Study uncovers six cancer susceptibility genes

Scientists at deCODE genetics/Amgen, and their collaborators have discovered six novel genes with rare germline variants that associate with cancer risk. The findings are published today in Nature Genetics under the title “Gene-based burden tests of rare germline variants identify six cancer susceptibility genes”.

A subset of cancers arises in individuals who are born with rare sequence variants that significantly alter their cancer risk. The discovery of such variants, like those in the BRCA1– and BRCA2 genes, has led to improved early cancer detection and the development of targeted therapies, ultimately reducing the cancer burden and improving prognosis of those carrying these mutations.

In this study, the scientists analyzed three large genetic datasets from individuals of European descent, including 130,991 cancer patients and 733,486 controls. Through a gene-based burden association analysis across 22 different cancer types, they found four novel genes associated with a risk of developing cancer; the pro-apoptotic BIK for prostate cancer, the autophagy involved ATG12 for colorectal cancer, TG for thyroid cancer, and CMTR2 for both lung cancer and cutaneous melanoma. The relative increase in cancer risk conferred by these variants was substantial (90-295%), but it should be noted that the design of the study does not allow accurate assessment of absolute lifetime cancer risk.

Additionally, the researchers found the first genes with rare variants that are associated with a decreased risk of cancer. Specifically, loss of AURKB was found to protect against any cancer type, and loss of PPP1R15A was associated with 53% lower risk of breast cancer. This suggests that inhibition of PPP1R15A may be a therapeutic option for breast cancer.

The study revealed new insight into the biological mechanisms involved in cancer predisposition that will hopefully lead to better screening and treatment strategies.