Tamoxifen has reduced breast cancer rates 'by a third'

Tamoxifen is a well-established and effective treatment for certain breast cancers, but  evidence of its very long-term preventive benefits," says lead author Prof. Jack Cuzick, head of the Centre for Cancer Prevention at Queen Mary University of London, UK.

"The preventive effect of tamoxifen is highly significant with a reduction in breast cancer rates of around a third," he adds, "and this impact has remained strong and unabated for 20 years."

The estimated risk of developing breast cancer after 20 years of follow-up was found to be 8% among the tamoxifen group, compared with 12% in the placebo group.

The new analysis expanded upon the International Breast Cancer Intervention Study (IBIS-I), which weighed the long-term risks and benefits of taking tamoxifen to prevent breast cancer in women considered to be at high risk.

The IBIS-I participants were 7,154 pre- and post-menopausal women aged between 35 and 70 - most of them had a family history of breast cancer.

In IBIS-I, the women were randomized to receive either 20 mg of tamoxifen or a placebo every day for 5 years. The health of all participants was monitored after treatment was completed, with an average follow-up time of 16 years (the maximum follow-up was at 22 years

the women who took tamoxifen were at increased risk of endometrial cancer. This cancer - which is a known side effect of tamoxifen - was 3.8 times more common in the tamoxifen group during treatment, though the researchers found no increased risk in the follow-up period. Five women in the tamoxifen group died from endometrial cancer.

What is Endometrial Cancer?

Endometrial cancer is a gynecological cancer that arises from the endometrium (the lining of the uterus or womb). It is the result of the abnormal growth of cells that have the ability to invade or spread to other parts of the body.
-The first sign is most often vaginal bleeding not associated with a woman's period.
-Other symptoms include pain with urination or sexual intercourse, or pelvic pain.
Endometrial cancer occurs most commonly after menopause.

Endometrial cancer is also associated with excessive estrogen exposure, high blood pressure and diabetes.

Treatment For Endometrial Cancer

The leading treatment option for endometrial cancer is abdominal hysterectomy (the total removal by surgery of the uterus), together with removal of the fallopian tubes and ovaries on both sides, called a bilateral salpingo-oophorectomy. I