A recent study was brought to my attention by a great reader. I highlight it here, not because it is going to change personalized medicine, but because it illustrates some key points.
The study is entitled: "Responses to Online GSTM1 Genetic Test Results among Smokers Related to Patients with Lung Cancer: A Pilot Study" Cancer Epidemiol Biomarkers Prev 2009;18(7). July 2009
This study interested me for several reasons, the first of these was that it involved a hotly debated environmental detoxification gene which has been tested for by numerous nutrigenetics companies for years now.
The second reason it interested me is because it dealt with a population who knows that there family can get cancer when exposed to smoking. I have always wondered for years why there are these families out there who have multiple members with lung cancer, yet everyone in the family seems to keep on puffing.
Are these families full of ignorant people who can't put 2 and 2 together despite years of public health campaigns? Are the genetically or environmentally predisposed to smoking? Does the family have some weird death wish set of genes?
I have always wondered why they do what they do. This study evaluates precisely these families....
It was published on GenomeWeb and on several blogs as well as several news outlets with titles like:
1. Online Genetic Testing Appears to have Benefits
2. Study Suggests Online Genetic Test May help Smokers Quit
3. Possible Benefit From Online Genetic Testing For Lung Cancer
What they did: They identified relatives of Patients with stage IIIB/IV lung cancer who were receiving care in the Thoracic Oncology Clinic at the H. Lee Moffitt Cancer Center and Research Institute were identified. So in essence, patient who have pretty bad cancer, their relatives....who likely know that it is a bad cancer.
They tested the relatives for GSTM1 genotypes. Which is pretty interesting to me, because as the study admits, the Odds Ratio for Lung cancer in this null population is 1.15 to 1.17. essentially as close to one as you can get......
Which means that this association is pretty freaking weak......
So in essence they are going to clinically LIE to the person tested and tell them they had a higher risk.
Oh and BTW, they only analyzed 44 people.....Hardly a useful sample size, especially when 96% were white.....and 22% were college educated, hardly the 23andMx population......
What they found.
1. Smokers with the at risk profile GSTM1 nulls, remembered at 6 months that they had a "higher" risk.
2. Smokers with the normal risk, forgot that more often.....roughly 50% remembered that they were at "lower" risk
3. Both parties "believed" the test results equally........
4. There were NO SIGNIFICANT DIFFERENCES in uptake of the smoking cessation services between those who received the GSTM1-present and GSTM1-missing test result.......
5. At the 6-month follow-up, the proportion of smokers in each group who reported medication use did not differ significantly.
6. Perceived risk for cancer was the SAME in both groups
7. There were no significant differences over time in confidence in ability to quit smoking between the GSTM1-present and GSTM1-missing relative smokers.
"This observational study was not sufficiently powered for nor was it a study aim to assess smoking cessation as an outcome."
Obviously as it only had 44 participants in it........ So I am freaking left asking myself "Where in the HELL is the benefit?"
There are a ton of limitations which prevent this article from even being a study. It is an observation of a very, very small cohort......I consider this as statistical NOISE.........
But, the authors try to save themselves by stating "However, these limitations need to be balanced against the strengths, which include this study being the first, to our knowledge, to offer genetic testing for a common gene variant online."
Are you serious? Strengths? Maybe Strength, but I think that there is other research currently going on involving online genetic testing.
Maybe not published, but there is ongoing......
Some important points that I take from this paper........
1. DTC Genomics has a huge PR machine that will trick papers into writing bull$hit headlines and false claims....I.E. you cannot trust a single thing published in the lay press about genetic studies EVER!!!!!
2. How does a study with 44 people get noteworthy accolades for proving that essentially a single gene variant, weak association, does nothing in terms of empowering patients.....IFF you accept that this study wasn't just noise......
3. The DTC companies offer THOUSANDS of these little polymorphisms......if the people with normal results can't remember that they are at "REDUCED" risk from ONE, how can we expect people to remember THOUSANDS.....BTW, this is essentially like telling a patient that if they eat a ONE cheeseburger from McDonalds on Tuesday July 16th that they are at risk of a heart attack in the next 5 years......Statistical Bull$hit with ZERO Veracity
4. People will cling to the tiny shred of suspect evidence of the 6 of 44 who quit smoking.......% had the GSTM1-Null genotype, which if you look at statistics is likely pure chance as 50% of the pop is NULL.......Hmm whats the odds of 5/6 being null....I can't believe they even mentioned this in their paper.....What a crock!!!!!
The Sherpa Says: Just because it is published in a journal doesn't make it Good Science. Hell, it doesn't always make it Science at all.......Shame on the press and the bloggers who hyped this piece of garbage.......
Friday, July 3, 2009
Smoke or $h!t gets in your eye!
Posted by
Steve Murphy MD
at
5:46 AM
5
comments
Labels: 23 and me, DNA direct, genovations, great smokies, gstm1 null, Helix Health of Connecticut, navigenics, nutrigenetics, smoking cessation
Thursday, August 9, 2007
Personalized Medicine....What about Prevention?
A recent study published and talked about everywhere around the web indicates that our lifestyle matters. If we would just follow these five things, we would save thousands of lives.......How will we carry out personalized medicine if we cannot follow simple preventative measures.
Here's what the Partnership for Prevention Suggests:
The biggest impact would be saving 45,000 lives by encouraging more adults to take a daily low dose of aspirin to prevent heart disease, said the report which was sponsored by the US Centers for Disease Control and Prevention, the Robert Wood Johnson Foundation and the WellPoint Foundation.......
Other measures that would save tens of thousands more American lives every year include more adults getting flu shots
- 45,000 lives saved from more adults taking a daily low dose of aspirin (current take up rate is below 50 per cent).
- 42,000 more lives saved by offering smokers professional help to quit, including medication (current level is below 28 per cent).
- 14,000 more lives saved by more adults having regular screening (current level is below 50 per cent).
- 12,000 more lives saved by more adults aged 50 or over having an annual flu shot (current level is below 37 per cent).
- Nearly 4,000 more lives saved by increasing the number of women aged 40 or over who have been screened for breast cancer in the last two years (current level is 67 per cent).
What about the potential for genetics to promote public health? Well, Wylie Burke is a little less optimistic than myself.
The Sherpa Says: What would you do if you knew you were at risk? Would you get the flu shot? What about frequent cancer screening? Taking an aspirin? Or even quitting smoking? I hope with the right Sherpa, you would.....
Posted by
Steve Murphy MD
at
6:20 PM
3
comments
Labels: drudge report, preventative medicine, prevention, quitting smoking, smoking, smoking cessation
Tuesday, June 26, 2007
The Confusing Thing About Association Studies.
- Long Term Aspirin use prevents cancer incidence in colon 32%, prostate 19%, and breast cancer 17%* (statistically non-significant). There is some molecular evidence of this in colon cancer. But not the others....... The catch is that you have to use aspirin adult dose for >5 years. Why? Like most association studies.....No one knows. What good is that?
- Hormone replacement therapy increases Ovarian cancer incidence This study called the Million Women Study is a large cohort of British women. 948,576 postmenopausal women were assessed for ovarian cancer incidence. Users were 20% more likely to develop Ovarian Cancer. 1 in 5, that seems small, but in a million women (well......just 52k shy) that's alot of cancer!!! Especially such a nasty killer. But here's the kicker....
- Oral Contraceptive hormones Reduce Colorectal Cancer risk! Wait a second.....Aren't these female hormones too? This study shows an almost 40% reduced incidence of colon cancer in these women from the Women's Health Study. Perhaps this has to do with dosage? But Who Knows....It's an association study!!!
- Smoking Cuts Risk of Parkinson's Disease So that is what the media says about this study. Ok so now you have got me flipping out. No mechanism, No pathogenesis, No explanation.... Smoking kills, but at least it reduces your likelihood of ALSO having Parkinson's. Almost a 40% reduction in the likelihood of having Parkinson's. How? Who Cares....It's an association study! This kills me. The people could have predisposition genes for nicotine addiction/taste/etc which also have some salutatory effects. I do not think that smoking is what saves these patients brain cells!!!! But that's not what the press will tell you.
The Sherpa Says: What is sold as a good piece of science is quite often a piece of something else! Just because it was toiled over and hard work to develop it was done does not make it true, correct or even appropriate. I am here to say.....If it sounds fishy it probably smells fishy too. Throw out association studies until you have a reason for the association!!!
Posted by
Steve Murphy MD
at
3:58 PM
2
comments
Labels: brain cancer, Breast cancer, Colon cancer, gene sherpa, hormone therapy, parkinsons disease, quitting smoking, smoking, smoking cessation, The Gene Sherpa