Good lifestyle extra important for those who have previously had testicular cancer
Published 12.12.2019
Researchers have previously observed that testicular cancer survivors may have an increased risk of developing so-called metabolic syndrome later in life, but why and how this happens has so far been unknown.
"Metabolic syndrome is a collective term that includes overweight and increased waist circumference, high blood pressure, high insulin levels and unfavourable cholesterol levels," explains Trine Rounge at the Cancer Registry of Norway, last author and responsible for the article.
These disorders increase the risk of developing diabetes, heart disease, narrowed arteries in the legs or having a stroke.
"It is of course unfortunate that cancer and treatment for cancer can increase the risk of long-term effects later in life, but fortunately these late effects can be largely prevented," says project manager and researcher at the Cancer Registry, Tom Grotmol.
This research project is supported by the Norwegian Cancer Society.
Testicular cancer is the most common cancer among young men.
Found changes in epigenetics
Researchers at the Cancer Registry of Norway, together with national partners, have studied a group of men several years after they were treated for testicular cancer.
The researchers took blood samples from this group 16 years after treatment and isolated the DNA to see if the epigenetic signature had changed.
Epigenetics is the knowledge of how genes through different influences can be activated or deactivated, even though the DNA sequence itself does not change. This is still a relatively young and unexplored field, where there is still much to learn.
The Cancer Registry's research shows that there are more areas of DNA irregularities among men who have been treated for testicular cancer, compared to men who have not undergone such treatment. The areas that were particularly susceptible to changes were precisely the same areas that are related to the development of metabolic syndrome.
"This means that we may have found a possible connection for why and how testicular cancer survivors are more susceptible to metabolic syndrome," says Marcin Wojewodzic, systems biologist and postdoctoral fellow at the Cancer Registry.
Most common among young men
Testicular cancer is the most frequent cancer among young men, and most of those affected are in their 20-30 years. Half of those who get testicular cancer are younger than 36 years old.
Annually there are about 300 new cases of testicular cancer among men in Norway – in 2018 the number was 316.
The graph shows the age distribution for testicular cancer in the period 2014-2018, in age-specific rates, i.e. the number of cases per 100,000 men. Testicular cancer occurs most frequently among men in their 30s. Source: Cancer Registry Cancer Registry of Norway's statistics bank
The cause of the disease is largely unknown, but hereditary factors are of considerable importance.
"Fortunately, the prognosis for testicular cancer is very good – survival is actually almost 99 percent. The main reason for this is that those who have spread of the disease have a very good effect from the chemotherapy cisplatin. Since it came on the market about 40 years ago, the outlook for these patients has steadily improved, says Wojewodzic.
But – cancer treatment can come with a price, and as more and more people survive their cancer diagnosis, and live for a long time as former cancer patients, it becomes increasingly clear that some also experience late effects as a result of the treatment.
The figure shows developments in incidence (dark blue), mortality (light blue) and five-year relative survival among men with testicular cancer. Source: Cancer in Norway 2018
- Good lifestyle choices are especially important
Within cancer care, there is therefore a lot of research on both the extent and causes of late effects. And here it is that the researchers from the Cancer Registry of Norway have now contributed a small piece to the puzzle when it comes to testicular cancer.
With regard to metabolic syndrome in former testicular cancer patients, such disorders can be prevented, but patients should perhaps be prepared to be extra disciplined.
"Thanks to cisplatin therapy, these patients have already won a new life. Now they have to take care of themselves and reduce their risk of developing metabolic syndrome. They can do this through physical activity, a healthy diet and proper body weight. In other words: if you have had testicular cancer and been treated with cisplatin, eat healthy and in the right amounts, recommends Wojewodzic.
