How can HBOT help fight cancer?
Hyperbaric oxygenation treatment (HBOT) is an effective treatment against different types of cancer, such as: melanoma, leukemia, breast cancer, hemangio-, fibro- and osteosarcoma.
Research has shown that a combination of HBOT with chemotherapy, radiotherapy or ketogenic diet can reduce more tumor mass than any of these treatments on their own. In this post, we will focus on tumor hypoxia and malignant gliomas (brain cancer).
Hypoxia is a state of reduced oxygen availability or decreased oxygen partial pressure that restricts or even abolishes cell functions. It is considered to be one of the pivotal factors for regular treatments like chemotherapy and radiotherapy to fail.
Neoplasia, the growth of tumors, in combination with dysregulated and faulty angiogenesis results in a condition, in which the deeper located tumor cells are not sufficiently supplied with oxygen.
While hypoxia is deadly toxic to regular cells, neoplastic cells have the ability to create defense mechanisms to survive while being oxygen-deprived.
Therefore, a high level of hypoxia slims the patient’s chances of survival and responses to treatment. Poor vascularization and insufficient perfusion in the tumor mass limit the effectiveness of cytostatic drugs.
Glioma is the most common primary brain tumors, they derive from astroglial cells. Glioblastoma, abbreviated as GBM, the most aggressive cancer that begins within the brain. It is characterized for its aggressive biology and infiltrative growth. Standard treatments are usually surgical intervention, radio-, and chemotherapy.
Median survival after diagnosis is around 12 months and less than 15% of patients live beyond two years despite advancements in treatments.
It is thought that tumor hypoxia is one of the main reasons for treatment failures. The administration of higher doses of cytostatic is not an option, due to their toxic side effects on normal, healthy cells.
What is the hyperbaric treatment?
Hyperbaric treatment, common abbreviations are HBOT and HBO, is the process of breathing 100% oxygen while located in a pressurized enclosure.
The outside pressure on the body, in combination with breathing the pure oxygen, can carry oxygen in the blood plasma up to 400% further than normal conditions.
How does it work?
The administration of HBOT provides a lot of clinical benefits in the treatment of tumors. It can be highly advantageous by providing more oxygen molecules and by doing so increase the chemotherapy-generated oxidative stress. In addition, hyperbaric oxygenation overcomes tissue hypoxia and promotes the creation of new blood vessels to transport drug molecules, making neoplastic cells more receptive to chemotherapeutic treatments.
While HBOT on its own is not unconducive to further cancer growth, it might reduce the main tumor mass. It reduces tumor hypoxia by raising the oxygen concentration in the blood plasma.
Another advantage of hyperbaric medicine is that it reduces the collagen content and by doing so it increases the penetration of chemotherapy drugs into the tumor.
(Image based on study by Xian Wu and Yanhong Zhu)
In one in vivo study performed on rats, Brizel et al. had implanted mammary adenocarcinoma (Mammary tumor in layman’s terms). The animals got divided into five groups and positive results were noticed on the groups that were treated with high-pressure gasses, while there was no significant improvement for the groups that underwent treatment using normobaric gasses.
In another study conducted by Thews and Vaupel to test the influences of normo- and hyperbaric hyper-oxygenation, it was found that in standard conditions at 1 atm (equal to sea level) hyperoxia only slightly improved tumor oxygenation compared with normal air. On pressure of 2 atm however, the measured median partial pressure of oxygen (pO2) was five times higher.
After hyperbaric oxygen administration, the spatial pO2 distribution profiles indicated an almost absolute elimination of hypoxic regions, including in large tumors.
Not that much research has been published regarding the use of HBOT in patients with a brain tumor, but Kohshi et al. have focused on the therapeutic effects of hyperbaric medicine on brain tumors and tissue injured by radiation. It is well documented that in brain tumors, just as other solid tumors, oxygen transportation is seriously limited and that local hypoxic regions develop.
A positive impact of HBOT was recorded on the oxygenation of both the brain tissue as well as in the glioblastoma tissue. The oxygen level can rise by as much as 115% upon HBOT exposure.
Beppu et al. measured that hyperbaric oxygenation caused an elevation of pO2 levels in tissue closely surrounding the tumor and inside the tumor, with pO2 levels remained up to 3 times higher than normal for 15 minutes after decompression.
Angiogenesis is known to be a factor to spread cancer (metastasis). As hyperbaric medicine promotes cellular and vascular proliferation in healthy tissue it was assumed to also promote angiogenesis in cancers. Multiple studies, however, have shown that hyperbaric oxygenation has an anti-angiogenic effect.
Hyperbaric oxygenation in combination with other therapeutic treatments can achieve better results while treating some cancers.
The improved flow of oxygen in the body as a result of hyperbaric sessions can not only reduce the tumor cell growth, it will also improve the effectiveness of the treatment used in conjunction, resulting in better chances of survival for the subject.