A two-phase study investigating the quality of life benefit of additional 0.5% cocaine mouthwash to institutional standard of care mucositis management in head and neck cancer patients undergoing radiotherapy or chemoradiotherapy.

BACKGROUND: Mucositis remains a challenging complication of radiotherapy or chemoradiotherapy (CRT) for head and neck cancer (HNC) patients. There is limited data on the safety or effectiveness of cocaine mouthwash to treat mucositis. METHODS: This was single centre, prospective sequential cohort study in HNC patients undergoing CRT. Patients were allocated to the standard of care mucositis management (SOC) or SOC + 0.5% CMW (CMW). We assessed the benefit of CMW in the management of mucositis on patient reported quality of life (QoL) using the EORTC QLQ-C30 and H&N35 questionnaires at baseline, during CRT, at 1- and 3-months follow-up. RESULTS: Of 137 eligible patients,64 were included in each arm. Baseline characteristics were similar between the arms. Most patients were male (84%) who received 70 Gy of radiation (71%) with concurrent systemic therapy (74%). Up to 69% of patients had grade 2 or 3 mucositis and up to 78% of patients required prescription for opioid analgesia, but no consistent or clinically meaningful differences were observed between the arms. Morbidity was high without significant differences observed between SOC and CMW with high hospitalisation rates (49%) and need for enterostomy feeding (29%). There were significantly more patients with > 5% weight change from baseline to 3-months post treatment in the SOC (56.3% vs. 40.6%, p = 0.024). Rate of opioid analgesia prescription were not consistently different between the arms. No significant differences were observed in patient reported QoL between SOC and CMW (adjusted and unadjusted), or when assessed using a 10-point clinically meaningful difference threshold (p > 0.05). CONCLUSION: In HNC patients undergoing CRT, the addition of CMW to SOC management did not demonstrate any patient reported quality of life improvement or harm. TRIAL REGISTRATION: The study was retrospectively registered with the Australian New Zealand Clinical Trials Registry (ACTRN12625000158460) on 11 February 2025.