Hyperbaric oxygen pretreatment in autologous HSCT patients shows trends toward improved survival and reduced organ damage.

This retrospective review evaluated the impact of hyperbaric oxygen (HBO) pretreatment in patients undergoing autologous hematopoietic stem cell transplantation (aHSCT). The study compared a cohort of 19 patients receiving HBO against a historical control group of 225 patients. Primary outcomes included overall survival, while secondary outcomes assessed relapse-free survival, non-relapse mortality, secondary malignancies, and organ damage including cardiac, renal, and autoimmune complications.

At the primary outcome level, overall survival was not reached in the HBO cohort compared to 9 years in the historical control cohort (p = 0.59). Relapse-free survival was 4.2 years for the HBO group versus 3.7 years for controls (p = 0.34). However, the cumulative incidence of non-relapse mortality showed a lower trend in the HBO cohort (p = 0.057).

Regarding secondary outcomes, the incidence of secondary malignancies excluding non-melanoma skin cancers was reduced in the HBO cohort (5.26% vs. 22.07%, p = 0.074). Organ damage rates were lower in the HBO group (47.4% vs. 61.3%, p = 0.12). Specifically, cardiac damage was significantly reduced (5.3% vs. 23.9%, p = 0.046), and renal damage was significantly reduced (15.8% vs. 42.8%, p = 0.016). Autoimmune disease was less observed in the HBO cohort (0.0% vs. 7.69%, p = 0.14).

Safety and tolerability data were not reported in the provided evidence. The study design is limited by its retrospective nature and the use of a historical control cohort, which may introduce selection bias. The small sample size of the HBO cohort (n=19) limits the generalizability of the results. These findings should be interpreted as hypothesis-generating rather than definitive proof of efficacy.