Genetic mutations that drive cancer identified

Scientists have identified 127 repeatedly mutated genes that drive the growth of a range of cancers in the body.
Examining 12 major types of cancer, scientists at Washington University School of Medicine in St Louis have identified the repeatedly mutated genes that appear to drive the development and progression of a range of tumours in the body.
The discovery sets the stage for devising new diagnostic tools and more personalised cancer treatments.
The research shows that some of the same genes commonly mutated in certain cancers also occur in seemingly unrelated tumours.
For example, a gene mutated in 25 per cent of leukemia cases in the study also was found in tumours of the breast, rectum, head and neck, kidney, lung, ovary and uterus.

"This is just the beginning. Many oncologists and scientists have wondered whether it's possible to come up with a complete list of cancer genes responsible for all human cancers. I think we're getting closer to that," said senior author Li Ding of The Genome Institute at Washington University.

The new research analysed the genes from 3,281 tumours - a collection of cancers of the breast, uterus, head and neck, colon and rectum, bladder, kidney, ovary, lung, brain and blood.
In addition to finding common links among genes in different cancers, the researchers also identified a number of mutations exclusive to particular cancer types.

While the average number of mutated genes in tumours varied among the cancer types, most tumours had only two to six mutations in genes that drive cancer. This may be one reason why cancer is so common, the researchers said.
"While cells in the body continually accumulate new mutations over the years, it only takes a few mutations in key driver genes to transform a healthy cell into a cancer cell," noted Ding.
TP53, an already well-known cancer gene, occurred most commonly across the different tumour types. It was found in 42 per cent of samples and routinely was associated with a poor prognosis, particularly in kidney cancer, head and neck cancer and acute myeloid leukemia.

Another gene, BAP1, also was linked with an unfavourable prognosis, especially in patients with kidney and uterine cancer.
However, mutations in the breast cancer gene BRCA2 were associated with improved survival in ovarian cancer, while errors in IDH1 were linked to an improved prognosis in gliobastoma, a particularly aggressive brain tumour, and in other cancer types.
The study was published in journal Nature.