Bleomycin-sensitivity test: application for human squamous cell carcinoma

Bleomycin (BLM)-inactivating enzyme activity, which is probably a parameter for the efficacy of this antibiotic in cancer therapy, was determined in biopsies from human carcinomas in the head and neck region. Twenty-three cases were studied. It was found that highly differentiated as well as moderately differentiated squamous cell carcinomas had low extractable activities of this enzyme, comparably to those found in normal skin tissue. Slightly differentiated as well as undifferentiated carcinomas (only one case) had increased enzyme activity. Parallel experiments estimating the total extractable thiol content in the biopsies gave no obvious correlation. The results are discussed in the light of the reported BLM efficacy in the treatment of differently differentiated squamous cell carcinomas.