On July 9, 2026, researchers at the University of British Columbia announced they have identified a new form of hereditary prostate cancer that, while rare, can cause aggressive disease at a young age. The discovery paves the way for genetic testing programs that could help identify at-risk families and support early cancer detection. While most cancers are caused by genetic changes that accumulate over a person’s lifetime, about five to 10 per cent are linked to inherited mutations that can be passed from one generation to the next. 

The best-known examples are mutations in the BRCA1 and BRCA2 genes, which greatly increase the risk of developing certain cancers, including breast, ovarian, pancreatic and prostate cancer. Genetic testing for BRCA mutations has transformed cancer care, helping people at risk access early screening and prevention programs. 

The new study, published in Cancer Discovery, identifies another gene—called CDK12—that could provide a similar warning sign for aggressive prostate cancer. The researchers analyzed genetic data from more than 4,500 people with aggressive prostate cancer and identified five unrelated men carrying inherited CDK12 mutations. All five developed metastatic prostate cancer between the ages of 44 and 62.

The study was an international collaboration between researchers at UBC, BC Cancer, Vancouver Coastal Health Research Institute and the University of Washington, as well as institutions in Australia, the Netherlands, Spain and Belgium.  

Until now, scientists believed harmful CDK12 mutations only occurred spontaneously within tumour cells and could not be inherited. To confirm that the inherited mutations were causing the cancer, the researchers looked for a distinctive genetic fingerprint left behind when CDK12 stops working. “The tumours provided us with a genetic signature that pointed directly back to CDK12,” said lead author Dr. Sofie Tolmeijer, a postdoctoral fellow in the Wyatt lab. “It gave us compelling evidence that these inherited mutations were playing a direct role in causing their cancer.” 

Although inherited CDK12 mutations were found in only about one in every 1,000 people with aggressive prostate cancer, the researchers estimate they could affect hundreds of families worldwide.  

The study also raises the possibility that inherited CDK12 mutations may increase the risk of ovarian cancer. Several of the patients had family histories of ovarian cancer, and the researchers identified an additional person with ovarian cancer who carried an inherited CDK12 mutation and whose tumour showed the same characteristic genetic changes.

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