The International Breast Cancer Intervention Study (IBIS) confirms breast cancer drug Tamoxifen is effective in preventing the disease, however is still a high risk option.
Findings from a large international study confirm that the breast cancer drug Tamoxifen can prevent the disease in some high-risk women, but researchers say it is still unclear whether that benefit outweighs the risks associated with the drug.
Preliminary findings from the International Breast Cancer Intervention Study (IBIS) show that, among women at high risk of breast cancer, Tamoxifen cuts the odds of developing the disease by nearly one-third over 5 years.
But the study also confirmed the down side of using Tamoxifen as a preventive drug as potentially causing serious side effects, particularly blood clots.
‘We cannot recommend Tamoxifen to be given to high-risk women for the prevention of breast cancer,’ said the study’s lead author, Dr. Jack Cuzick, of Cancer Research UK in London. Furthermore ‘it will take another 5 years’ worth of data to conclude whether Tamoxifen’s benefits outweigh its risks for these women’.
His team’s findings are based on studies of more than 7,100 women in Europe, Australia and New Zealand.
Cuzick’s team found that while women given Tamoxifen were 32% less likely to develop breast cancer, they also had more than double the rate of blood-clotting complications, such as potentially dangerous clots in the legs.
Another documented risk of Tamoxifen is an increase in cancer of the uterine lining, or endometrium. In the current study, more Tamoxifen patients than placebo patients developed endometrial cancer, but the difference was not statistically significant, according to the researchers.
These findings however should not detract from Tamoxifen’s proven benefit in treating breast cancer, according to investigators. The drug, produced under the name Nolvadex by AstraZeneca, is the most widely prescribed drug for the treatment of breast cancer.
Source: Reuters News cites on ACSO website