A recent British study has found that the anti-estrogen drug Tamoxifen has some positive long term effects against breast cancer. Tamoxifen treatment conducted among women with oestrogen receptor (ER)-positive early breast cancer, reduced the breast cancer mortality rate significantly and reduces the chances of the cancer from recurring by almost half.
In most circumstances, tamoxifen treatment is administered for 5 years among both pre-menopausal and menopausal women. For this particular study, the assessments of effects were studied by continuing the tamoxifen treatment to the length of 10 years. Funding for the trial was provided by Cancer Research UK, UK Medical Research Council, US Army, EU-Biomed and the drug's manufacturer, AstraZeneca UK.
As documented in the findings published in December, a worldwide study consisting of 12,894 women was conducted called the Adjuvant Tamoxifen: Longer Against Shorter (ATLAS) trial. The early stage breast cancer women who already completed the 5 year treatment of tamoxifen were randomly selected to extend the anti-estrogen treatment to 10 years. Yearly follow-ups between 1996 and 2005 were recorded, reporting hospital admissions, recurrences of cancer, second cancers or deaths. The outcomes among the 6,846 women diagnosed with ER-positive breast cancer from the group were reported.
It was found that extended treatment further reduces the recurrence of cancer and the likelihood of death from breast cancer. Studies show that the risk of recurrence was 21.4% in the group that continued the treatment for 10 years, compared to 25.1% among the control group who underwent treatment for 5 years. Death from breast cancer was reduced to 12.2% in the extended treatment group compared with 15% in the 5 year treatment group. "For women with ER-positive disease, continuing tamoxifen to 10 years rather than stopping at 5 years produces a further reduction in recurrence and mortality, particularly after year 10." said the report.
Tamoxifen was first approved as a form of cancer treatment by the Food and Drug Administration (FDA) in 1977. It fights cancer by blocking the estrogen hormone from binding to estrogen receptors in women whose breast cancer cells contain those receptors. Although tamoxifen was first used to treat advanced breast cancer patients, in 1998 it was approved for use among early stage breast cancer patients as well.