Scientists map gene sequence for cancers

Scientists have mapped the entire genetic sequence of breast and colon cancers, which could lead to better ways to diagnose cancer in its early, most treatable stages, as well as further develop personalised treatments.

The potential this research represents is limitless as knowledge of these cancers on a genetic level as well as how the genes interact with one another is key to treating and defeating this killer disease.

Scientists from the Johns Hopkins Kimmel Cancer Center have produced a genetic map that shows nearly 200 mutated genes, most previously unknown, help tumours emerge, grow and spread.

The researchers discovered that mutated genes in breast and colon cancers were almost completely distinct, suggesting different pathways for the development of each of these cancer types.

Each individual tumour appeared to have a different genetic blueprint, which could explain why cancers can behave very differently from person to person.

It also gives rise to the concept of personalised treatments to treat this variation in the disease.

"No two patients are identical," said co-author Dr Victor Velculescu in the report.

Numerous genes play a role in drug response and toxicity, introducing a daunting level of complexity into the search for candidate genes.

Personalised medicine or pharmacogenomic analysis can identify disease susceptibility genes representing potential new drug targets. This may well lead to novel approaches in drug discovery, an individualized application of drug therapy, and new insights into disease prevention.

Indeed, previous cancer gene discoveries have already led to successful detection and treatment strategies.

The breast cancer drug Herceptin targets a breast cancer cell receptor made by the Her2-neu gene. Blood tests for hereditary bowel cancer are based on the APC gene.

The study is published in the latest edition of Science magazine.