Thursday, July 26, 2007

New Study Reaffirms HRT Link to Breast Cancer Rate Decline

TUESDAY, July 24 (HealthDay News) -- Scientists have once again linked a drop in breast cancer rates from 2003 to 2004 to a parallel decrease in women's use of hormone therapy beginning in 2002.
The decline in breast cancer rates persisted even though mammography screening rates remained stable, said researchers at Kaiser Permanente, reporting in the August issue of the Journal of the National Cancer Institute.
"The message is pretty straightforward," said study lead author Dr. Andrew Glass, senior investigator at the Kaiser Permanente Center for Health Research in Portland, Ore. "If you need to take hormone therapy to block menopausal symptoms, do it for the shortest duration and the lowest dose."
"We now have a second observation that when we discontinue or decrease hormone therapy, we have a very significant drop in breast cancer incidence," added Dr. Jay Brooks, chairman of hematology/oncology at Ochsner Health System in Baton Rouge, La. "This is another piece of information that I think women should use in determining whether or not they want to take hormone therapy. To me, it shows that combination therapy [estrogen plus progestin] does increase the incidence of breast cancer. Women need to take this into consideration."
Last December, a different set of researchers reported a precipitous drop in the incidence of breast cancer in 2003 and suggested that the downward trend was the result of millions of women discontinuing use of hormone replacement therapy.
The decline in the number of U.S. women taking hormone replacement therapy came after publication of the results of the landmark Women's Health Initiative (WHI) trial in 2002. That study, involving 16,608 participants, was halted after researchers found elevated health risks among HRT users, most notably for breast cancer and stroke.
Since then, a debate has continued over the utility and safety of hormone therapy, with health officials advising women to take HRT only when needed and for as short a period as possible.
The authors of the new study reviewed the medical histories of 7,386 women diagnosed with invasive breast cancer and treated at Kaiser Permanente Northwest between 1980 and 2006. The records were available through Kaiser Permanente's computerized database, which includes a tumor registry and clinical, pathology, radiology and pharmacy data systems.
From the early 1980s to the early 1990s, breast cancer rates rose 26 percent, then an additional 15 percent through 2001. From 2003 to 2006, rates dropped by 18 percent.
The 26 percent increase paralleled increases in the rates of mammograms as well as increases in the use of hormone therapy, especially combination therapy, the researchers said.
The 15 percent increase -- from 1992 to 2002 -- echoed a continued rise in the use of hormone therapy, although mammogram rates remained stable from 1991 rates.
The drop in breast cancer rates starting in 2003 coincided with a 75 percent drop in hormone therapy rates, although mammography rates remained the same.
"When HRT went down, breast cancer rates went down and mammography rates remained the same," Glass said. "This was an important finding, because others had suggested maybe the drop in breast cancer rates was because mammograms had gone down, but it didn't happen in the Kaiser numbers. The only thing we can figure out is, it's probably related to HRT, that fluctuations in HRT are the most likely explanation for fluctuations in breast cancer rates."
The increase in breast cancer rates occurred primarily in women over the age of 45 who had estrogen receptor-positive breast cancer.
According to Glass, this study is the first to document all these different factors -- mammography, hormone therapy, breast cancer and estrogen-receptor status -- in one study.
But one expert found the study's conclusions lacking.
"This is an interesting look at the picture but really is not evidence-based medicine," said Dr. Lila Nachtigall, director of the women's wellness program at New York University Medical Center and professor of obstetrics and gynecology at New York University School of Medicine. The study did not correlate individual cases of breast cancer with hormone use, therefore issues of causality cannot be decided, she added.

Saturday, June 30, 2007

Glucosamine Trials Show Little Benefit Against Arthritis

FRIDAY, June 29 (HealthDay News) -- Although millions of arthritis sufferers buy glucosamine supplements to ease their joint pain, there's still no convincing proof the product works, according to a major new analysis.
In fact, the results of 15 trials of over-the-counter glucosamine vary so widely that industry bias may be a factor influencing the more positive outcomes, concludes a team writing in the July issue of Arthritis & Rheumatism.
"There's a big difference between trials, much more than you would expect by chance," explained lead investigator Dr. Steven Vlad, a fellow in rheumatology at Boston University Medical Center.
But an editorialist in the journal refutes those claims.
Dr. Jean-Yves Reginster, of the World Health Organization's Collaborating Center for Public Health Aspects of Rheumatic Disease, in Liege, Belgium, counters that industry trials are typically more stringent than independent academic research. He also believes that Vlad's group included trials in their analysis that were very unalike in terms of timeframes and methodology, confusing the results.
So, the years-long scientific debate on glucosamine continues. The popular supplement did take a major hit earlier this year, when a major U.S. study published in the New England Journal of Medicine found glucosamine hydrochloride to be of little help for knee osteoarthritis.
But Vlad also knew that other studies had found a real benefit to regular glucosamine use. Why the differences between trials?
To find out, he and his team combed through the available literature and selected 15 double-blind, placebo-controlled, randomized clinical trials that looked at the use of glucosamine for more than four weeks to help fight hip or knee osteoarthritis pain.
Trials involved either of the two major glucosamine preparations: glucosamine hydrochloride or glucosamine sulfate. Each delivers glucosamine bound to a different chemical salt.
First of all, the team determined one of the preparations to be useless.
"I think we have shown pretty conclusively that glucosamine hydrochloride doesn't work," Vlad said. "The data there is all consistent, it goes together -- there's just no evidence that it works."
But that wasn't the story with the other preparation, glucosamine sulfate.
In that case, results varied widely between the randomized trials. However, that variance went far beyond random chance. In fact, according to Vlad, the spread in results among various trials was four times that which would be normally expected.
No particular feature of the studies' design helped explain this disparity, except for differences among trials in what's known as "allocation concealment" -- the fact that some trials were more lax than others at concealing from the researchers involved which patients would get the drug and which would get a placebo.
One factor did appear to play a role in the variance between the glucosamine sulfate trial results: industry involvement.
"It's really hard to know just how big a factor that is," Vlad said, "whether it's manufacturing the whole effect or just exaggerating an effect that's there." He also stressed that, "If there is a bias from industry, I doubt very much that it is intentional. People want to sell their product, but I think that they rarely go into a study with the intention of twisting the results."
But Reginster, in his editorial, believes Vlad's own analysis is flawed. He agreed with the Boston group that industry involvement can, and often does, influence trial results. But he also notes that many of the industry studies included in the Boston analysis had to pass muster with the European League Against Rheumatism, the expert body which vouched for many of the trials' high quality.
That's important, he said, because -- unlike in the United States -- glucosamine sulfate is approved for sale as a prescription drug by regulatory agencies in Europe. To gain approval, industry-funded trials must conform to regulatory oversight and are often better designed than independent studies, he noted.
But Vlad doesn't buy that argument. "I would agree with [Reginster] that, in general, drug manufacturers do produce better trials," he said. "But I also believe it is too simplistic to say that academic researchers aren't as good at weeding out confounding factors and things that would influence the results. They can produce trials that are every bit as good."
Another expert weighed in on the issue.
"I have worked on both sides [industry and independent]," said Malachy McHugh, director of research at the Nicholas Institute of Sports Medicine and Athletic Trauma, at Lenox Hill Hospital, in New York City. He said one issue at play is the dire lack of quality independent studies.
"In the nutritional supplement area, the bigger problem is that there is a disincentive for companies to have their products tested," he said. "If they can convince people that their product works, why run the risk of proving otherwise? There are also many negative studies that never see the light of day."
Reginster lobbed another major criticism at the Vlad study. In his opinion, the Boston group mixed together trials with widely varying timeframes (four-week studies and three-year trials), glucosamine delivered in both injections and pills, and studies of greatly differing quality. This type of heterogeneity was bound to lead to variety in results, he wrote.
Vlad agreed that his team's analysis did cast a wide net, but he said that's the way meta-analyses are typically performed. "You try and capture all the trials that may be relevant to your question," he said. Select too few trials, he said, and you lose statistical power.
The system is "never going to be perfect," Vlad said.
He stressed that the new analysis does not close the book on glucosamine. And given the supplement's good safety profile, patients who really believe they are reaping a benefit from the glucosamine sulfate should feel free to continue to take it.
Vlad and McHugh remain dubious, however, that the pricey supplement does ease osteoarthritis pain.
"From my perspective," McHugh said, "the New England Journal of Medicine paper provides the most objective take on the efficacy. The bottom line is that there is limited efficacy."
In a related study in the same issue of the journal, U.S. researchers surveyed more than 6,000 people with rheumatoid arthritis and found that most are reluctant to switch to a new medication as long as their condition does not worsen.
The team from the National Data Bank for Rheumatic Diseases in Wichita, Kan., found three-quarters of respondents were happy with their current medications, and almost two-thirds (64 percent) said they wouldn't try a new drug unless their symptoms deteriorated. The findings may explain why many patients hold off trying promising new medications, the researchers said.

Friday, June 22, 2007

Study to Assess Hormone Therapy Before Menopause

FRIDAY, June 22 (HealthDay News) -- Researchers at eight locations across the United States plan to examine the safety and effectiveness of estrogen therapy during perimenopause, the few years just prior to menopause.
The KEEPS (Kronos Early Estrogen Prevention Study), led by researchers at the University of Wisconsin (UW) School of Medicine and Public Health, will evaluate the effect that four years of estrogen therapy has on mood and cognition in 720 healthy perimenopausal women.
"There has been a tremendous amount of important and valuable research done on the positive and negative health effects of therapy using estrogen in menopausal women," study leader Sanjay Asthana, head of the UW Section of Geriatrics and Gerontology and director of the Geriatric Research, Education and Clinical Center, said in a prepared statement.
"It is my belief that this study will go a long way in helping us understand the complexity of estrogen and related hormones in humans. It is critical that we continue to systematically address all of the clinical issues concerning estrogen treatment and its effects on diseases like Alzheimer's," Asthana said.
The $3.4 million study will be funded by the U.S. National Institutes of Health.
Among its objectives, KEEPS will compare an arm patch that delivers a natural, human form of estrogen to the commonly used oral form of estrogen synthesized from animal sources.
Other goals include determining the best way to counteract the adverse effects of estrogen on the lining of the uterus and investigating which hormone therapy best mimics the menstrual cycle.

Sunday, June 17, 2007

Girls Who Like Dad Favor Partners Who Look Like Him

The study, published in the July issue of the journal Evolution and Human Behavior by British and Polish psychologists, also found that women who had a negative/less positive childhood relationship with their father weren't attracted to men who looked like their father.
The researchers had 49 Polish women (eldest daughters) look at pictures of 15 faces and choose the one they found most attractive. Their selections were compared to their fathers' faces. The women were also asked to rate their childhood relationship with their father.
The findings offer new insight into how people select partners and the effect that parents have on the process, the researchers said. Until recently, it was believed that this parental influence was a passive process. But this study adds to growing evidence that it's actually an active process.
The results of this study "show for certain that the quality of a daughter's relationship with her father has an impact on whom she finds attractive. It shows our human brains don't simply build prototypes of the ideal face based on those we see around us, rather they build them based on those to whom we have a strongly positive relationship. We can now say that daughters who have very positive childhood relationships with their fathers choose men with similar facial characteristics to their fathers," study author Dr. Lynda Boothroyd of Durham University said in a prepared statement

Friday, June 8, 2007

Vitamin D Cuts Cancer Risk: Study

FRIDAY, June 8 (HealthDay News) -- Boosting your vitamin D intake can dramatically reduce your risk of breast and other cancers, a new study found.
The research adds to growing evidence that vitamin D can help protect against many forms of cancer as well as other diseases, Creighton University researchers said.
But an American Cancer Society spokeswoman urged caution in interpreting the findings, saying it was premature to recommend taking vitamins to reduce cancer risk.
Joan Lappe, a Creighton University professor of medicine and nursing and lead author of the study, said, "What we can say from our study is that 1,100 international units (IUs) a day of vitamin D definitely decreased the incidence of cancer."
That amount of the vitamin is nearly triple the recommended intake for the age group studied -- women who were 55 and older when the four-year study started.
Lappe's team followed 1,179 study participants who were all postmenopausal and lived in rural Nebraska. The women were free of known cancers for the 10 years before entering the study. They were assigned to one of three groups and followed for four years.
One group took 1,400 to 1,500 milligrams of supplementary calcium a day, another group took that same amount of calcium plus 1,100 IUs of vitamin D daily, while the third group took placebo pills every day.
After four years, those in the combination vitamin D and calcium group had a 60 percent lower risk of developing cancer, compared to the placebo group. The calcium-only group had a 47 percent reduced risk.
Then the researchers eliminated data from the first year of the study, figuring some women may have entered the study with cancer that had not yet been diagnosed. The results were more dramatic, Lappe said.
When the researchers looked at results from just the last three years of the trial, they found the combination calcium-and-vitamin D group had a 77 percent reduced risk of cancers, compared to the placebo group. The risk for the calcium-only group was essentially unchanged.
In all, a total of 50 women got non-skin cancers during the study, with breast cancer the most common. The other cancers included lung and colon tumors.
The findings are published in the June edition of the American Journal of Clinical Nutrition.
In May, Harvard Medical School researchers reported in the Archives of Internal Medicine that high intakes of vitamin D and calcium cut the risk of breast cancer by nearly one-third in premenopausal women, but not women past menopause.
Dr. Michael Holick, professor of medicine, physiology and biophysics at the Boston University School of Medicine and a long-time vitamin D researcher, said the Lappe study adds to growing evidence of the health and disease-fighting effects of vitamin D.
"It's very clear the data are significant," he said of the Lappe study.
Vitamin D is thought to act through the immune system to help prevent the formation of abnormal cells, Lappe said.
To date, both Lappe and Holick said, high intake of vitamin D has been found to reduce the risk of many forms of cancer as well as type 1 diabetes, multiple sclerosis, rheumatoid arthritis and high blood pressure.
Both researchers think the current recommendations for daily vitamin D intake should be boosted. The U.S. Institute of Medicine, which makes recommendations on vitamin and mineral requirements, considers 200 IUs of vitamin D adequate for children and adults up to age 50; 400 IUs adequate for adults 51 to 70, and 600 for those 71 and older. The levels aren't Recommended Dietary Allowances, or RDAs, because the institute doesn't think there's enough evidence to establish an RDA for vitamin D.
"I think it's safe to say the current recommendations are much too low," Lappe said, adding that postmenopausal women should "probably be taking 1,100 IUs a day."
She recommends vitamin D3 supplements, the type used in the study, over D2, because D3 is more active, she said.
But Marji McCullough, strategic director of nutritional epidemiology for the American Cancer Society, who is familiar with the new study and other similar research, said in a prepared statement that the society doesn't currently recommend taking vitamin or mineral supplements to reduce cancer risk. But it has joined other health organization to weigh the evidence of vitamin D, and a joint panel recommends supplementation and small amounts of ultraviolet exposure "as the best way to achieve proper vitamin D status."
While she called the new study "intriguing,'' she said the number of participants was small and the research needs to be replicated before firmer conclusions can be drawn.
Discuss vitamin D intake with your doctor. And be aware that the Institute of Medicine has declared that 2,000 IUs is the upper tolerable, or safe, level for most people. For babies up to 1 year old, the limit is 1,000 IUs, McCullough said.
Vitamin D, which is important for strong bones, is found in salmon and other fish, and fortified milk and fortified cereals, among other foods.
Supplements aren't the only potential way to fight disease. In the same issue of the journal, another report found that a high intake of whole grain foods reduced the risk of atherosclerosis, or hardening of the blood vessels, which can lead to heart disease.
U.S. researchers tracked 1,178 men and women, from 40 to 69 years old at the start of the study, and found that eating more whole grains was associated with a lower risk of atherosclerosis.