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【medical-news】研究表明在激素疗法降低后乳腺癌
Breast Cancer Rates Fell After Hormone Treatments Declined, Study Says
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By GINA KOLATA
Published: April 18, 2007
Breast cancer rates fell sharply in 2003, and then held steady at the lower rate in 2004, researchers are reporting today.
The findings, they say, fit with a hypothesis they advanced last December when they had data only from 2003. At that time, national data showed that breast cancer rates had fallen by nearly 15 percent in the 18 months between July 2002 and December 2003.
The most likely reason for the fall in rates, according to the investigators, led by Donald Berry of M.D. Anderson Cancer Center in Houston, was that large numbers of women stopped taking hormone therapy for menopause — and that the therapy, using a combination of estrogen and progestins, can increase the incidence of breast cancer.
Now, with the 2004 data, the researchers say the effect is less likely to be an anomaly. If rates had gone up again, they explain, their hypothesis would have been contradicted.
The analysis relied on “statistical sleuthing,” said Dr. Berry, head of the division of quantitative sciences at M.D. Anderson, and the senior author of the paper that is to be published Thursday in The New England Journal of Medicine that lays out the findings.
Over all, in 2003 and 2004, there were nearly 10 percent fewer breast cancer cases diagnosed than expected. That is the first substantial drop in breast cancer incidence in more than a quarter-century. It was seen mainly among women age 50 and older, not younger women, and almost entirely in the number of cancers that are fed by estrogen — so-called estrogen receptor positive tumors — not other types.
The hormone connection came to light because the Women’s Health Initiative, a large federal study examining the health effects of Prempro, the most popular drug prescribed for menopause, was halted in July of 2002. The drug was presumed to protect women from heart disease, but the study found that the women who took it were actually at greater risk of heart disease. In addition, among women taking Prempro, made by Wyeth Pharmaceuticals, 26 percent more new breast cancer diagnoses were seen than among women taking a placebo for comparison.
Word of these results immediately sent sales of Prempro plummeting by 50 percent, and they continued to fall slightly the next year.
The drop in breast cancer rates followed immediately.
“Those are the facts,” said Dr. Peter Ravkin, an oncologist and Dr. Berry’s colleague. “We think there is a likely connection between them.”
Even so, Dr. Ravkin said, hormone therapy did not cause most of the nation’s breast cancer cases. Some types of breast cancer do not need estrogen to grow. Others that depend on estrogen grow whether or not a woman is taking Prempro or a similar drug; they are fueled by the estrogen in a woman’s body.
Dr. Ravkin added that he thought the current guidelines — advising women to use hormone therapy for as short a time as possible for the relief of menopause symptoms — were appropriate.
Dr. Joseph Camardo, senior vice president for global medical affairs for Wyeth Pharmaceuticals, urged caution in interpreting the data. Just because one event follows another does not mean one event caused the other, he said.
“I don’t think anyone involved can say they have a specific alternative explanation, but I think other factors should be explored,” he said. For example, mammogram use or changes in diet or other drug use might be contributing, he added.
But any alternative explanation must also take into account the fact that the drop in breast cancer rates was almost entirely among women with estrogen-fed tumors, Dr. Ravkin said.
Dr. Berry says the researchers are well aware of the limitations of their analysis and never said they proved that declining hormone use led to 10 percent less breast cancer.
“Of course we’re not sure. We never are,” Dr. Berry said. “But it fits,” he said. “It’s a smoking gun.” 本人已认领该文编译，48小时后若未提交译文，请其他战友自由认领 。 抱歉!迟到了太久了!
初译字数：1157
Breast Cancer Rates Fell After Hormone Treatments Declined, Study Says
研究表明激素疗法降低后乳腺癌发病率随之降低
Published: April 18, 2007
发表时间：2007年4月18日
Breast cancer rates fell sharply in 2003, and then held steady at the lower rate in 2004, researchers are reporting today.
研究人员今天报道：2003年乳腺癌发病率大幅下降，并在2004年一直保持低发病率水平。
The findings, they say, fit with a hypothesis they advanced last December when they had data only from 2003. At that time, national data showed that breast cancer rates had fallen by nearly 15 percent in the 18 months between July 2002 and December 2003.
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作者:admin@医学,生命科学 2011-02-25 05:11
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