The present report is the sixth in a series of combination therapy trials in oral carcinoma in South India conducted since 1960. In the fifth trial a combination of bleomycin (BLM) and irradiation was compared with irradiation alone. The results gained and the subsequent experience in an unselected series demonstrated in buccal mucosal squamous cell carcinomas a highly superior effect with the irradiation-BLM combination, but still revealed a failure rate around 30 per cent. The present clinical trial–irradiation + BLM was compared with irradiation + BLM + hyperbaric oxygen (HbO) and irradiation + placebo + HbO–was undertaken in an attempt to eliminate or at least reduce these failures. The results were unexpectedly disappointing in that the irradiation combined with BLM + HbO proved to be inferior to irradiation + BLM. An attempt has been made to elucidate the possible reasons for this surprising outcome.

Shanta, Krishnamurthi, Sharma, , , , , , (1983). Irradiation, bleomycin and hyperbaric oxygen in the treatment of oral carcinoma. Acta radiologica. Oncology, 1983 ;22(1):13-6. https://www.ncbi.nlm.nih.gov/pubmed/6190357