Hyperbaric oxygen is sometimes used in the course of treatment in head and neck cancer patient. This study was undertaken to investigate the effect of hyperbaric oxygen on oral cavity carcinogenesis in an animal model. Dimethylbenzanthracene was applied three times weekly to induce oral squamous cell cancers. The group that received simultaneous hyperbaric oxygen had fewer tumors, but the tumors were larger than the dimethylbenzanthracene-only group. We concluded that hyperbaric oxygen has a tumor-suppressive effect during the induction phase of oral carcinoma and appears to have a stimulatory effect during the proliferative phase of carcinoma in this animal model.

McMillan, Calhoun, Mader, Stiernberg, Rajaraman, , , , (1989). The effect of hyperbaric oxygen therapy of oral mucosal carcinoma. The Laryngoscope, 1989 Mar;99(3):241-4. https://www.ncbi.nlm.nih.gov/pubmed/2493118