Hyperbaric Oxygen Treatment after Surgery and Radiation for Oral Cancers Does not Increase the Likelihood of a Second Primary Development, nor Reduce Disease Specific or Overall Survival

ABSTRACT Hsieh CH, Wen YW, Liao CT, Lee SR. Hyperbaric Oxygen Treatment after Surgery and Radiation for Oral Cancers Does not Increase the Likelihood of a Second Primary Development, nor Reduce Disease Specific or Overall Survival. Undersea Hyperb Med. 2025 Third Quarter; 52(3):271-278. Objective: This study aims to analyze whether receiving Hyperbaric oxygen (HBO2) therapy affects oral cancer prognosis using real-world data from the National Health Insurance Research Database (NHIRD) in Taiwan. Method: This study is a retrospective cohort study. Cancer registration files, the NHIRD, and death statistics files from 2011 to 2019 were used for data extraction. We identified 6,297 oral cancer patients, all of whom underwent tumor resection surgery and radiation therapy. Among them, 254 patients received HBO2 therapy for osteoradionecrosis. We then divided them into two groups for comparison based on whether they received HBO2 therapy or not. First, propensity score matching was used to eliminate basic characteristic differences between the groups, and then Kaplan-Meier survival analysis was conducted. To eliminate immortal time bias and obtain hazard ratios, a time-dependent Cox proportional hazards model was used for estimation. Result: After undergoing curative tumor resection combined with adjunctive radiation therapy, oral cancer patients were divided into two groups based on whether they received hyperbaric oxygen therapy. The estimation using a time-dependent Cox proportional hazards model showed no statistically significant differences in the three follow-up endpoints of this study: incidence of second primary cancer, disease-specific mortality, and all-cause mortality, in terms of hazard ratios. Conclusion: In Taiwan, whether oral cancer patients receive hyperbaric oxygen therapy after curative tumor resection surgery combined with radiation therapy does not affect the incidence of second primary cancer, disease-specific mortality rate, and all-cause mortality rate. Keywords: cancer registry; carcinogenesis and hyperbaric oxygen; survival after hyperbaric oxygen for oral cancers