The effectiveness of neoadjuvant chemotherapy prior to proton beam therapy for head and neck tumors

BACKGROUND: Malignant tumors of the head and neck are a significant problem in modern oncology, as they occupy an important place in the structure of morbidity and mortality of the population. According to the Ministry of Health of the Russian Federation, 674,587 new cases of malignant neoplasms were registered in 2023, of which 25,038 cases were tumors of the head and neck. AIM: of the study was to evaluate the effect of induction drug therapy on the treatment outcomes of patients with locally advanced tumors of the head and neck who received radiation treatment using proton therapy, IMPT technique (intensity modulated proton therapy). METHODS: The retrospective study included an analysis of the medical records of 103 patients with head and neck tumors, who were divided into two groups: patients who received induction chemotherapy followed by proton chemoradiotherapy (n=50), and patients who did not receive induction antitumor treatment before starting proton chemoradiotherapy (n=53). T-tests for independent samples were used to assess differences between patient groups. The statistical significance of the differences was considered at a level of p <0.05. RESULTS: The median follow-up was 13.4 months (IQR: 11.6–21.6 months). The average follow-up time was 15.7±7.8 months. In the group of monitored patients, none interrupted planned treatment, and therapy was completed on time. In the induction chemotherapy followed by proton chemoradiation therapy group, the average OS was 27.65 months (95% CI: 24.46–30.85), while for the proton chemoradiation therapy groups it was 27.27 months (95% CI: 22.15–31.72), which was a statistically insignificant difference (Chi-squared 0.776, p=0.378). The median OS for both study groups was not reached. The progression-free survival assessment showed that the average time to progression in the induction chemotherapy followed by proton chemoradiation therapy group was 23.1 months (95% CI: 19.6–26.6), versus 21.2 months (95% CI: 16.7–25.7) in the proton chemoradiation therapy group. The incidence of grade 1 leukopenia was 30% in the induction chemotherapy followed by proton chemoradiation therapy group versus 20.8% in the proton chemoradiation therapy group, the incidence of grade 3 disorders was 26% in the induction chemotherapy followed by proton chemoradiation therapy group and 11.3% in the proton chemoradiation therapy group, and grade 3 complications were noted only in the induction chemotherapy followed by proton chemoradiation therapy group (12%). These differences are statistically significant (p <0.01). CONCLUSION: This study demonstrated that induction chemotherapy does not improve overall survival and progression-free survival in patients with locally advanced squamous cell carcinoma of the head and neck receiving proton chemoradiotherapy.