Selective intra-arterial chemotherapy for locally advanced inoperable head and neck cancer: an analysis of long-term survival in an open prospective study

Patients with locally advanced inoperable head and neck cancer (HNC) have an unfavorable prognosis and a rapid fatal outcome with standard systemic chemotherapy and/or radiation therapy. The median overall survival(s) with traditional treatment does not exceed 12-16 months. Aim: to evaluate the long-term survival of patients and the effectiveness of selective intra-arterial chemotherapy (IAC) in locally advanced inoperable HNC. Material and methods. An open prospective study included 56 patients with locally advanced inoperable HNC (stage IVA-IVB) who received selective IAC using high doses of Cisplatin and other chemotherapy drugs selectively injected into the arteries feeding the tumor. The studied patients were stratified by tumor location (oropharynx, tongue, floor of the oral cavity, and other locations), the presence of lymphatic metastases, and concomitant pathology. The primary endpoint was an analysis of overall survival in the medium follow-up term (mean follow-up 39 months, range 10-221 months). The secondary endpoints were the tumor response to treatment, the safety of the procedure, and the quality of life. The initial cohort (n=56) was characterized by such indicators as age 59.8 ± 9.8 years (41-81), men 84.8% (n=47), women 15.2% (n=9). The main risk factors included smoking (69.7%, n=39), hypertension (93.9%, n=52), type 2 diabetes mellitus (90.9%, n=51), and atherosclerosis of the brachiocephalic arteries (54.5%, n=30). The average comorbidity was 3.1 ± 0.7 risk factors per patient, reflecting the age and severity of the population. The localization of the primary tumor is represented by the oropharynx (24.2%), tongue (21.2%), bottom of the oral cavity (15.2%), and other localizations (39.4%). The presence of metastases to regional lymph nodes was detected in 51.5% of patients (n=28). The majority of patients (90.9%, n=51) received one SHIFT procedure, the minority (9.1%, n=5) received two or three procedures. Results. Of the 56 initially enrolled patients, 33 patients are alive at the time of writing (end of 2025) (58.9%, 95% CI: 44.7–72.6). This is a significantly higher value compared to the expected survival rate with standard treatment, in which this indicator does not exceed 15-20% after 24-39 months. The average tumor response to treatment was 7.9 ± 5.4 according to the surrogate effect index (range: 3.2–31.9). The incidence of complications was low (12.1%, n=4), and included mucosal edema (n=1), hyper-salivation (n=1), contrast leakage into neighboring structures (n=1), scratching, and a feeling of lack of air (n=1). No deaths directly related to the WATCH procedure were recorded. Conclusion. Selective intra-arterial chemotherapy is an effective and safe treatment method for patients with locally advanced inoperable head and neck cancer, significantly improving long-term survival and quality of life compared to standard treatment. The results of the study confirm the need to introduce this method as a standard approach in the treatment of inoperable forms of HNC in specialized institutions.