3 December 2011
How will we treat the cancer of the future? Sequence a patient’s genome, and the cancer’s!
If you just let out a gasp of incredulity, that’s perfectly natural and healthy. If you don’t know what a genome is, no worries. A genome is the sum of all genes in an organism. You have about 28,000 genes in your genome. Every gene is a sequence of DNA made up of the base pairs A, T, C, and G, so a strong of DNA might read: ATGTTCGAA. If you were to store your genetic sequence in a simple text file, it would take up about 1.5 gigabytes of space!
The New York Times reports that in July of 2007 the cost of sequencing an individual’s genome was about $8.9 million. On Wednesday The Times reported that the cost of sequencing is approaching $1000.
So what’s the big deal? Your genome contains just about everything about you that can and will be determined by your genes. That includes what types of cancer you could likely develop in your lifetime. But that’s not where it stops. In a scenario only five years ago that seemed like science fiction, it might be possible in the next decade to sequence both a patient’s genome, and the genome of their cancer!
As I’ve echoed in this blog many times, cancer is not one disease, but a collection of many different diseases with overlapping etiology, outcomes, and genetic underpinnings. This makes it frustratingly hard to treat, because two cancers that appear identical under the microscope might actually respond to very different therapies.
If treating cancer is a game of oncological chess, having the cancer genome would be like knowing the next five moves of your opponent. It would be like seeing not only the boxer’s next punches, but knowing in advance where he will let his guard down. It would be like building the ship outside of the bottle.
However, the next technological caveat, as Andrew Pollack discusses in his NY Times article, is not our ability to sequence genomes, but process and analyze them. And, even if you knew where the next five punches were going to come from, would you have the tools to exploit it? Cancer genome sequencing will not be the cure by itself. But, it is a tool so powerful that we cannot yet fully comprehend its scope.
Just five years ago this scenario was distinctly in the realm of science fiction, something I might consider in 10-20 years. I never dreamt that we’d be on the cusp in 2011!