Monday, December 16, 2013

ASH: Blood Cancer Blood Test

This is about a week old now, but it's worth taking a look at: a post-ASH press release from Sloan-Kettering touting its new blood test, to be used as a diagnostic tool for blood cancers.

The blood test will look for 400 variations in genes that signal a blood cancer. It could, for example, show that chromosomes 14 and 18 have switched places, which would indicate that the patient has Follicular Lymphoma. Those 400 different variations can detect a variety of lymphomas, leukemias, and myelomas.

Here's why it's important: because it will be used as a tool not only for diagnosis, but for treatment decisions as well. As genetic research gets more and more sophisticated, we are finding that cancers that seem the same under a microscope might actually be different if viewed on a genetic level (that is, much more closely than we can see with a simple microscope).

To give you a Follicular Lymphoma example, a key sign of FL is the 14;18 translocation, with those two chromosomes switching places and causing all kinds of problems -- it basically shuts of the bcl2 protein that tells the cells to die. However, Follicular Lymphoma also sometimes shows another switching involving the protein BCL6. Now, a standard look through a microscope will show that the cells from a biopsy look the same -- like Follicular Lymphoma cells. But only a genetic analysis will show that there is either one or two of those chromosome switches taking place.

Now imagine that we have a patient diagnosed with Follicular Lymphoma who had the new Sloan-Kettering blood test. Her doctor knows that the 14;18 chromosome is often dealt with successfully with something like Bendamustine. But imagine that this doctor also knows that early results from a clinical trial for a new treatment (let's call it Bobimab) has shown remarkable results if the patient has BOTH translocations. The doctor knows that this patient would be an excellent candidate for that trial because the test shows both translocations.

Much less guessing. Much more targeted treatments. This is what personalized medicine is supposed to be all about.

(And if anyone from a pharma company or a university lab is reading, please feel free to name your next Monoclonal Antibody after me. Bobimab is much less intimidating than what you usually name things, with all of those Vs and Xs and Zs.)

For now, the test will take 3-4 weeks to get results back. For someone with Follicular Lymphoma, that's not a big deal. For someone with a more aggressive blood cancer, treatment will have to start right away, so maybe it would be more useful for a second round of treatment. I can also see the test getting easier over time, with results coming back faster (though that isn't something that Sloan-Kettering is promising).

All in all, I think this should be bigger news than it is. All or most of this information is already available, but I think this is the first test that can detect so many variations at once. And I'm guessing the test is scalable: as more genetic information is discovered, it can be added to the test.

Very cool stuff.

1 comment:

Lewis N. Clark said...
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