British researchers have discovered five genetically distinct types of prostate cancer tumors after sifting through hundreds of healthy and cancerous prostate tissue samples collected from more than 250 men, and tracking the activity of 100 genes associated with prostate cancer. The results show promise for tailoring specific treatments for patients with this disease.
“We already divide men into different risk groups,” based on a variety of tests, including a PSA blood test, X-rays, and MRI scanning, explained Alastair Lamb, MD, a clinical lecturer with the Cancer Research UK Cambridge Institute and the study’s lead author, in a news video that summarized the study results.
“What we’ve done here is we’ve undertaken an indepth analysis of the genetics—the genes that have turned on and off in a large group of men with prostate cancer and we’ve effectively added that to what we already know about prostate cancer in order to better divide men into these risk groups which do poorly or well in terms of outcome,” said Lamb.
Findings were published in the journal EBioMedicine. For this study, researchers conducted integrated genomic profiles of 259 men with localized prostate cancer who were divided into two cohorts: a discovery and a validation group. More than 480 benign and cancerous tumor samples were taken from the study participants.
The men were divided into “5 molecular clusters of clinical risk based on copy number and gene expression profiling of 100 key genes,” the article explained. The 100-feature gene set included protein kinases MAP3K7, MYLK2, 455 RIPK2, PTK2B, MELK, and ACVR1 and transcription factors TRIM13, 456 GTF2E2, PHF11, ERCC3, and GTF2F2.
In separate discovery and validation sets of 125 and 103 participants, researchers “identified five separate patient subgroups with distinct genomic alterations and expression profiles,” based on the 100 types of discriminating genes, according to the article.
The researchers called their findings “clinically significant” in that they should help urologists recommend therapies that are appropriate for men who fall into various risk categories for prostate cancer. Knowing the specific characteristics of a patient’s tumor will assist physicians in choosing a treatment that works best for that individual patient, Lamb said in a statement issued by Cancer Research UK.
“The next step is to confirm these results in bigger studies and drill down into the molecular 'nuts and bolts' of each specific prostate cancer type. By carrying out more research into how the different diseases behave we might be able to develop more effective ways to treat prostate cancer patients in the future, saving more lives,” Lamb said.
About 41,700 cases of prostate cancer are diagnosed in the United Kingdom annually, making it the most common form of men’s cancer in the UK. In the United States, the National Cancer Institute estimates that 233,000 men received a prostate cancer diagnosis in 2014, with 29,500 dying of the disease.