Prostate cancer is the most common cancer among Dutch men, with good survival rates. If the disease is confined to the prostate, the tumour can be surgically removed, but this is not possible in (locally) advanced tumours. In those cases, hormone therapy (androgen deprivation therapy) inhibits tumour growth by lowering testosterone levels. Although that treatment works well, it also causes side effects, such as fat gain and muscle loss. In the long term, that in turn can have adverse effects. For instance, people may have more difficulty with their daily activities and it can potentially increase the risk of other diseases, such as diabetes and cardiovascular problems.

Strength training is the most effective method for increasing muscle mass and strength, but since testosterone also plays a role in maintaining muscle mass and muscle changes after training, the question was whether strength training also works for people undergoing hormone therapy.

Strength training

Sixty prostate cancer patients treated with hormone therapy did muscle-strengthening exercises twice a week for 20 weeks. While a control group of 36 patients, gained fat and lost muscle mass in that short time, the group that trained appeared to gain less in fat mass while gaining muscle mass. 'We would already have been happy to see muscle preservation, but the study shows that patients can even build muscle mass,' Houben said. Muscle biopsies confirmed these results at the muscle cell level, which also translated into more muscle strength and less loss of endurance than in the non-training group.

Training not only offered physical benefits, people also found it fun to do. 'It gives people a chance to do something themselves in their disease process,' Houben says. 'But we also saw that peer contact was important. Patients trained together in small groups in which they motivated each other, but also found the space to talk about, for example, hot flushes or breast formation; side effects of the therapy that you don't just share with others.'

Sustain

Because hormone therapy is often continued for two years or more, Houben investigated whether patients could independently maintain this improvement in health after the supervised programme ended. 'Eight in 10 participants continue some form of strength training on their own, so people are motivated to continue. We saw that the effect on fat mass was maintained after year, but the increase in muscle mass was lost, as was some of the muscle strength.'

Because it proves difficult for patients to maintain long-term health gains on their own, Houben would prefer to offer people supervised strength training throughout the treatment period. 'We have now shown that it is possible to improve physical health patients undergoing hormone treatment. We can build on that, for example by working on tailored training depending on the activities that are important for the patient to be able to continue doing.'

PhD defence Lisanne H.P. Houben, 11 January 2024 10.00 hrs.

“Exercise training in prostate cancer patients on androgen deprivation therapy’

Supervisor: Prof. dr. L.J.C. van Loon

Co- Supervisors: Dr. S. Beijer Dr. M. Beele