L’article ci-dessus est l’original en anglais j’en ai mis une partie ci-dessous, mais j’ai bon espoir de voir un article en français sur le sujet, bientôt, ici : http://www.medscape.fr/oncologie/
http://www.thestar.com/news/insight/2013/06/03/toronto_oncologists_present_groundbreaking_paper_on_future_of_cancer_treatment.html (More details in July).
The study — known as IMPACT, for the Integrated Molecular Profiling in Advanced Cancers Trial — involved some 678 patients with incurable cancers and looked at 279 mutations found along 23 of their genes.
And using that tiny gene sampling — just one-thousandth of the typical human complement — the scientists were able to match new, experimental therapies to 23 patients, six of whom have already shown significant improvements.
Desfosses is one of them. She has seen her tumours — lodged now in the lungs, hip, spine and sternum — shrink by 37 per cent since she was placed on her drug trial.
“I feel so lucky to be alive at this time, when we have these kinds of (technologies) available,” Desfosses says.
“The things they can do today, I feel so grateful.”
In the past, much of the oncology field was consumed with magic bullets, with the development of medications or hormone therapies that would target and kill or control tumours over broad populations of patients.
But research over the past decade has shown that the genetic roots of the disease are so dauntingly, so diabolically complex that individual patients may have their own unique cancers — many of which would require personally tailored therapies.
Certainly there have been successes with the broad-based strategy, with many forms of cancer now being successfully treated with a standardized array of drugs or hormones.
But what about patients like Desfosses, who are resistant to the arsenal of therapies oncologists now deploy? Why do these work on some breast cancers, for example, and not others?
The answer, Kamel-Reid says, is in our genes.
Genes are the coding segments of our DNA — the active parts of the genome that produce the proteins that build and control our tissues, organs and even some behaviours.
They are interspaced intermittently along the three-billion base pairs that make up the human genome and number around 23,000 in total.
Cancers can occur when there are mutations in these genes — mistakes in the genetic coding that encourage or cause cells of the breast, or pancreas, or lung, or liver to replicate uncontrollably.
But human genes can range in size from 250 to 81,000 base pairs in length. And what research now makes clear is that it matters a great deal where along the length of these genes a mutation has occurred.
For example, a mutation in one location of a gene known to be involved in liver cancer could produce a much more lethal form of the disease if it occurred in another position up or downstream.
“We see what you call ‘private mutations,’ so they are a different mutation (location) in every person,” Kamel-Reid says.
“It can be hundreds of different mutations throughout the gene.”
The realization that these private mutations existed, and that they could produce more or less curable forms of a similar cancer, was a necessary breakthrough in personalized cancer medicine.
But equally important was the development of genetic sequencing machines that could rapidly and cheaply seek out and locate the private mutations along vast stretches of DNA.
And that’s what Princess Margaret now has. Two, in fact. The size of small beer fridges, the “high throughput” sequencers are located in Kamel-Reid’s rambling, 9th floor lab and can analyze DNA from 16 patients simultaneously in about two and a half days, at a cost of less than $1,000 per patient.
“The technology has advanced such that it’s now feasible to use in a clinical setting,” Kamel-Reid says.
“Previously you could use some of this technology in . . . huge labs that had lots of funding. But it was just not feasible from a cost or workflow perspective to do it in a (hospital) setting.”