DNA map offers hope on cancer treatments

Cancer will become a manageable disease rather than a death sentence thanks to a revolutionary treatment that will be available within five years, British specialists predict.

All patients will soon have their tumour’s DNA, its genetic code, sequenced, enabling doctors to ensure they give exactly the right drugs to keep the disease at bay.

Doctors hope it will be an important step toward transforming cancer into a chronic rather than fatal disease.

The technique could enable terminally ill patients, who can currently expect to live only months, to carry on for a decade or more in relatively good health, according to specialists at the Institute of Cancer Research in London.

“We should be aspiring to cure cancer, but for people with advanced disease, it will be a question of managing them better so they survive for much longer — for many years,” said Professor Alan Ashworth, chief executive of the institute.

“Cancer often appears in people who are old, and if we can keep them alive long enough for them to die of something else, then we are turning cancer into a chronic disease.”

Ashworth said that under- standing of how different cancers were caused by different genetic triggers was building “incredibly rapidly.”

Genetic profiling of tumours is already used to some extent, but current methods only look for a few genes. Women with advanced breast cancer are tested to see if their tumours have a particular variant of the HER2 gene, which causes a fifth of cases.

Those with it are given Herceptin, but the same drug would do no good for those without the gene variant.

Advanced melanoma patients with a particular gene mutation are prescribed Vemurafenib, a pill that has been shown to increase survival, on average, from 9.6 to 13.2 months, and help patients feel much more energetic.

But average survival times hide massive variations. One patient at the Royal Marsden in Chelsea, where the institute is based, has survived 10 years so far with advanced breast cancer on Herceptin.

Ashworth said that such cases were the exception. But he added:

“We would hope that they will become the norm. By actively profiling patients who respond well, and sequencing their genomes, we can find the genes that are responsible for that.”

The institute wants to build a DNA database to identify lots of genes responsible for cancers.