Ian Connellan
During spaceflight, astronauts experience similar physical stress as cancer patients undergoing treatments such as chemotherapy, immunotherapy, and targeted therapy.
NASA astronaut Sunita Williams performs a cardiopulmonary exercise test to assess cardiorespiratory fitness during her time on the International Space Station.
This has led researchers to suggest that by mimicking a NASA astronaut’s schedule of exercising before, during and after a mission, cancer patients could reduce the long-term impact their treatments often have on their bodies.
“It was surprising when we looked at similarities between astronauts during spaceflight and cancer patients during treatment,” says Jessica Scott, an exercise physiology researcher at the Memorial Sloan Kettering Cancer Center in New York and lead author of a paper in the journal Cell.
“Both have a decrease in muscle mass, and they have bone demineralisation and changes in heart function.”
Scott says the similarities extend to brain function: “Astronauts may get something called space fog, where they have trouble focusing or get a little forgetful. That’s very similar to what some cancer patients experience, which is called chemo brain.”
Despite similar symptoms, astronauts and cancer patients often receive very different advice on how to take care of their bodies.
Astronauts are required to exercise before their missions while physicians monitor their cardiorespiratory fitness and other systems to develop a baseline level. Astronauts also exercise during their missions, utilising special equipment made for working out in space.
Upon return to Earth, astronauts’ cardiorespiratory fitness and other systems are monitored by physicians until they return to their pre-mission baseline levels.
Scott says it’s a complete reverse for cancer patients, who are often advised to rest in preparation for and during treatment, and may have to get their doctor’s permission to exercise.
But she and her team– drawn from other medical and cancer centres and NASA’s Johnson Space Center – suggest that basic exercise such as walking on a treadmill could benefit cancer patients in the long term.
Like astronauts preparing for spaceflight, cancer patients could be monitored using similar tests, such as those for cardiorespiratory fitness, to develop their own baseline levels before receiving treatment.
Exercising during and after treatment could then potentially reduce the negative side effects of treatments.
During the 1960s, only 50% of cancer patients survived five years beyond diagnosis, and the immediate concern for medical specialist involved reducing the size and spread of tumours.
At the same time NASA, on the other hand, could focus on developing ways to keep their astronauts healthy.
Today, NASA has technologies that can keep astronauts safely in space for up to 11 months, but for the 90% of patients who now survive early-stage cancer, there have not been similar efforts to counteract the stress their body undergoes during treatment.
“That’s why it’s very timely that we start thinking about how to utilise NASA’s tactics to manage some of these long-term side effects of cancer treatments,” says 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.”
Currently, Scott’s team is examining whether exercise can offset the side effects of therapy in cancer patients.
By providing patients with in-home treadmills and video call software, the patients can participate in the study from the comfort of their home while following the astronaut practice of exercising before, during, and after a mission.
Scott says it’s “very promising” that the NASA exercise framework could be applied to help the many people diagnosed each year with cancer – one million in the US – and the much greater number of cancer survivors.
But she adds that “we really need to do a lot more research and a lot more work”.