A new treatment method may significantly improve the prognosis of men with recurrent prostate cancer. The method can extend their life expectancy without worsening their disease.
The method was developed by US-based Cedars-Sinai, a Los Angeles hospital in the US state of California. The method has recently been clinically tested. The results of these clinical trials are shared by the researchers in New England Journal of Medicine.
Number of diagnoses more than doubled in 30 years
Prostate cancer is affecting more and more patients. They figures from the Integral Cancer Centre of the Netherlands (KNL) show that the number of new patients with prostate cancer per year has more than doubled in 30 years. About 104 per 100,000 men were diagnosed with prostate cancer in 2022. In 2022, over 90% of patients were 60 years or older, while 35% were 75 years or older.
The disease can present itself in different forms. In some cases, it is a slow-growing form of the disease that requires no treatment. Others involve a more aggressive form, which in many cases is treated with surgery or radiotherapy.
Disease may return
Prostate cancer unfortunately returns at a later stage in many cases. "In about a third of these patient, the cancer unfortunately returns within 10 years," said Stephen Freedland, MD, associate director for Training and Education and the Warschaw, Robertson, Law Families Chair in Prostate Cancer at Cedars-Sinai.
Currently, patients with aggressively recurrent prostate cancer receive so-called androgen deprivation therapy (ADT). This is a hormone therapy that aims to stop tumour growth. The growth of prostate cancer cells is largely dependent on testosterone. Which is an androgenic or male hormone, produced mainly in the testes. Hormone therapy stops or blocks the production of testosterone.
The downsides of ADT
ADT has drawbacks, however. Freedland points out two downsides: the therapy does not completely eliminate the presence of testosterone and the method has many side effects. "If you go on ADT, the testosterone level in the blood drops but it is not completely eliminated," Freedland says. "The concern is that the testosterone that remains present may be enough to stimulate tumour growth. In addition, patients do not like the idea of taking hormones."
Two methods were tested in a clinical trial of 1,068 patients with prostate cancer ui 17 countries. A third of the patients received ADT in combination with the drug enzalutamide, which blocks the effects of testosterone. Enzalutamide thus prevents the remaining testosterone from stimulating the growth of cancer cells.
Another third of patients received enzalutamide alone. The drug was used in this case to stop the action of testosterone without lowering the amount of testosterone in the blood. The third and final group of patients received exclusively ADT, which is currently the standard treatment.
Both methods reduce risk
The study shows that a combination of ADT and enzalutamide reduces the risk of metastasis or death by 58% more than using ADT alone. It also shows that deployment of enzalutamide alone lowers the risk of metastasis or death by 37%. In both cases, patients' quality of life is similar to patients receiving ADT alone.
Freedland stresses that the treatment that best suits each patient varies. "Although combined therapy reduces the risk the most, some men may prefer enzalutamide alone. It works well to prevent the spread of cancer or death, with other side effects that may be more acceptable for some men," says the medical director and researcher.
Further information is available in the New England Journal of Medicine, in which the researchers share their findings.
Author: Wouter Hoeffnagel
Photo: Darko Stojanovic via Pixabay
