Would you believe me if I told you that a treatment for cancer used in ancient Egypt is proving to be effective in 21st century America? That’s right—the first known mention of therapeutic hyperthermia, which involves using hot water to heat a tumor and the surrounding area, appeared in a 5,000-year-old papyrus! Today, doctors at some cancer centers are using noninvasive mild-heat hyperthermia to boost the effectiveness of other cancer therapies, especially radiation, without increasing the dosage and subsequent risk for unwanted side effects.

How it works: I spoke with radiation oncologist Jennifer Yu, MD, PhD, director of the Center For Hyperthermia at the Cleveland Clinic and a member of the governing council of the Society for Thermal Medicine. She explained that mild-heat hyperthermia combats cancer several ways. For instance, it…

• Disables certain enzymes, impairing the cancer cells’ ability to repair the DNA damage caused by radiation.

• Improves blood flow to the area where the tumor is, bringing more oxygen to the tissues, which in turn increases the effectiveness of radiation.

• Damages proteins and structures within cancer cells, causing tumors to shrink—while doing minimal damage to normal tissues.

• Kills cancer stem cells that often are resistant to radiation.

• May enhance the effects of certain anticancer drugs.

• Supports the immune system, increasing the body’s ability to fight off the cancer.

What happens during treatment: In Dr. Yu’s practice, hyperthermia is added to a course of radiation. For instance, suppose a patient is scheduled to undergo five radiation sessions per week for four weeks. If she is receiving hyperthermia, she also would get two sessions of the mild-temperature hyperthermia therapy, administered immediately before the radiation (the other three days per week, radiation would be administered alone).

Typically hyperthermia is applied with hot-water bags that are carefully positioned and precisely heated with an external microwave unit and temperature monitors. Temperatures are maintained at slightly above “fever range,” or around 110°F. The patient lies in a darkened room for an hour during the hyperthermia treatment. “It feels like a heating pad. Many patients take a nap during the treatment,” Dr. Yu said. Once the hyperthermia session is over, the patient immediately moves on to the radiation.

Risks and side effects are minor. In about 10% of cases, small blisters develop. This is most common on the skin near a cancer surgery site because blood flow in scarred areas is reduced, so heat is not carried away by the circulating blood as efficiently as it normally would be. This is usually a minor discomfort, though. “Spilling coffee on yourself would probably hurt more, and these blisters usually heal on their own. They’re not so severe that we have to stop treatment,” Dr. Yu said.

Types of cancer treated: Mild-heat hyperthermia is most often used to treat cancers that occur near the surface of the body, such as breast cancer, melanoma, and head and neck cancers. It also is increasingly being used for other types of cancer as well, including cancers of the cervix, prostate, rectum, pancreas, brain, bladder and liver.

Though hyperthermia can help patients who are facing their first bouts with cancer, research suggests that it is especially beneficial for people with recurring cancer where radiation didn’t help as much as doctors had hoped initially, Dr. Yu said. For instance, according to one study from Duke University Medical Center that looked at patients with recurrent breast cancer, hyperthermia combined with radiation successfully eradicated tumors in 65% of cases, versus just 42% for radiation alone. For patients whose cancer has metastasized, whole-body hyperthermia may be done using warm-water immersion.

Where to get treatment: Most insurance companies cover hyperthermia therapy. However, the treatment requires a large team of specialized practitioners—at the Cleveland Clinic, for example, it includes a physician, medical physicist, and nurses and therapists specially trained in hyperthermia and repeat radiation. When I asked Dr. Yu why this safe and effective treatment isn’t more widely available, she said, “Many places do not have the personnel or infrastructure to run these types of facilities, and few young physicians are trained in how to deliver hyperthermia.” If you are interested in having a consultation with a doctor who provides this treatment, enlist your oncologist’s aid in finding a practitioner.

Though cancer is a very complex disease, it’s heartening to know that something as simple as hot water could help you treat it.

For lots more info on complementary care: Read “Complementary Cancer Therapies: A Guide for Patients and Survivors