VOA英语2010年-Estrogen Therapy Reduces Breast Cancer Risk

A new analysis of data from a study of post-menopausal women is challenging existing guidelines on hormone¹ therapy. The researchers say women taking estrogen alone are at a significantly lower risk of breast cancer, and do not show an increased risk of blood clots² or stroke, as reported in an earlier study.

Synthetic³ estrogen was first developed around 80 years ago and has been used to replace the natural hormone that women no longer produce after menopause. It later became routine for doctors to prescribe estrogen - alone or in combination with progesterone - to ease menopausal symptoms.

Then, in 2002, U.S. officials added estrogen to a list of substances "known" or "reasonably anticipated" to cause cancer.

That finding came from a huge U.S. research study called the Women's Health Initiative, which also challenged previous studies that suggested hormone treatment protected against heart disease and stroke.

Dr. Joseph Ragaz of Canada's University of British Columbia and colleagues have sifted⁴ through data from the Women's Health Initiative and concluded that estrogen therapy not only does not cause breast cancer, it actually may protect many women from the disease.

"Estrogen alone can be recommended for a majority of women in menopause to prevent quality of life deterioration⁵, but also to reduce breast cancer," Ragaz says.

The researchers found a modest reduction for women who may already be at risk for breast cancer, such as those with a family history of the disease. But for the majority of women who don't have the risk factors, Ragaz says the benefit of the estrogen therapy is very substantial.

"Those women without underlying⁶ risk benefit significantly more - the figures are up to 30 to 40 percent reduction of breast cancer risks. In our final recommendation we will have to say that one shoe is not for everybody; we still have to skillfully identify the low-risk and high-risk [patients]."

Previous analysis of data from the Women's Health Initiative found a slightly lower risk of breast cancer among women taking estrogen alone, but the reduction wasn't statistically⁷ significant.

Ragaz says natural estrogen produced by a woman appears to promote cancer, but the synthetic variety used in hormone therapy seems to protect breast tissue from cancer. He admits it is unclear why this would be, and says it is not the subject of his current research.

Ragaz and his colleagues also found that women who begin estrogen therapy before age 60 show reduced risk of heart disease, colon⁸ cancer, and bone fracture. They did not find an increased risk of stroke or blood clots, which was found previously⁹ in a group that included women who began taking hormones¹⁰ at all ages.

However, he also said that his analysis confirms earlier findings that hormone therapy that combines estrogen with progesterone does significantly increase the risk of breast cancer.

Joseph Ragaz of the University of British Columbia presented his findings in Texas at the San Antonio Breast Cancer Symposium¹¹, co-sponsored by the American Association for Cancer Research and academic institutions.

1 hormone   

n.荷尔蒙，激素，内分泌

参考例句：

• Hormone implants are used as growth boosters.激素植入物被用作生长辅助剂。
• This hormone interacts closely with other hormones in the body.这种荷尔蒙与体內其他荷尔蒙紧密地相互作用。

2 clots   

n.凝块( clot的名词复数 )；血块；蠢人；傻瓜v.凝固( clot的第三人称单数 )

参考例句：

• When you cut yourself, blood clots and forms a scab. 你割破了，血会凝固、结痂。 来自《简明英汉词典》
• Milk clots when it turns sour. 奶变酸就凝块。 来自《现代英汉综合大词典》

3 synthetic   

adj.合成的，人工的；综合的；n.人工制品

参考例句：

• We felt the salesman's synthetic friendliness.我们感觉到那位销售员的虚情假意。
• It's a synthetic diamond.这是人造钻石。

4 sifted   

v.筛( sift的过去式和过去分词 )；筛滤；细查；详审

参考例句：

• She sifted through her papers to find the lost letter. 她仔细在文件中寻找那封丢失的信。 来自《简明英汉词典》
• She sifted thistles through her thistle-sifter. 她用蓟筛筛蓟。 来自《简明英汉词典》

5 deterioration   

n.退化；恶化；变坏

参考例句：

• Mental and physical deterioration both occur naturally with age. 随着年龄的增长，心智和体力自然衰退。
• The car's bodywork was already showing signs of deterioration. 这辆车的车身已经显示出了劣化迹象。

6 underlying   

adj.在下面的，含蓄的，潜在的

参考例句：

• The underlying theme of the novel is very serious.小说隐含的主题是十分严肃的。
• This word has its underlying meaning.这个单词有它潜在的含义。

7 statistically   

ad.根据统计数据来看，从统计学的观点来看

参考例句：

• The sample of building permits is larger and therefore, statistically satisfying. 建筑许可数的样本比较大，所以统计数据更令人满意。
• The results of each test would have to be statistically independent. 每次试验的结果在统计上必须是独立的。

8 colon   

n.冒号，结肠，直肠

参考例句：

• Here,too,the colon must be followed by a dash.这里也是一样，应当在冒号后加破折号。
• The colon is the locus of a large concentration of bacteria.结肠是大浓度的细菌所在地。

9 previously   

adv.以前，先前（地）

参考例句：

• The bicycle tyre blew out at a previously damaged point.自行车胎在以前损坏过的地方又爆开了。
• Let me digress for a moment and explain what had happened previously.让我岔开一会儿，解释原先发生了什么。

10 hormones   

n. 荷尔蒙，激素 名词hormone的复数形式

参考例句：

• This hormone interacts closely with other hormones in the body. 这种荷尔蒙与体內其他荷尔蒙紧密地相互作用。
• The adrenals produce a large per cent of a man's sex hormones. 肾上腺分泌人体的大部分性激素。

11 symposium   

n.讨论会，专题报告会；专题论文集

参考例句：

• What have you learned from the symposium?你参加了这次科学讨论会有什么体会？
• The specialists and scholars present at the symposium come from all corners of the country.出席研讨会的专家学者们来自全国各地。