Is Hyperbaric Oxygen Therapy Safe for Cancer Patients?

By Lisa St. John, M.S.
Is Hyperbaric Oxygen Therapy Safe for Cancer Patients?

Research strongly suggests that hyperbaric oxygen therapy does not stimulate tumor growth. Some recent studies in fact suggest that HBOT may actually inhibit tumor growth, especially in combination with specific chemotherapy drugs.

Hyperbaric Oxygen Therapy Treats Numerous Medical Conditions

Hyperbaric oxygen therapy (HBOT) has been widely used to treat various medical conditions, including non-healing wounds and radiation injuries. Some radiation oncologists though have expressed concern about HBOT for patients with malignant cancer cells or tumors. Specifically, they question whether HBOT can lead to further growth of malignant cancer cells or promote the growth of blood vessels (angiogenesis) that can supply blood and oxygen to tumors, which causes them to spread.

Research Shows that HBOT Does Not Stimulate Tumor Growth

That said, research strongly suggests that hyperbarics does not stimulate tumor growth. Some recent studies in fact suggest that hyperbaric oxygen therapy may actually inhibit tumor growth.

It is important to understand that tumor angiogenesis is a complex process that is influenced by many factors. The main issue though is that there are real differences in how angiogenesis works to heal wounds versus how it works on tumors and cancer malignancies.

Let’s take a look at some background about the impact of angiogenesis in cancer patients. Tumors that grow in oxygen deprived (hypoxic) environments are:

  • more prone to spreading (metastases) 
  • more lethal to patients
  • more likely to mutate, which makes them more resistant to treatment

A tumor cell that is hypoxic has a very low blood flow, which means that they can’t receive as much of the chemotherapy drugs that are intended to kill the cells. It turns out that by increasing oxygen in tumor cells, HBOT makes tumors more sensitive to irradiation and chemotherapy drugs. Basically, increased oxygen makes these therapies function better. 

In addition, hyperbaric oxygen helps heal the rest of the body, including the cells surrounding the tumor. Hyperbaric oxygen also causes the body to eliminate cells that are becoming less effective and are dying (senescent cells). HBOT increases the removal of senescent cells by up to 37%, which helps the rest of the body function better.

In essence, there has been no high quality research on cancer growth and angiogenesis in tumors that shows hyperbaric oxygen therapy promoting the growth of malignant cancer cells or metastases. According to current research, a history of malignancy should not be considered a contraindication for hyperbaric oxygen therapy. There has been fear from oncologists. These fears are reasonable because caution keeps us all safe. Fortunately, these fears turn out to be unfounded and HBOT has been shown to be safe for cancer patients.

HBOT Offers Some Anti-tumor Effects

Moreover, some recent studies have shown that HBOT can actually have anti-tumor effects. They also highlight several likely mechanisms that cause these anti-tumor effects. One way hyperbaric oxygen inhibits tumor growth is by increasing oxygen levels within tumor tissues. Tumors tend to have a disorganized and inefficient vascular network. Thus, when HBOT delivers a high oxygen content to tumor cells, it can prove toxic to tumor cells. In medical terms, oxygen under pressure can stimulate reactive oxygen species (ROS), which can induce oxidative stress and DNA damage in tumor cells, leading to their death.

HBOT Can Increase the Effectiveness of Some Chemo Drugs

Hyperbaric oxygen therapy has been found to enhance the effectiveness of radiation therapy and certain chemotherapeutic drugs:

  • Radiation therapy relies on the production of reactive oxygen species to damage tumor DNA. HBOT can amplify this effect by increasing oxygen levels within the tumor. 
  • HBOT has been shown to sensitize tumor cells to some chemotherapeutic agents. These cells are then more susceptible to the drugs' effects, which are to kill tumors. In other words, HBOT helps some chemotherapy drugs to kill tumors. 

Specifically, HBOT can help increase the effectiveness of Doxil. In these Stage 3 trials, HBOT was shown to overcome tumor hypoxia, which improved tumor penetration for DOXIL.

HBOT not only improved Doxil tumor penetration by decreasing the collagen deposition, but also sensitized tumor cells to Doxil. As a result, the combination treatment synergistically inhibited H22 tumor growth, with a tumor inhibition rate of 91.5%. The authors concluded that the combination of HBOT with Doxil showed neither extra side effects nor promotion of tumor metastasis. These findings revealed that the combination of HBOT with Doxil is a safe and effective treatment modality.

HBOT Increases Immune Response

HBOT can also modulate the tumor microenvironment and the immune system in a couple ways:

  • Adding oxygen to tumor tissues can increase the number of immune cells (such as cytotoxic T cells) into the tumor. These cells can help in the recognition and destruction of cancer cells.
  • HBOT has also been shown to reduce the expression of certain proteins involved in tumor invasiveness and metastasis.

Studies are currently underway to look at the combination of HBOT and radiation for glioblastoma.

Our Approach to Treating Patients

As with patients undergoing treatment for any medical condition, it is essential to carefully evaluate each patient's condition and consult with an oncologist. Our goal is to determine the suitability and potential benefits of HBOT as part of an individualized cancer treatment plan. 

We Work Closely with the Patient’s Care Team

Our approach to working with patients, regardless of condition, is to work closely with the patient’s care team, which includes their primary care physician as well as specialists, including Oncologists. Oncologists who currently refer patients to Bay Area Hyperbarics stay updated with the latest research. They also consult with other healthcare professionals to make informed decisions about treatment options for their patients. Getting this right matters.

Thorough Evaluation and Screening Process

Before initiating HBOT, patients undergo a thorough evaluation and screening process to identify any contraindications or potential risks. This assessment helps determine whether a patient is suitable for HBOT and ensures that any underlying conditions or medications are taken into consideration to maximize safety.

Tailored Treatment Plan

In addition, each patient's treatment plan is tailored to their specific medical condition and needs. The duration and frequency of HBOT sessions are determined based on the patient's diagnosis, response to treatment, and overall health status. This personalized approach helps minimize the risks and maximizes the therapeutic benefits.

We Follow All Standard Protocols

Our physicians, nurses and technicians follow specific treatment protocols approved by Medicare, the UHMS (Undersea Hyperbaric Medical Society), and leading peer-reviewed research in the field.



Oxygenation inhibits ovarian tumor growth by downregulating STAT3 and cyclin-D1 expressions. Cancer Biol Ther. 2010 Aug 15;10(4):386-90. Karuppaiyah Selvendiran et al.


Hyperbaric oxygen as a chemotherapy adjuvant in the treatment of osteosarcoma. Once Rep. 2009 Nov;22(5):1045-50. Yasuomi Kawasoe, et al.


Hyperbaric oxygen: does it promote growth or recurrence of malignancy? Undersea Hyperb Med. 2003 Spring;30(1):1-18.


Hyperbaric Oxygen Therapy for Malignancy: A Review. World Journal of Surgery. 2006. World J Surf, 2006, 30: 2112-2131. Justine Daruwalla, et al.


Wiley Online Library, Advanced Science. Wu X, Zhu Y, Huang W, Li J, Zhang B, Li Z, Yang X. Hyperbaric Oxygen Potentiates Doxil Antitumor Efficacy by Promoting Tumor Penetration and Sensitizing Cancer Cells. Adv Sci (Weinh). 2018 Jun 25

Lisa St. John, M.S.
Lisa St. John, M.S.
Clinic Director and Founder

Lisa is our Clinic Director and Founder. She earned her Master’s degree from Harvard University, completed a Fellowship at Stanford University, and has spent the last 30 years working in the healthcare field.

Share this:
Want to learn how HBOT can help your body heal?

Give us a call today to learn more about how HBOT can help keep your body strong during cancer treatment.


Leave us a message and we’ll get back to you as soon as possible.


San Jose/Los Gatos Clinic
14589 South Bascom Avenue,
Los Gatos, CA 95032

PH: 408-356-7438
Mon-Fri: 5:30 am – 8:00 pm
Sat & Sun: 8:00 am – 2:30 pm
BILLING HOURSMon-Fri: 9:00 am – 4:00 pm
NEW PATIENTSMon-Fri: 8:00 am – 2:30 pm

©2024 Bay Area Hyperbarics. All Rights Reserved