Wednesday, April 30, 2008

The New BRCA and SubSegments of a Segment

First and Foremost,
To all women who have hereditary patterns of Breast Cancer, but have a negative BRCA work up....there is new information which deCode has released in Nature Genetics. I was very excited about this and look forward to some significant replications.

From a recent MarketWatch report
Common variants previously discovered by deCODE on chromosomes 2q35 and 16q12 are together involved in an estimated 25% of ER+ breast cancers. The analysis in today's paper also reveals that a fourth known set of variants, located on chromosome 10q26 and accounting for approximately 16% of breast cancers, appear to confer risk exclusively of ER+ tumors. deCODE is applying these variants as the basis for a DNA-based reference laboratory risk-assessment test the company plans to launch in the coming months

The rationale for such testing is all the more compelling in ER+ cancers, since drugs such as tamoxifen have been shown to be successful in preventing as well as treating these cancers, and other drugs now in development may prove to be safe as long-term prophylactic therapy as well.

This is huge news. Imagine being able to pinpoint risk for ER+ breast cancer. We already have medications which can reduce the risk of these cancers!!!!

I think the excitement was there until......I looked at the Odds Ratio! So to recap, "New genes for breast cancer, but the increased risk is only 20% above the population". In fact, that was the largest effect. So I want to say Ho-Hum about these tests and probably will. But, the American Cancer Society is recommending MRI for those who have an increased risk for breast cancer. Notably once that risk is 25% about the population risk. This MIGHT put people into this category....I say MIGHT!

So this leads me to my next question is this a medical test? Or a recreational genomics test?

A report by BioArray News..

By Justin Petrone
Hoping to insulate themselves from regulatory pressures from at least one state health agency, some direct-to-consumer genetic testing services may position themselves as disease-risk testers while others may focus more on recreational genetics, such as determining genetic ancestry.

Thus, I ask what testing company could insulate themselves when it is obvious that even ancestry testing can reveal medical data!!! Personally, I feel that when applied...any genetic test can identify medical risk.

So is all genetic testing medical? To subsegment in a hope to protect from legislation is disingenuous at best. The government is going to come down hard on these companies... All in the name of protection of the public. Why? Because the public like the physician is not quite ready for this.

Blaine points this out over at The Genetic Genealogist.
Some concept questions were failed by over half of participants. Which only reinforces the public's lack of understanding and susceptibility to hype. Much like the WSJ hype on this finding. Shame on Marilyn over at the WSJ for not reporting the mild increased risk and instead lumping this in with the BRCA gene risks!

The Sherpa Says:
The public is anxious to buy into hype. Companies are anxious to build hype and it seems all too convenient that the press is willing to help. The path is getting complicated. Let's use the principles on this one. 1. Await replication 2. An Odds Ratio less than 2 is not that impressive 3. Don't believe the reports, unless translated by a professional.

1 comment:

Anonymous said...

Are all genetic tests medical genetic tests? Gee, doesn't DNA lead to RNA and RNA leads to protien? As such, when a mutation occurs that changes the function of a protein and a abnormaility in the function of the protein leads to a disease, of course any genetic test that tests for mutations is a genetic test. There isn't any way around this very simplistic concept.