The most common type of prostate cancer has two different ways of developing in the body, researchers have found, opening up new possibilities for identifying which patients need treatment.
Prostate cancer is the most common form of cancer in men, with one in eight diagnosed with the disease during their lifetime. Most prostate cancer are adenocarcinomas – a type of cancer that forms in the glandular tissue that lines certain internal organs. But while the disease can kill, the risk for many patients is low.
“The key problem in prostate cancer is identifying that 15% of men who will have more aggressive cancers that will spread to other organs and actually cause death,” said Prof David Wedge from Manchester. Cancer Research Center, which led the study.
He said: “If we can identify those men, we can give them more robust treatment … and you can leave the other 85% of men alone. This is beneficial because the surgery itself has many side effects.”
Now Wedge and colleagues say they’ve found a new way to classify adenocarcinomas that may help them do just that.
Write in the journal Cell genomics, the researchers report how they sequenced the genomes of 159 patients with adenocarcinoma of the prostate. They then used three different approaches – including artificial intelligence (AI) – to analyze patterns within the genomes, including the way DNA was damaged and the order in which certain genetic changes occurred.
All three approaches pointed to the same result: that the prostate cancer fell into two main groups – or “evotypes” – related to how they changed over time in the body and the mechanisms involved.
Most importantly, when the researchers looked at the results of blood tests taken after the patients underwent treatment, they found that those with one evotype were twice as likely to show signs of a recurrence of the disease as those with the other.
Wedge said, “Often those men will actually have metastases, [so] the cancer has already spread to other organs.”
The team says the findings suggest that a genetic test can be used to determine whether patients with adenocarcinoma of the prostate have the more or less aggressive evotype, so that treatment can be better tailored to them, and possibly given sooner.
Wedge said it is now important to investigate whether the type of evotype might be associated with factors such as the age and ethnicity of the patient, while the team is also looking at whether other types of cancer have evotypes.
Prof Joe O’Sullivan, a consultant prostate cancer oncologist at the Northern Ireland Cancer Center in Belfast, who was not involved in the work, welcomed the study.
He said: “The identification of two different subtypes of prostate cancer according to the genetic evolution pathway may aid in both stratification of treatment as well as potentially opening up new possibilities for drug discovery.”
