Hormone Therapy Worsens Breast Cancer, Study Finds


Published: October 19, 2010
Hormone treatment after menopause, already known to increase the risk of


breast cancer, also makes it more likely that the cancer will be advanced and deadly, researchers are reporting.
The treatment studied was the most commonly prescribed hormone replacement pill, Prempro, which contains estrogens from horse urine and a synthetic relative of the hormone progesterone.




In recent years women have been urged to minimize hormone use, and the new findings lend that advice even more weight, according to the first author of an article published this week in The Journal of the American Medical Association.



Many doctors assume that women can safely take hormones for four or five years for menopause symptoms like hot flashes and night sweats, said Dr. Rowan T. Chlebowski, the first author and an oncologist who treats breast cancer patients at the Harbor-UCLA Medical Center in Torrance, Calif.

“I don’t think you can say that now,” he said. “I know some people have to take it because they can’t function, but the message now is that you really should try to stop after a year or two.”

Dr. Chlebowski said it was not known whether there is any length of time for which these hormones can be taken without increasing breast cancer risk.

The new information comes from the continuing follow-up of 12,788 women who were in the Women’s Health Initiative, a major federally financed study that compared women taking hormones with a group taking placebos.
The study was halted in 2002, three years ahead of schedule, because researchers found that the hormones were causing small but significant increases in the risk of breast cancer, heart disease, strokes and blood clots in the lungs.

The 2002 study had a huge impact. Before it came out, there was a widespread belief that hormones would reduce women’s risk of heart disease and generally keep them youthful, sexy and healthy. For many doctors and patients, the study shattered that faith.

Six million American women had been taking hormones, but the number quickly fell by about half. The breast cancer rate also began to decrease soon after, and many researchers attribute the decrease to the drop in hormone use.

The new report increases the average follow-up time to 11 years from the original 5.6 years. It is the first report from the Women’s Health Initiative that includes death rates from breast cancer related to hormone use.

The researchers found small but significant increases in several harmful effects in women who took the hormones. As the study previously showed, women taking hormones are more likely to develop invasive breast cancer.
Their rate of the disease was 0.42 percent per year, compared with 0.34 percent per year in the placebo group.

Among women with breast cancer, those who took hormones were more likely to have cancerous lymph nodes, a sign of more advanced disease — 23.7 percent, versus 16.2 percent in the placebo group.

More women who took hormones died from breast cancer — 0.03 percent per year, versus 0.01 percent per year in the placebo group. That translates to 2.6 deaths per 10,000 women per year among those taking hormones, twice as many as the 1.3 deaths per 10,000 in the placebo group.

Among women who had breast cancer, those who took hormones also had a higher death rate from other causes — 0.05 percent per year, versus 0.03 percent per year. In other words, there were 5.3 versus 3.4 deaths per 10,000 women per year — 1.9 extra deaths in hormone users.

It is not known for sure why the women taking hormones had more advanced tumors. But previous research has found that hormone treatment can cause delays in diagnosis by increasing breast density, making tumors harder to see on mammograms.

The more advanced state of the tumors in women taking hormones may help explain their increased death rate from breast cancer. Dr. Chlebowski said that in theory, the hormones may also help breast cancer and other cancers to grow and spread — which makes them more deadly — by stimulating the formation of blood vessels that feed tumors. He said that a report last year from the Women’s Health Initiative also found
that although hormone treatment did not increase women’s rate of lung cancer, hormone use was linked to a higher death rate among women who had the cancer.

Another author of the new study, Dr. JoAnn E. Manson, a professor of medicine at Harvard Medical School and Brigham and Women’s Hospital, said women should not take the hormones at all unless they really needthem, for moderate to severe symptoms like hot flashes and night sweats that disrupt sleep and really ruin their quality of life.

“It would be wonderful if there were effective options for women with moderate to severe hot flashes and night sweats that provided quality-of-life benefits without risks,” Dr. Manson said.

At the same time, she said, the new information should not necessarily alarm women who have taken the hormones, because the new report found only 1 to 2 additional breast cancer deaths per 10,000 women per year among those taking hormones.

Dr. Manson said it was the women who took hormones the longest who had the real increase in risk.

“The data suggest it is cumulative long-term use,” Dr. Manson said.
“Women should avoid long-term use. I think that’s the bottom line.”

She said that women who want treatment should take the lowest possible dose that eases their symptoms.

Noting that many women are taking other hormone formulations in hope of avoiding Prempro’s risks, Dr. Manson said little was known about the drugs and more research was urgently needed.

“We really need to know what the health effects are,” she said.

She said more research was also needed to find out whether women who took hormones early in menopause had the same risks as women who started the drugs later.

An editorial accompanying the journal article said that the researchers had probably underestimated the increase in deaths from breast cancer due to hormone therapy, and that “with longer follow-up, the deleterious effect will appear larger,” even though the women are no longer taking the drugs.

The editorial writer, Dr. Peter B. Bach, a physician at Memorial
Sloan-Kettering Cancer Center in New York, said that although the increase in cancer in the study might seem small, it becomes large when multiplied out over the population. He also questioned the advice being given to women, to consult their doctors about risks and benefits, and to take the lowest possible doses of the hormones for the shortest possible time. Like Dr. Chlebowski, he said there was no data to determine whether there is any safe interval.

“The fallback is that doctors and patients should be deciding this on a one-to-one basis, weighing risks and benefits,” Dr. Bach said in an interview. “How do you do that when you don’t know what the risks are?
It’s a data vacuum. You can’t counsel your way through a clinical
decision when you don’t have information.”

He added, “If you care about preventing this disease and keeping women from suffering and dying from it, then it’s hard to look at these drugs and not have serious concerns about them being used, even for what are intended to be relatively short periods of time.”




Not only are these drugs bad for women they’re extremely bad for the horses that are kept in wretched conditions for months at a time.


To produce the mare’s urine for collection a mare must be pregnant.  She is then kept on the pee line during her pregnancy.  These mares are kept in standing stalls with no ability to move freely.  They can go forward a step or back a step and if really lucky, get to lie down once in a while.



Once they can no longer “perform” they are cast aside, usually dumped at auctions to go for meat.

The babies that they produce are, for the most part, “unwanted” by the farmers.   They too can end up at auction to be sold not only for meat but also for their hides which are marketed as “pony skins”.

The number of these Premarin farms has mercifully declined over the past few years as doctors and their patients realize the hazards of these drugs, however, a few farms still exist in Canada.


Sadly, though, as production winds down here in North America, Pfizer, the big pharma giant that owns Wyeth the maker of Premarin, is ramping up promotion of these drugs in Asia and Europe.  To facilitate production they will, no doubt, start up massive farms in these places where thousands more horses will be at peril.


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