Cost-minimization analysis of the GORTEC 2014-04 randomized phase II study of stereotactic ablative radiotherapy (SABR) or chemotherapy-SABR in oligometastatic head and neck cancer.

Purpose: The randomized phase II GORTEC 2014-04 and French Head and Neck Intergroup study showed deeper deterioration of the quality of life (HRQoL) and dramatically higher severe toxicity rates with similar overall survival rates using chemo-SABR compared to SABR alone in oligometastatic head and neck cancer (HNSCC) patients. We evaluated the costs associated with SABR-alone versus chemo-SABR and their associated costs (transportation, hospitalizations, etc).

Materials and methods: 69 HNSCC patients with 1-3 oligometastases and a controlled primary were randomized from September 2015 to October 2022. HRQoL by the QLQ-C30, QLQ-HN35, descriptive EQ5D-3L and visual EQ-VAS self-rated questionnaires were completed for clinical benefit and economic utility appraisal. Direct medical treatment-related costs (radiotherapy, anticancer drugs, hospital stays, serious adverse event management, medical imaging, biological surveillance and medical transports) were analyzed from randomization until 12 months (M12, including per protocol and salvage treatments) or death. Utility index scores and deterioration rates were used. Based on equivalent outcomes, a cost-minimization analysis was performed..

Results: Median EQ-5D-3L utility index scores were 0.84 at baseline and 0.87 at M12 for SABR-alone; corresponding to 0.85 and 0.57 for chemo-SABR. Rates of patients free of definitive EQ-VAS deterioration at M12 were 76.9 % and 63.8 % for SABR-alone and chemo-SABR. Mean quality-adjusted PFS was 12.1 and 11.0 months with SABR-alone and chemo-SABR. The mean total costs from the French Public health system perspective were €8,498 ± 3,599 for SABR-alone, and €48,034 ± 58,228 for chemo-SABR (p < 10^-4). Sensitivity analyses confirmed cost savings around €35,000-€40,000 per patient using SABR-alone. Anticancer drugs and hospital stays were cost drivers. The economic burden increased by 269 ± 66 % with chemo-SABR compared to SABR-alone (p < 10^-4).

Conclusions: in addition to clinical benefits, SABR-alone appears as the least costly option (by a factor of 5) for the management of oligometastases from HNSCC.