Electrochemotherapy in primary and metastatic skin tumors: phase II trial using intralesional bleomycin.

BACKGROUND: Surgery and/or radiotherapy are the elective therapies for most primary skin cancers. Nevertheless, some patients develop recurrences, and chemotherapy has resulted in poor complete responses. Permeabilization of the cell membrane by electric pulses allows bleomycin to enter into the cell, increasing possibility of cytotoxicity. METHODS: From November 1998 through November 1999, 15 patients with 38 skin lesions participated in a phase II prospective clinical trial, using intralesional bleomycin plus electric pulses delivered 10 min after bleomycin injection, which lasted 100 microsec each at field strength of 1,300 V/cm and a frequency of 1 Hz. There were basal cell carcinomas (BCC) (nine lesions), in-transit metastasis of melanoma (MM) (two patients/13 nodules), squamous cell carcinomas (SCC) of the upper aerodigestive tract metastatic to the skin (two patients/two nodules), and skin metastases from breast cancer (two patients/14 nodules). Mean follow-up was 8.6 months. RESULTS: Overall objective responses were 98%, with complete responses achieved in 49%, partial responses in 49%, and no responses in 2%. No complications were documented related to the treatment and tolerance was adequate. CONCLUSIONS: Electrochemotherapy (ECT) is a new cancer modality of treatment that is effective in a variety of skin cancers. This treatment represents an excellent alternative to standard surgery or radiotherapy, with an outpatient-based treatment applied in one to three sessions. The major impact was obtained in BBC, but ECT is a useful palliative therapy in melanoma, breast cancer, or SCC. More experience and longer follow-up are required to determine long-term results.