Startling similarities in the diminished physical state of astronauts aboard the International Space Station (ISS) and the physical stress cancer patients experience post chemotherapy has led to a proposal that the training regimen used to keep astronauts fit and healthy be applied to cancer patients to help them recover after treatment.

Long-term spaceflight has serious deleterious effects on the human body and causes multiple health problems. One of the most significant of these problems is loss of bone and muscle mass, which cancer patients also experience but for different reasons. For astronauts, these spaceflight problems can increase their risk of injury, reduce their aerobic capacity and slow down their cardiovascular system.

Another significant problem faced by astronauts is their muscles quickly weaken and atrophy or waste away in the microgravity of space. Exposure to long-term reduced gravity reduces muscle mass and strength, especially in the legs.

Astronauts deployed for six months or more on the ISS can also experience blood volume loss, weakened immune systems and cardiovascular deconditioning. This is because floating takes little effort and the heart doesn't have to work as hard to pump blood, according to NASA's Human Research Program.

The proposal to develop an astronaut training system for cancer patients was published in a commentary written by researchers from Memorial Sloan Kettering Cancer Center and NASA on Thursday in the journal Cell. The project is supported by the National Cancer Institute.

"It was surprising when we looked at similarities between astronauts during spaceflight and cancer patients during treatment," Jessica Scott, senior author and an exercise physiology researcher at the Memorial Sloan Kettering Cancer Center's Exercise Oncology Service, said. "Both have a decrease in muscle mass, and they have bone demineralization and changes in heart function."

Scott also said astronauts may come down with something called "space fog," where they have trouble focusing or get a little forgetful. She added this condition is very similar to what some cancer patients experience, which is called "chemo brain."

A new series of "countermeasures" are needed to mitigate the stresses and toxicity early-stage cancer patients face during treatment. Managing toxicity is currently the job of the drugs that target the function of individual organs. Drugs, however, don't help patients recover to their normal levels before being diagnosed.

"That's why it's very timely that we start thinking about how to utilize NASA's tactics to manage some of these long-term side effects of cancer treatments," noted Scott. "Many patients aren't dying from their cancer, but they're now at risk of dying from these side effects. Using NASA's exercise plan could help with this."

Researchers suggested even walking on a treadmill might help cancer patients. Tests are also needed to monitor their fitness over time to develop a baseline level and reduce the risk of heart problems that might occur as side effects from treatment.

Scott's team at Sloan Kettering is currently investigating how exercise may offset these treatment side effects. They've provided patients with treadmills in their homes and video call capability to help them exercise before, during and after treatment.

International Space Station
The International Space Station is cleaner than your bathroom. Pixabay Public Domain

"A tremendous opportunity exists to leverage 60 years of space medicine to establish a program of research that optimizes preparation for, tolerability of, and recovery from a cancer diagnosis and treatment," the researchers wrote.

Researchers said in order for the countermeasures program to be viable, it will need to be cost-effective and provide the desired outcomes and benefits. If it works, it could "change the landscape of cancer care and management."

"We really need to do a lot more research and a lot more work," Scott pointed out. "But it's very promising that this NASA exercise framework could be applied to help the approximately one million individuals that will be diagnosed with cancer in the United States this year, as well as the over 15 million cancer survivors in the United States today."

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