October 2010 Archives
WASHINGTON--Menopausal women taking combined hormone therapy have an elevated risk of being diagnosed with a more advanced stage of breast cancer and dying from it, according to a new US study.
Researchers conducted a new analysis of a landmark, federally funded clinical trial known as the Women's Health Initiative (WHI), which was halted in 2002 after data suggested women who took a combination of estrogen and progestin hormones faced a higher risk of breast cancer.
The study, published in this week's edition of the Journal of the American Medical Association, also found that women who previously used hormone therapy and discontinued it after the WHI was terminated still faced a slightly higher breast cancer mortality rate than women not taking hormones.
For their analysis, Rowan Chlebowski of the Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center and colleagues observed 16,608 postmenopausal women ages 50 to 79 years with no prior hysterectomy from 40 US clinical centers.
Their follow-up of about 11 years of WHI participants found that 385 women receiving hormones for an average of 5.6 years, or 0.42 percent, developed invasive breast cancer, compared with 293 women who received a placebo, or 0.34 percent.
A significantly larger fraction of the women in the hormone therapy group -- 81, or 23.7 percent -- were diagnosed after their breast cancer had spread to lymph nodes. In the placebo group, only 43 women, or 16.2 percent, were diagnosed at that stages.
Twenty-five of the women who received the hormone therapy died from breast cancer, compared to 12 deaths among those who received a placebo. That translated to one to two extra deaths from breast cancer each year for every 10,000 women who used hormone therapy rather than a placebo.
Researchers noted that in the WHI trial, unlike most observational studies, combined hormone therapy both increased the risk of breast cancer and interfered with breast cancer detection, hindering the detection of breast cancer and thus leading to diagnoses at more advanced stages.
"Now, with longer follow-up results available, there remains a cumulative, statistically significant increase in breast cancers in the combined hormone therapy group, and the cancers more commonly had lymph node involvement," the researchers said.
"The observed adverse influence on breast cancer mortality of combined hormone therapy can reasonably be explained by the influence on breast cancer incidence and stage."
They noted that the incidence of breast cancer substantially decreased in the United States after the WHI trial's results were initially reported eight years ago, which was attributed to a marked decrease in postmenopausal hormone therapy use.
"The adverse influence of estrogen plus progestin on breast cancer mortality suggests that a future reduction in breast cancer mortality in the United States may be anticipated as well," the researchers added.
In an accompanying editorial, Peter Bach of Memorial Sloan-Kettering Cancer Center in New York said "the available data dictate caution in the current approach to use of hormone therapy," namely because physicians are "ill-equipped" to anticipate its effects on long-term health.
"Clinicians who prescribe brief courses of hormone therapy for relief of menopausal symptoms should be aware that this approach has not been proven in rigorous clinical trials and that the downstream negative consequences for their patients are of uncertain magnitude," Bach added.
SYDNEY--Coral reefs in Southeast Asia and the Indian Ocean are dying from the worst bleaching effect in more than a decade, Australian marine scientists said Tuesday.
The bleaching, triggered by a large pool of warm water which swept into the Indian Ocean in May, has caused corals from Indonesia to the Seychelles to whiten and die, Australia's Centre of Excellence for Coral Reef Studies said.
Reefs in the Philippines, Sri Lanka, Myanmar, Thailand, Malaysia and Singapore were also affected by the phenomenon under which sea temperatures rose by several degrees Celsius in Indonesia, researcher Andrew Baird said.
"It is certainly the worst coral die-off we have seen since 1998. It may prove to be the worst such event known to science," he said.
Baird, a fellow at James Cook University, said the magnitude of the event was so large, and the ocean temperatures in some places raised so much higher than normal, that it was "almost certainly a consequence of global warming".
He said for six to eight weeks from mid-May the temperatures were high enough to cause bleaching of the corals in Indonesia's Aceh, the area worst hit by the event.
"You jump into the water and you are just surrounded by white and dead corals," he said. "It is an extraordinary sight. The locals tell us they have seen nothing like this before."
Baird said the massive die-off was expected to compare in scale and magnitude to the damage caused in 1998, when warmer water bleached reefs globally and about 16 percent were seriously degraded.
"This is the second big global bleaching event that we have documented," he told AFP.
"The scale of the event is so large that it is going to take reefs a long time to recover," he added.
The bleaching is caused by the warm water sweeping over the reefs, shocking the corals and causing them to shed the algae which nourish them. If corals fail to regain their algae, they starve to death.
Baird said it was too early to say whether Australia's Great Barrier Reef, a major tourist attraction swarming with marine life, would be damaged but that he expected bleaching to affect reefs in the Andaman Sea and central Pacific.
"Once the reef dies you lose both live coral cover, which lots of fish need... but then everything that feeds on them will disappear as well," he said, adding that he expected some fish species to decline within a year.
He said in Aceh alone, an area with some unique marine creatures, there would be a loss of biodiversity.
"There's a very good chance that there will be some local extinctions both of endemic fish and of coral," he said.
Baird said the reefs could take years to recover, heavily impacting fishing and tourism in the region and could become a security issue.
"It's one of the reasons that countries like Australia need to act quickly and decisively on climate," he said.
Scientists say corals are vital to marine life because they provide habitats for a vast variety of creatures and absorb large levels of poisonous carbon dioxide.
WASHINGTON--Persons addicted to heroin or prescription pain killers can get help kicking their habit by using an implanted device under the skin that delivers small doses of medication, researchers reported Tuesday.
A study led by Walter Ling of the University of California-Los Angeles found that persons receiving the implants of buprenorphine had more success in ending their dependence on opioids, which include heroin and prescription pain medications, with fewer symptoms of withdrawal.
"Those who received buprenorphine implants also had fewer clinician-rated and patient-rated withdrawal symptoms, had lower patient ratings of craving and experienced a greater change... on the clinician global ratings of improvement than those who received placebo implants," the researchers wrote in the Journal of the American Medical Association.
Ling and his colleagues conducted a study of 163 adults diagnosed with opioid dependence at 18 locations in the United States between April 2007 and June 2008.
Of the group, 108 received buprenorphine implants and 55 got placebo implants. The implants were placed below the skin in the inner side of the non-dominant arm.
The implants, which gradually released 80 milligrams of buprenorphine, were removed after six months, as were the placebos.
Patients with buprenorphine implants tested negative for illicit drugs an average of 40.4 percent of the time compared to 28.3 percent for the placebo group. Additionally, 65.7 percent of patients in the buprenorphine implant group remained in the study for the full 24-week study period compared to 30.9 percent of patients in the placebo group.
The medication has previously been tried in treating addiction by administering the drug under the tongue, but researchers found that patients failed to rigorously follow the dosing schedule.
Patrick O'Connor of the Yale University School of Medicine said in an accompanying editorial that if the latest research is confirmed it "would represent a major advance in the substantial and continued progress that has occurred in the treatment of opioid dependence since methadone maintenance began in the 1960s."