Cancer treatment can be physically demanding. Surgery, chemotherapy, and radiation therapy can help manage cancer, but they may also affect healthy tissues and lead to complications during or after treatment.
One therapy that is increasingly discussed in this context is Hyperbaric Oxygen Therapy (HBOT). HBOT involves breathing high-concentration oxygen inside a pressurized chamber. By increasing oxygen availability in certain damaged or oxygen-deprived tissues, HBOT may support the body’s natural healing processes.
However, it is important to understand one key point: HBOT should not be considered a replacement for cancer treatment. Current evidence is much stronger for using HBOT to manage certain complications of radiation therapy, particularly delayed radiation injuries and tissue damage. The role of HBOT directly in treating cancer itself continues to be studied. The Undersea & Hyperbaric Medical Society identifies delayed radiation injury as an established application of hyperbaric oxygen therapy.
Can HBOT Treat Cancer?
The relationship between oxygen and cancer is complex. Cancer cells can behave differently from healthy cells, and tumor oxygen levels may vary depending on the type and stage of cancer.
Early laboratory and animal studies have explored whether increasing oxygen levels can influence tumor biology or make certain cancer treatments more effective. Some studies have reported encouraging findings, but these results should not be interpreted as proof that HBOT can eliminate or cure cancer in humans.
For this reason, HBOT is generally best viewed as a supportive or adjunctive therapy in carefully selected patients, rather than as a standalone cancer treatment.
If you are undergoing chemotherapy, radiation therapy, or another cancer treatment, HBOT should only be considered after discussion with your oncologist and a qualified hyperbaric medicine specialist.
HBOT and Different Types of Cancer
Research has explored the potential role of HBOT in several cancer-related settings, including brain tumors, head and neck cancers, breast cancer, and other malignancies.
Some experimental studies have investigated whether increasing tissue oxygenation could improve the response to radiation or chemotherapy. However, much of this evidence comes from laboratory, animal, retrospective, or small clinical studies.
Therefore, claims that HBOT directly reduces tumor size, prevents cancer recurrence, or improves cancer survival should be made cautiously unless supported by strong clinical evidence.
Importantly, recent evidence also provides reassurance regarding the safety of HBOT in cancer survivors. A 2025 study involving patients with oral cancer who had undergone surgery and radiation found that HBOT used for osteoradionecrosis did not significantly affect second-primary cancer development, disease-specific mortality, or overall mortality.
Where HBOT Has a Well-Established Role: Cancer Treatment Complications
One of the most important applications of HBOT in oncology is the management of delayed radiation injuries.
Radiation therapy is designed to damage cancer cells, but surrounding healthy tissue can also be affected. In some patients, radiation-related tissue damage develops months or even years after treatment.
These complications may include:
- Radiation cystitis
- Radiation proctitis
- Soft-tissue radiation injury
- Osteoradionecrosis
- Radiation-related wounds
- Radiation necrosis in selected tissues
The UHMS notes that delayed radiation injuries are among the most frequently treated indications for HBOT and that treatment often requires a multidisciplinary approach.
How HBOT May Help Radiation-Damaged Tissue
Radiation can cause changes to small blood vessels and reduce the ability of affected tissues to repair themselves.
HBOT exposes the patient to high concentrations of oxygen under increased atmospheric pressure. This can substantially increase oxygen availability in tissues and may support processes involved in healing, including angiogenesis-the formation of new blood vessels.
Research into delayed radiation injury suggests that the benefits of HBOT may involve improved tissue oxygenation, stimulation of new blood vessel formation, reduction of fibrosis, and other biological effects associated with tissue repair.
The goal is not to treat the cancer directly. Instead, the objective is to help damaged healthy tissue recover and improve symptoms or healing where HBOT is medically appropriate.
Radiation Necrosis and HBOT
Radiation necrosis is a serious complication that can occur when previously irradiated healthy tissue becomes damaged and loses its ability to heal normally.
The location of radiation injury can vary depending on the area that received radiation.
Head and Neck
Patients may develop radiation-related damage involving the jaw, mouth, throat, or surrounding soft tissues. Osteoradionecrosis of the jaw is one of the most established applications of HBOT.
Pelvic and Abdominal Areas
Radiation treatment for cancers in the pelvis or abdomen can sometimes lead to delayed injury involving the bladder, bowel, or rectum.
For example, radiation cystitis can cause urinary symptoms and bleeding, while radiation proctitis can affect the rectum and cause discomfort or bleeding.
Research has reported encouraging outcomes when HBOT is used as part of treatment for radiation cystitis. A 2024 analysis of Medicare data involving more than 3,300 patients reported reductions in urinary bleeding and other healthcare interventions among patients receiving HBOT.
Breast and Chest Wall
Radiation-related soft-tissue injury can also affect the chest wall following breast cancer treatment. Symptoms may include pain, fibrosis, restricted movement, skin changes, or delayed wound healing.
HBOT may be considered in selected cases where radiation injury has resulted in significant tissue damage.
HBOT and Brain Radiation Necrosis
Radiation necrosis can also affect the brain after radiation treatment for certain brain tumors or metastatic cancers.
Symptoms can vary depending on the affected area and may include headaches, neurological changes, cognitive difficulties, seizures, or other problems.
HBOT has been investigated as a potential supportive treatment for radiation-related brain injury. However, brain radiation necrosis requires careful diagnosis because its symptoms and imaging findings can sometimes resemble recurrent or progressive cancer.
Patients should therefore be evaluated by their oncology and specialist medical teams before HBOT is considered.
Can HBOT Help With Cancer-Related Fatigue?
Cancer and its treatments can cause significant fatigue. It is understandable that patients may look for therapies that could improve energy levels and quality of life.
However, evidence supporting HBOT specifically for general cancer-related fatigue remains limited. HBOT should not be promoted as a proven treatment for cancer fatigue without appropriate clinical evidence.
If fatigue is severe or persistent, the underlying causes-including anemia, sleep problems, nutritional issues, medications, infection, or the cancer itself—should first be evaluated by the treating medical team.
What About Anemia?
Anemia is common in some cancer patients and may occur because of the disease, chemotherapy, blood loss, nutritional deficiencies, or other factors.
HBOT temporarily increases the amount of oxygen dissolved in blood plasma, but it is not a routine treatment for cancer-related anemia.
Anemia should be evaluated and treated according to its underlying cause. Depending on the situation, treatment may involve nutritional supplementation, medication, blood transfusion, or other medical interventions.
Mucositis and Esophagitis
Chemotherapy and radiation can sometimes cause inflammation and damage to tissues lining the mouth, throat, esophagus, or digestive tract.
These complications can make eating, drinking, and swallowing difficult.
HBOT has been investigated for several types of radiation-related tissue injury, but its use for mucositis or esophagitis should be determined on an individual basis. It should not replace standard supportive care prescribed by the oncology team.
What About “Chemo Brain”?
Many cancer patients report difficulties with memory, concentration, attention, or mental clarity during or after treatment. This is commonly referred to as cancer-related cognitive impairment or “chemo brain.”
Although individual reports and early research have explored whether HBOT may influence cognitive symptoms, there is not enough evidence to describe HBOT as an established treatment for chemo brain.
Patients experiencing persistent cognitive difficulties should discuss their symptoms with their oncologist. Other factors, such as sleep, medications, anxiety, depression, anemia, hormonal changes, and fatigue, may also contribute.
Is HBOT Safe for Cancer Patients?
The answer depends on the individual patient’s medical condition, cancer history, current treatment, and reason for undergoing HBOT.
Modern evidence does not support the idea that HBOT automatically causes cancer to grow or that a history of cancer automatically prevents a patient from receiving HBOT. In fact, current hyperbaric literature continues to examine the safety of HBOT in patients with a history of cancer.
At the same time, HBOT is not appropriate for every patient. The decision should consider:
- Current cancer status
- Previous cancer treatments
- Type and location of radiation injury
- Current medications
- Other medical conditions
- The specific reason HBOT is being recommended
Patients receiving active chemotherapy should receive individualized medical advice because evidence regarding concurrent chemotherapy and HBOT varies depending on the drug and clinical situation. UHMS notes that published evidence on concurrent chemotherapy and HBOT remains limited for some scenarios.
HBOT Should Complement, Not Replace, Cancer Care
The most important takeaway is that HBOT should not replace surgery, chemotherapy, radiation therapy, immunotherapy, targeted therapy, or other evidence-based cancer treatments.
Instead, in appropriate cases, it can serve as an adjunctive therapy-particularly when the patient develops delayed radiation-related tissue damage.
The purpose of HBOT in these situations is to improve the healing environment of damaged tissue, support recovery, and potentially improve quality of life.
Frequently Asked Questions About HBOT and Cancer
1. Can HBOT cure cancer?
No. HBOT should not be promoted as a cure for cancer. Research is ongoing into its potential effects in cancer-related settings, but established cancer treatments remain the standard approach for treating malignancies.
2. Can cancer patients undergo HBOT?
Some cancer patients and cancer survivors may be candidates for HBOT, particularly when they develop certain radiation-related complications. The decision should be made by a qualified hyperbaric physician in consultation with the patient’s oncology team.
3. Is HBOT used for radiation necrosis?
Yes. HBOT is an established application for selected delayed radiation injuries, including certain forms of soft-tissue and bone necrosis.
4. Can HBOT be used after radiation therapy?
Yes, HBOT may be considered for certain delayed radiation injuries after radiation therapy. The appropriate timing and treatment plan depend on the patient’s condition and should be determined by a specialist.
5. Does HBOT make cancer cells grow faster?
Current evidence does not support the simple claim that HBOT causes cancer to grow faster. Research continues to investigate the complex relationship between oxygen and cancer biology. A 2025 observational study in patients treated for oral cancer found no significant adverse effect of HBOT on second-primary cancer development or survival outcomes.
6. Can HBOT be taken along with chemotherapy?
Sometimes, but this requires individual medical assessment. The safety of combining HBOT with chemotherapy depends on the specific medication, treatment schedule, and reason for HBOT. Patients should never make this decision without consulting their treating doctors.
7. Can HBOT treat radiation cystitis?
HBOT can be used as an adjunctive treatment for selected cases of delayed radiation cystitis. Clinical research has reported improvements in bleeding and reductions in some subsequent interventions.
8. How does HBOT help radiation-damaged tissue?
HBOT increases oxygen availability in tissues and may support healing processes such as angiogenesis and tissue repair. Radiation-damaged tissues can have impaired blood supply and reduced healing capacity, making improved oxygenation potentially beneficial.
Conclusion
Cancer care does not always end when the primary treatment is completed. Some patients experience long-term effects from radiation or other cancer therapies that can significantly affect their comfort, mobility, and quality of life.
Hyperbaric Oxygen Therapy has an important and well-established role in managing selected delayed radiation injuries, where increased tissue oxygenation may support healing and recovery. Current evidence also continues to investigate its safety and potential applications in cancer patients.
However, HBOT should be presented accurately: it is not a standalone cure for cancer and should not replace conventional cancer treatment. Its greatest established value in oncology is as a supportive treatment for appropriate radiation-related complications.
If you are considering HBOT after cancer treatment, speak with your oncologist and a qualified hyperbaric medicine specialist. A proper medical evaluation can determine whether HBOT is appropriate for your specific condition and treatment history.
