U.S. breast cancer cases have dropped in women aged 50 to 69 in recent years because many women have stopped taking hormone therapy, according to a study in The New England Journal of Medicine.
A study in the New England Journal of Medicine suggests long-term use of hormone therapy causes breast cancer.
The good news: The study found that breast cancer risk in women who took hormones dropped back down to normal soon after they quit.
The bad news: In the last decade in which it was still widely used (1992--2002), long-term hormone therapy probably caused breast cancer in 200,000 women, said Dr. Rowan T. Chlebowski, a medical oncologist at the Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center in Torrance and the study's lead author.
Currently, the Food and Drug Administration recommends that women who want to take hormones only do so at the lowest dose and for the shortest possible time to relieve menopausal symptoms, such as hot flashes. Using hormones for two years or less appears to be safe for many women, and estrogen alone is generally safer than estrogen-progestin, according to a recent analysis by experts at the American Cancer Society.
Long-term hormone use, however, is a problem. Scientists who study cancer rates saw a 10 percent drop-off in new breast cancers in 2003, about a year after alarming findings from the Women's Health Initiative (WHI) study led many older women to stop taking estrogen and progestin. Only women who've had a hysterectomy can take estrogen alone; progestin is added to estrogen to reduce the risk of cancer of the lining of the uterus.
In 2003, as well as in 2004 and 2005, 20,000 fewer breast cancer cases were diagnosed in the United States than would have been expected.
In the current study, researchers went back to look women who'd taken part in the WHI study. They looked at what happened to breast cancer risk in individual women after they stopped taking Prempro, an estrogen-progestin combination. At the time, about 6 million women in the U.S. were taking Prempro; prescriptions had dropped 66 percent by early 2003.
Some experts have argued that breast cancer rates declined because fewer women were getting mammograms (so fewer cancers were being detected), and that the drop-off in cancer rates could not have happened so soon after women quit taking hormones.
But the current study showed that, in fact, it did.
Within two years of quitting, breast cancer risk for women who had been taking hormones was the same as that for women who never took them. Mammogram rates were nearly identical in both groups of women.
"It's just a substantial decline any way you cut it," said Tina Clarke, a research scientist at the Northern California Cancer Center in Fremont, who was not involved in the new study. Clarke was among those who had observed the decline in breast cancer, which dropped "like a rock" after 2002, she noted.
The findings also suggest, Clarke added, that pockets of very high rates of breast cancer seen in affluent communities, including California's Marin County and Long Island, New York, were likely related to high hormone replacement therapy use, as well as demographic factors such as late childbearing among these women. Cancer rates in Marin, she added, have dropped just as dramatically as they have elsewhere in California.
In the current report, Chlebowski and colleagues looked at two arms of the WHI study. In one, a clinical trial, 16,608 postmenopausal women had been randomly assigned to take estrogen plus progestin or a placebo. In the other, the researchers observed 16,121 women who were already on hormones and another 25,328 who weren't taking them at the study's outset.
The researchers halted the clinical trial in 2002 after long-term combination hormone therapy was associated with higher rates of breast cancer, strokes, and heart attacks. At that point many women in the observational study also quit using hormones.
In clinical trial participants, the incidence of breast cancer was at first lower in the hormone group, but then climbed steadily over the 5.6 years of the study. But breast cancer incidence started falling immediately after the women stopped taking hormones and was back to normal in about two years.
In the observational study, the hormone-taking women --who took them for about seven years, on average-- were about twice as likely to be diagnosed with breast cancer than women who weren't taking hormones. But after 2002, their risk declined and in fact was on par with that of the non-hormone-taking women within about two years.
"For longer duration therapy, this provides new evidence that the risk is higher than we previously thought," said Chlebowski. He said that a 55-year-old woman whose mother developed breast cancer at 62 would have a 2 percent chance of developing breast cancer in five years. Doubling that risk with long-term hormone use translates to a 4 percent chance of getting cancer, or 1 in 50.
"The risk is not one of those few-in-a-thousand things," he said.
Although so-called bioidentical hormones are being touted as a safe alternative to traditional hormone therapy, they are not, said Dr. Margery Gass, director of the University Hospital Menopause and Osteoporosis Center in Cincinnati. "There's absolutely no sound evidence that they are any safer or more effective," she said.
Menopause isn't a disease that needs to be treated, she said, but is in fact a natural state that even has health benefits.
Supporters say these hormones are identical to those the body makes on its own, and are thus safer than formulations like those given to Women's Health Initiative participants, which were derived from horse urine. Bioidentical hormones have gotten a big boost from Suzanne Somers' books The Sexy Years and Ageless: The Naked Truth About Bioidentical Hormones.
But these products, which are typically made in compounding pharmacies or derived from plants, have not been approved by the Food and Drug Administration, Dr. Gass points out. Women who want to use hormone therapy should stick to FDA-approved products, which are better studied and likely cheaper, said M. Sara Rosenthal, a bioethicist at the University of Kentucky in Lexington, who is interested in the ethics of endocrine replacement.
"Women who think bioidentical hormones are superior or less risky are being sold hormonal snake oil," Rosenthal said.
Source: CNNhealth.com
Hormonal therapy medicines are NOT effective against hormone-receptor-negative breast cancers.
There are several types of hormonal therapy medicines, including aromatic inhibitors, selective estrogen receptor modulators, and estrogen receptor down regulators.
Posted by: x-ray fluorescence | March 04, 2009 at 12:27 AM
Gasoline, Petroleum and the plastics made from it are the single largest cause of cancer in the world. This is a known fact, verified by thousands of studies which the oil industry counters by paying pundits to say: "Well, we just are not sure yet". Now we are sure. The TPH array in petroleum and petroleum products exists as microscopic particles which leach off of plastic materials, (ie: the plastic in water and baby bottles) and float in the air as vapor, (ie: the fumes around gas stations). These particles are absorbed into the body and broken down to a cellular level and then to a DNA level. As the DNA replicates, a constant process, these TPH materials cause the replication process to make mistakes and create genetic mutations. TPH is a very particular array of items so the "mistakes" that it causes occur as the same thing over and over. We call this repeating mistake: "cancer". Other materials in our environment cause other kinds of genetic mutations that do not manifest as onerous, or extremely negative, or obvious things. TPH manifests cancer.
The TPH chemical array has killed more Americans than every terrorist since the beginning of time.
The petrochemical bisphenol-a, or BPA, causes precancerous tumors and urinary tract problems and made babies reach puberty early.
Every gas pump has a label on it that oil and gas causes cancer and a host of lethal medical problems.
Archeologicial digs show that ancient peoples living near tar pits got cancer.
When there is an oil spill, you are not allowed on the beach because most agencies classify oil as toxic.
A study of childhook leukemia in England mapped every child with the diserase and found they all occurred in a circle, in the center of which was a gas station.
Living near a petrol station could quadruple the risk of childhood leukaemia, research suggested today.
The study in France found a link between cases of acute leukaemia among youngsters and how close they lived to a fuel station or a repair garage.
Research has already shown an association between adults' occupational exposure to benzene, a hydrocarbon derived from petrol, and leukaemia.
The latest study is published in the journal Occupational and Environmental Medicine. The French Institute of Health and Medical Research based their findings on 280 cases of childhood leukaemia and a comparison group of 285 children.
They were drawn from four hospitals in Nancy, Lille, Lyon and Paris, with almost two-thirds of the children with leukaemia aged between two and six.
The team found no clear link between the mother's occupation during pregnancy or traffic levels around where they lived and the risk of child leukaemia.
They also saw no link between leukaemia and living near manufacturers using materials such as aluminium or plastic.
But a child whose home was near a garage was four times more likely to develop leukaemia than a child whose home was not.
The risk appeared to be even greater for acute nonlymphoblastic leukaemia, which was seven times more common among children living close to a petrol station or garage. The longer a child had lived there, the higher their risk of leukaemia appeared to be.
There are 6,600 cases of leukaemia a year in Britain. Although it is the most common form of childhood cancer, it affects three times as many adults as children.
The authors admit the findings could be due to chance. "But the strength of the association and the duration of the trend are arguments for a causal association."
Alberta’s oil sands are one of the world’s biggest deposits of oil, but the cost of extracting that oil may be the health of the people living around them. High levels of toxic chemicals and carcinogens have been found in the water, soil, and fish downstream of the oil sands. The local health authority of Fort Chipewyan, Alberta comissioned the study in response to locals’ claims that the oil extraction projects upstream were damaging the health of citizens. Petrochemicals and their byproducts, such as dioxin, are known to cause an array of serious health problems, including cancers and endocrine disruption.Total petroleum hydrocarbons (TPH) is a term used to describe a large family of several hundred chemical compounds that originally come from crude oil. Crude oil is used to make petroleum products, which can contaminate the environment. Because there are so many different chemicals in crude oil and in other petroleum products, it is not practical to measure each one separately. However, it is useful to measure the total amount of TPH at a site.TPH is a mixture of chemicals, but they are all made mainly from hydrogen and carbon, called hydrocarbons. Scientists divide TPH into groups of petroleum hydrocarbons that act alike in soil or water. These groups are called petroleum hydrocarbon fractions. Each fraction contains many individual chemicals.
Some chemicals that may be found in TPH are hexane, jet fuels, mineral oils, benzene, toluene, xylenes, naphthalene, and fluorene, as well as other petroleum products and gasoline components. However, it is likely that samples of TPH will contain only some, or a mixture, of these chemicals. The International Agency for Research on Cancer (IARC) has determined that one TPH compound (benzene) is carcinogenic to humans. IARC has determined that other TPH compounds (benzo[a]pyrene and gasoline) are carcinogenic to humans.
Benzene causes leukemia. Benzene as a cause of leukemia had documented since 1928 (1 p. 7-9). In 1948, the American Petroleum Institute officially reported a link between this solvent used in many of their industries used and cases of leukemia in their workers. Their findings concluded that the only safe level of benzene exposure is no exposure at all (2).
The largest breast cancer incidents are in Marin County, California which is tied to the air, water and ecosphere of the Chevron Oil refinery right next door. New studies of microparticulation and transprocess nano components show that TPH materials can travel opposite of tides and wind via secondary carriers.
The oil industries spend tens of millions of dollars on fake pundits and disinformation to make sure the above information is never known by the public. Cure Cancer: Stop oil. It is a national security need in more ways than one.
Posted by: Cara Pots | April 04, 2009 at 02:11 PM