Hyperbaric oxygen therapy (HBOT) is widely used to support tissue healing, especially following radiation treatment for cancer. However, some concerns have been raised about whether increased oxygen levels might stimulate the growth of residual tumor cells. This study examined the effects of hyperbaric oxygen exposure on head and neck tumor growth, oxygenation, and vasculature to assess whether HBOT poses any oncologic risks.
Study Overview
Researchers analyzed two human squamous cell carcinoma xenografts—SQ20B and Detroit 562—implanted in experimental models. Tumors were exposed to a regimen of single-dose radiation therapy followed by HBOT five times per week. Each session involved breathing 100% oxygen at 2.4 atmospheres absolute (ATA) for 90 minutes.
The study evaluated:
- Tumor growth rates in both irradiated and unirradiated models
- Oxygenation changes within tumor tissues
- Vascular characteristics, including expression of vascular endothelial growth factor (VEGF) and microvascular density
Key Findings
- No Tumor Growth Acceleration: HBOT did not promote growth in either irradiated or non-irradiated tumors.
- Improved Oxygenation: Tumor oxygen levels increased during HBOT treatment, indicating temporary reduction in hypoxia.
- No Angiogenic Stimulation: Immunohistochemical analysis found no rise in VEGF expression or new blood vessel formation.
- No Persistent Changes: After treatment ended, tumors showed no lasting alterations in microenvironment or growth dynamics.
Research Interpretation
The results demonstrate that HBOT can safely improve tissue oxygenation without enhancing tumor growth or vascularization in head and neck cancer models. These findings are consistent with other studies suggesting that while HBOT alters oxygen dynamics, it does not appear to promote cancer cell proliferation or progression.
Scientific Insight
For clinicians and oncology researchers, this study offers reassurance regarding HBOT’s safety in post-radiation care for head and neck cancer patients. The therapy’s ability to enhance oxygen availability—without inducing tumor growth or angiogenesis—supports its continued use as an adjunctive treatment for radiation-related tissue injury.
Check out the PubMed article here: https://pubmed.ncbi.nlm.nih.gov/15818558/
