Saturday, March 13, 2010
The Henry J. Kaiser Family Foundation - Health Policy, Media Resources, Public Health Education & South Africa
A leader in health policy and communications, the Kaiser Family Foundation is a non-profit, private operating foundation focusing on the major health care issues facing the U.S., as well as the U.S. role in global health policy. Unlike grant-making foundations, Kaiser develops and runs its own research and communications programs, sometimes in partnership with other non-profit research organizations or major media companies.
We serve as a non-partisan source of facts, information, and analysis for policymakers, the media, the health care community, and the public. Our product is information, always provided free of charge — from the most sophisticated policy research, to basic facts and numbers, to information young people can use to improve their health or elderly people can use to understand their Medicare benefits.
Friday, March 12, 2010
Two research teams have independently decoded the entire genome of patients to find the exact genetic cause of their diseases. The approach may offer a new start in the so far disappointing effort to identify the genetic roots of major killers like heart disease, diabetes and Alzheimer's.
In the decade since the first full genetic code of a human was sequenced for some $500 million, less than a dozen genomes had been decoded, all of healthy people.
Geneticists said the new research showed it was now possible to sequence the entire genome of a patient at reasonable cost and with sufficient accuracy to be of practical use to medical researchers. One subject's genome cost just $50,000 to decode.
"We are finally about to turn the corner, and I suspect that in the next few years human genetics will finally begin to systematically deliver clinically meaningful findings," said David B. Goldstein, a Duke University geneticist who has criticized the current approach to identifying genetic causes of common diseases.
Besides identifying disease genes, one team, in Seattle, was able to make the first direct estimate of the number of mutations, or changes in DNA, that are passed on from parent to child. They calculate that of the three billion units in the human genome, 60 per generation are changed by random mutation — considerably less than previously thought.
The three diseases analyzed in the two reports, published online Wednesday, are caused by single, rare mutations in a gene.
In one case, Richard A. Gibbs of the Baylor College of Medicine sequenced the whole genome of his colleague Dr. James R. Lupski, a prominent medical geneticist who has a nerve disease, Charcot-Marie-Tooth neuropathy.
In the second, Leroy Hood and David J. Galas of the Institute for Systems Biology in Seattle have decoded the genomes of two children with two rare genetic diseases, and their parents.
More common diseases, like cancer, are thought to be caused by mutations in several genes, and finding the causes was the principal goal of the $3 billion human genome project. To that end, medical geneticists have invested heavily over the last eight years in an alluring shortcut.
But the shortcut was based on a premise that is turning out to be incorrect. Scientists thought the mutations that caused common diseases would themselves be common. So they first identified the common mutations in the human population in a $100 million project called the HapMap. Then they compared patients' genomes with those of healthy genomes. The comparisons relied on ingenious devices called SNP chips, which scan just a tiny portion of the genome. (SNP, pronounced "snip," stands for single nucleotide polymorphism.) These projects, called genome-wide association studies, each cost around $10 million or more.
The results of this costly international exercise have been disappointing. About 2,000 sites on the human genome have been statistically linked with various diseases, but in many cases the sites are not inside working genes, suggesting there may be some conceptual flaw in the statistics. And in most diseases the culprit DNA was linked to only a small portion of all the cases of the disease. It seemed that natural selection has weeded out any disease-causing mutation before it becomes common.
The finding implies that common diseases, surprisingly, are caused by rare, not common, mutations. In the last few months, researchers have begun to conclude that a new approach is needed, one based on decoding the entire genome of patients.
The new reports, though involving only single-gene diseases, suggest that the whole-genome approach can be developed into a way of exploring the roots of the common multigene diseases.
Wednesday, March 10, 2010
About 16 percent of Americans between the ages of 14 and 49 are infected with genital herpes, making it one of the most common sexually transmitted diseases, U.S. health officials said on Tuesday.
Black women had the highest rate of infection at 48 percent and women were nearly twice likely as men to be infected, according to an analysis by the U.S. Centers for Disease Control and Prevention.
About 21 percent of women were infected with genital herpes, compared to only 11.5 percent of men, while 39 percent of blacks were infected compared to about 12 percent for whites, the CDC said.
There is no cure for genital herpes, or herpes simplex virus type 2 (HSV-2), which can cause recurrent and painful genital sores and also increases the likelihood of acquiring and transmitting the AIDS virus. It is related to herpes simplex virus 1, or oral herpes, which causes cold sores.
Each year some 30 million American men undergo testing for prostate-specific antigen, an enzyme made by the prostate. Approved by the Food and Drug Administration in 1994, the P.S.A. test is the most commonly used tool for detecting prostate cancer.
The test's popularity has led to a hugely expensive public health disaster. It's an issue I am painfully familiar with — I discovered P.S.A. in 1970. As Congress searches for ways to cut costs in our health care system, a significant savings could come from changing the way the antigen is used to screen for prostate cancer.
Americans spend an enormous amount testing for prostate cancer. The annual bill for P.S.A. screening is at least $3 billion, with much of it paid for by Medicare and the Veterans Administration.
Prostate cancer may get a lot of press, but consider the numbers: American men have a 16 percent lifetime chance of receiving a diagnosis of prostate cancer, but only a 3 percent chance of dying from it. That's because the majority of prostate cancers grow slowly. In other words, men lucky enough to reach old age are much more likely to die with prostate cancer than to die of it.
Even then, the test is hardly more effective than a coin toss. As I've been trying to make clear for many years now, P.S.A. testing can't detect prostate cancer and, more important, it can't distinguish between the two types of prostate cancer — the one that will kill you and the one that won't.
Instead, the test simply reveals how much of the prostate antigen a man has in his blood. Infections, over-the-counter drugs like ibuprofen, and benign swelling of the prostate can all elevate a man's P.S.A. levels, but none of these factors signals cancer. Men with low readings might still harbor dangerous cancers, while those with high readings might be completely healthy.
In approving the procedure, the Food and Drug Administration relied heavily on a study that showed testing could detect 3.8 percent of prostate cancers, which was a better rate than the standard method, a digital rectal exam.
Still, 3.8 percent is a small number. Nevertheless, especially in the early days of screening, men with a reading over four nanograms per milliliter were sent for painful prostate biopsies. If the biopsy showed any signs of cancer, the patient was almost always pushed into surgery, intensive radiation or other damaging treatments.
The medical community is slowly turning against P.S.A. screening. Last year, The New England Journal of Medicine published results from the two largest studies of the screening procedure, one in Europe and one in the United States. The results from the American study show that over a period of 7 to 10 years, screening did not reduce the death rate in men 55 and over.
The European study showed a small decline in death rates, but also found that 48 men would need to be treated to save one life. That's 47 men who, in all likelihood, can no longer function sexually or stay out of the bathroom for long.
Numerous early screening proponents, including Thomas Stamey, a well-known Stanford University urologist, have come out against routine testing; last month, the American Cancer Society urged more caution in using the test. The American College of Preventive Medicine also concluded that there was insufficient evidence to recommend routine screening.
So why is it still used? Because drug companies continue peddling the tests and advocacy groups push "prostate cancer awareness" by encouraging men to get screened. Shamefully, the American Urological Association still recommends screening, while the National Cancer Institute is vague on the issue, stating that the evidence is unclear.
The federal panel empowered to evaluate cancer screening tests, the Preventive Services Task Force, recently recommended against P.S.A. screening for men aged 75 or older. But the group has still not made a recommendation either way for younger men.
Prostate-specific antigen testing does have a place. After treatment for prostate cancer, for instance, a rapidly rising score indicates a return of the disease. And men with a family history of prostate cancer should probably get tested regularly. If their score starts skyrocketing, it could mean cancer.
But these uses are limited. Testing should absolutely not be deployed to screen the entire population of men over the age of 50, the outcome pushed by those who stand to profit.
I never dreamed that my discovery four decades ago would lead to such a profit-driven public health disaster. The medical community must confront reality and stop the inappropriate use of P.S.A. screening. Doing so would save billions of dollars and rescue millions of men from unnecessary, debilitating treatments.
Richard J. Ablin is a research professor of immunobiology and pathology at the University of Arizona College of Medicine and the president of the Robert Benjamin Ablin Foundation for Cancer Research.
One thing I do when I can't sleep is play alphabet games. I try to list various things from A to Z: countries, rock groups, prescription drugs, movies, books, celebrities whose first and last names begin with the same letter… you get the idea. I don't mind repeating categories from one night to another. Diseases might seem to be an unlikely insomnia game category, but for some reason, it's one of my favorites. I like to combine ailments that terrified me in childhood (lockjaw) with ones that I didn't know about until I was an adult (Ebola). And there are certain ailments that are never, ever on the list. Ever.
Tuesday, March 9, 2010
For decades, advocates have fought to protect women from disfiguring breast cancer surgery, arguing that it was just as effective to remove only the cancerous tissue rather than the whole breast.
But today, a growing number of women with breast cancer are pushing surgeons in a startling new direction. Not only do they want the cancerous breast removed, but they also want the healthy breast cut off.
"I just didn't want to worry about it," explained Liliana Holtzman, 50, an art director in Ann Arbor, Mich., who had both breasts removed after a cancer diagnosis five years ago. "It was for my own peace of mind. I wanted to do everything I could."
The percentage of women asking to remove both breasts after a cancer diagnosis has more than doubled in recent years. Over all, about 6 percent of women undergoing surgery for breast cancer in 2006 opted for the procedure, formally known as contralateral prophylactic mastectomy. Among women in their 40s who underwent breast cancer surgery, one in 10 opted to have both breasts removed, according to a University of Minnesota study presented last week in St. Louis at the annual meeting of the Society of Surgical Oncology.
Surprisingly, the practice is also more popular among women with the earliest, most curable forms of cancer. Among women who had surgery for ductal carcinoma in situ, sometimes called Stage 0 cancer or precancer, the rate of double mastectomy rose to 5.2 percent in 2005, from 2.1 percent in 1998, according to a 2009 study in The Journal of Clinical Oncology.
Women with a known genetic risk for breast cancer can lower the chances of developing it by having both breasts removed before cancer appears. But for most women given a diagnosis of breast cancer, cutting off a healthy breast does not improve the odds of survival.
A few years later, when I was a physician and after I'd done an additional Ph.D. on hospital safety, I met Sorrel King, whose 18-month-old daughter, Josie, had died at Hopkins from infection and dehydration after a catheter insertion.
Dr. Peter J. Pronovost, 45, is medical director of the Quality and Safety Research Group at Johns Hopkins Hospital in Baltimore, which means he leads that institution's quest for safer ways to care for its patients. He also travels the country, advising hospitals on innovative safety measures. The Hudson Street Press has just released his book, "Safe Patients, Smart Hospitals: How One Doctor's Checklist Can Help Us Change Health Care from the Inside Out," written with Eric Vohr.