98 OPC patients included (68 Cis and 30 C+P), median follow-up was 23.5 months (IQR 11-38) and did not significantly differ between groups (25 vs 20.5 months, p=0.27). The C+P cohort was older (mean 70.9±5.8 vs 61.2±9.6, p<0.01) and exhibited worse performance status (p=0.02). There were no significant differences in AJCC 8th edition clinical stage, primary site, smoking status, or unilateral vs bilateral neck radiation. There were no significant differences in AUC between Cis and C+P for either MDASI-HN (median 47 vs 55, p=0.21) or MDASI-RSS (median 45 vs 54, p=0.22). On subscore analysis, the C+P group reported significantly worse skin toxicity (median 20 vs 39, p<0.01) and memory difficulty (median 28 vs 46, p=0.03); the remaining subscores were not significantly different. There were no significant differences in locoregional (94.1% vs 96.7%, p>0.99) or distant control (89.7% vs 96.7%, p=0.43).

Conclusion: Despite older age and worse performance status in the C+P cohort, there were no significant differences in composite PRO scores or recurrence risk between patients treated with Cis vs C+P. These findings support the use of C+P as an alternative radiosensitizer in Cis-ineligible patients.