Effectiveness and tolerance of electrochemotherapy as palliative therapy for patients with head and neck cancer and malignant melanoma and its relation to early skin reaction

Abstract

Objectives: To evaluate the efficacy and tolerance after the electrochemotherapy treatment for local therapy of cutaneous and subcutaneous metastases of head-and-neck tumors and malignant melanoma refractory to standard therapies, mainly in neck metastasis of squamous cell carcinoma. And, to evaluate the relation of this response according to the skin reaction (healing with ulcer or dry crust).

Methods: prospective pase II, observational clinical study of 56 patients with metastases of head-and-neck squamous cell carcinoma (n=13), papillary thyroid carcinoma (n=4), adenoid cystic carcinoma of parotid gland (n=1) or malignant melanoma (n=37, 5 in head). Patients were treated by electrochemotherapy (application of electrical pulses into the tumor) after the administration of a single intravenous dose of bleomycin. Kaplan-Meier curves were performed. The statistical significance was evaluated using log-rank test; p-value of less than 0.05 was considered as significant.

Results: Overall clinical response was observed in 47 patients (84%). Local side effects were mild in all the patients. Ten patients (76.9%) with neck metastasis of squamous cell carcinoma had some degree of response, but only in one was complete. Patients even with only partial response had a higher overall survival than patients without response (p= 0.02). Most of the patients with squamous cell carcinoma had diminution of pain and anxiety. Response rate and overall survival was higher in MM patients (86.5%) than in squamous cell cancer patients (76.9%) (p= 0.043). The healing process (dry crust/ulcer) was not associated with the overall survival (p= 0.86).

Conclusions: Electrochemotherapy is associated a higher overall survival and diminution of pain and anxiety. Therefore, it is an option as palliative treatment for patients with neck metastasis of squamous cell carcinoma refractory to other therapies or even as a concomitant treatment with newer immunotherapies. The type of healing of the surgical wound could not be associated with a higher rate of response or survival.

Level of evidence: III.

Keywords: Bleomycin; Electrochemotherapy; Head and neck cancer; Healing response; Malignant melanoma; Palliative treatment.