Our experience bears out the importance of renaming hereditary breast and ovarian cancer (HBOC) as King syndrome (C. C. Pritchard Nature 571, 27–29; 2019). National and international guidelines urgently need to extend their criteria for BRCA testing to include males with a family history of prostate or pancreatic cancers. Examples include those issued by the European Society for Medical Oncology and the UK National Institute for Health and Care Excellence.

Men carrying mutations in BRCA1 and/or BRCA2 can develop melanomas or cancers of the breast, pancreas or prostate. At the European Institute of Oncology, we tested far fewer men than women for mutations in these genes (357 versus 4,728 since 2001). Seventy-three of those men were probands, the first in their family to test positively for such mutations; the other 284 were involved in cascade screening, which is the testing of blood relatives of people with specific genetic mutations. Compared with women, the overall testing ratio is 1 in 13, or 1 in 53 for probands only. Most of the male probands (63 out of 73) had breast cancer; 8 had only non-breast tumours (11%). Notably, 40% of patients with prostate cancer had a BRCA mutation.

The most recent guidelines from the US National Comprehensive Cancer Network recommend BRCA testing for men with metastatic or advanced prostate cancer and a family history of the disease (go.nature.com/2jk6fwb). Broader genetic data on males will improve patient diagnosis and management, and increase treatment and clinical-trial options.