Hyperbaric oxygen therapy increases the effect of 5-fluorouracil chemotherapy on experimental colorectal cancer in mice.

Tumor hypoxia may compromise the results of chemotherapy for treating colorectal cancer because it stimulates angiogenesis and the release of tumor growth factors. Hyperbaric oxygen (HBO) supplementation may potentiate the effects of chemotherapy in such cases. This study aimed to assess the effect of HBO therapy combined with chemotherapy on the treatment of colorectal cancer in mice. C57BL6 mice were submitted to the intrarectal instillation of N-methyl-N-nitrosoguanidine (MNNG) and treated with 5-fluorouracil (5FU) and/or HBO therapy. The MNNG group presented the highest dysplastic crypt rate. The 5FU + HBO group presented the highest rate of apoptotic cells per dysplastic crypt. The 5FU group presented the highest expression of hypoxia-inducible factor-1 alpha and CD44. HBO therapy increased the effect of 5FU on the treatment of the experimental colorectal neoplasia in mice.