Faulty genes linked to prostate and pancreatic cancers, study suggests

Faulty genes already known to increase the risk of breast and ovarian cancer have now been linked to prostate and pancreatic cancers.

A new study has provided the strongest evidence to date of links involving BRCA1 or BRCA2 mutations, and could help those at greatest risk access cancer screening earlier.

The experts found that men who carry a BRCA2 mutation have a 27% risk of developing prostate cancer by the time they are 80 years old – more than double the rate compared to non-carriers.

Among both men and women, carrying either a BRCA1 or BRCA2 mutation more than doubled the risk of pancreatic cancer to 2.5% to 3% by age 80.

These faults were also linked to an increase in the risk of stomach cancer, although the experts said this form of cancer is very rare.

According to the study, mutations in both genes significantly increased the risk of breast cancer in men, but the disease is still very rare, accounting for less than 1% of all male cancer cases in the UK.

The BRCA2 mutation in particular increased this risk by 44 times to 3.8% by the age of 80.

It is estimated that 38 out of 1,000 male carriers of the BRCA2 mutation will develop breast cancer by the time they are 80.

In the past, the mutations have been linked to an increased risk of some other cancers, such as melanoma, but the researchers did not find evidence to support this.

Professor Marc Tischkowitz from the department of medical genetics at the University of Cambridge said: “The link between BRCA2 and prostate cancer and pancreatic cancer is now much clearer, thanks to the data we’ve analysed.

“We have also identified a potential link with stomach cancer, but this is based on small numbers and needs further study.

“Our data suggests that there is no strong link between BRCA2 and melanoma, which may provide greater clarity to BRCA2 gene carriers.

“Overall, the results will add to our knowledge on optimising cancer screening and early detection strategies for people who are known to carry these faulty genes.”

BRCA mutations are uncommon, and affect around one in 300 to 400 people in the population.

Researchers at the University of Cambridge, funded by Cancer Research UK, analysed data from almost 3,200 families with one or more members with the BRCA1 mutation.

They also look at data from almost 2,200 families with the BRCA2 mutation.

Overall, the researchers looked at the links for 22 cancers.

The study is published in the Journal of Clinical Oncology.