Archive for the ‘cancer’ Category

We are constantly bombarded with alarming announcements about heart attack risks.  Many hundreds of billions of dollars are spent annually in multiple ways  trying to avoid dying from a heart attack.

It is a bit shocking to actually see what the 10 year heart attack mortality risk looks like.  I don’t know what your reaction will be but my was, “Huh, wow, that’s not such a big deal.  Maybe I should just relax, live as healthily as possible and ignore all the medical screaming and shouting.

I have used the data table found on page 128 in the very readable, and useful book Know Your Chances by Woloshin, Schwartz and Welch.

About the illustration-

There are 100 men icons. The darker icons represent the number of 65 yr old nonsmoking men who will die of heart attack before they become 75 yrs old. (5.2  of this group will die of heart attack in the next 10 yrs.)

 

Now let’s do the same sort of chart for a 100 men who smoke.  In this case, the data claims that 7.4 of these 65 yr old smokers will die of heart attack before the age of 75.

Here is a link to a pdf which has downloadable risk charts:  Health Risks by Age, Sex and Smoking Status

Overdiagnosis in Cancer

The full article is hiding behind a pay wall but at least this abstract can give us some idea of the possible degree of over-diagnosis in cancers.

I don’t understand why the National Cancer Institute is putting this information behind a pay wall.  

from the Journal of the National Cancer Institute

written by H. Gilbert Welch, William C. Black

We estimated the magnitude of overdiagnosis from randomized trials: about 25% of mammographically detected breast cancers, 50% of chest x-ray and/or sputum-detected lung cancers, and 60% of prostate-specific antigen–detected prostate cancers. We also review data from observational studies and population-based cancer statistics suggesting overdiagnosis in computed tomography–detected lung cancer, neuroblastoma, thyroid cancer, melanoma, and kidney cancer. To address the problem, patients must be adequately informed of the nature and the magnitude of the trade-off involved with early cancer detection. Equally important, researchers need to work to develop better estimates of the magnitude of overdiagnosis and develop clinical strategies to help minimize it.

via Overdiagnosis in Cancer — Welch and Black, 10.1093/jnci/djq099 — JNCI Journal of the National Cancer Institute.

 

As Yogi Berra prophetically declared, “Prediction is hard, particularly about the future.”

Just because a theory sounds great does not mean that it will actually work so well.  Maybe, eventually targeted therapy will become very effective but for now it should be advertised as it really is.

from the New York Times

Dr. Linda Griffith was at a conference in Singapore in early January when she felt a lump in her breast. She assumed it was nothing — a cyst. And anyway, she had no time for it. She was returning on a Sunday night and the next Tuesday morning was leaving for a conference in Florida.

But she had a mammogramultrasound and biopsy within hours of getting off the plane. The news was not good: she had cancer.

Then the complications began. Dr. Griffith, director of the Center for Gynepathology Research at M.I.T., had a test to see whether her tumor had extra copies of a protein, HER2. If it did, it would respond to a drug, Herceptin, which blocks the protein and stymies the tumor’s growth.

Drugs aimed at disabling proteins that spur cancer are, many oncologists say, the future of cancer therapies. Only a few are available now but almost every new drug under study is designed to disable cancer-fueling proteins.

But these so-called targeted therapies are only as good as tests to find their protein targets. And while most patients do not yet know it, those tests can be surprisingly unreliable.

Acknowledging the problem, cancer specialists on Monday announced new testing guidelines for one protein target, but as new targets are identified, the problem continues to grow.

The test on Dr. Griffith’s tumor was negative. Or was it? One small area of her tumor stained chocolate brown, indicating lots of HER2. The rest was a cream color, indicating no extra HER2 protein.

Yet her treatment hinged on this result. A HER2 positive tumor has a bad prognosis. Herceptin can make that prognosis good, reducing the chances that the cancer will come back by 50 percent and reducing a woman’s risk of dying by 40 percent.

But Herceptin, costing $42,000 a year wholesale, causes flulike symptoms and also has a rare, serious side effect, severe heart damage that can even be fatal.

 

Cancer Fight – Unclear Tests for New Drug – NYTimes.com.

Here is an earlier study from Italy which also questions the wisdom of stopping clinical trials early because of  the therapy seems “beneficial.” This is also from the Science Daily site.

“In a  new study,* Italian researchers analysed 25 randomised controlled clinical trials that had been stopped early because they had started to show a benefit to patients and found that the numbers had increased dramatically in recent years. They warn that this could lead to a systematic over-statement of the effects of treatment, and that patients could be harmed by new therapies being rushed prematurely into the clinic.

Out of 14 trials stopped because they started to show benefit to patients and published between 2005-2007, the researchers found that 11 (79%) were used to support an application for marketing authorisation at the European Medicines Agency (EMEA) and the United States Food and Drug Administration (FDA).

“This suggests a commercial component in stopping trials prematurely. In fact, this strategy (i.e. stopping trials early for benefit) could guarantee quicker access to the market for companies. On the other hand, a quicker clinical drug development may lead to an ‘immature’ benefit/risk balance of new drugs,” Dr Giovanni Apolone, one of the authors explained.”…..

via Stopping A Cancer Trial Early: Is It For The Benefit Of Patients Or Pharmaceutical Companies?.

I regret to report that very little progress has been made in curing cancer since Nixon declared a “war on cancer” over 40 years ago.  Unfortunately, in spite of all the talent and billions of dollars spent since the 1950’s, we are pretty much where we started.  The New York Times has started a series of articles on this issue.

Although lifestyle factors are no guarantee of avoiding cancer, seems to me that they provide our best chance for prevention and better survival rates.

Here is a link to the first article in the NYT series and a few excerpts: when you link to the original article, be sure to click on the  graphics link on the left

http://www.nytimes.com/2009/04/24/health/policy/24cancer.html?partner=rss&emc=rss

picture-51

Doctor quote in cancer article nyt