Tamoxifen is usually taken for five years after treatment, and claims a success rate of reducing deaths by a third for the first fifteen years after diagnosis. Because the drug remains effective for ten years after it is taken, scientists aimed to discover if taking tamoxifen for a ten year period would result in two decades’ effect in slowing cancer.
The international ATLAS study surveyed almost 7,000 sufferers of ER+ breast cancer, all of whom were undertaking tamoxifen treatment. Half of the women stopped after their five year course as usual, and half continued with the medication for a ten year period. All of these women continued to be observed for the following decade after stopping their treatment. In the early years of the study, little difference between the two groups was observed, as was expected. However, significant results were found after the tenth year of observation. Women who took tamoxifen for ten years were found to have an increased survival rate in the second decade after completing their treatment. The conclusion of the study was that this risk was further decreased by about 25%.
The study has been gratefully received by cancer researchers, for whom the desirability of taking longer courses of tamoxifen required more clarity. Tamoxifen can be disruptive to the wellness of post-menopausal sufferers. There is also the question of what aromatase inhibitors can do to the body and general wellbeing. As with all research that shows such a strong and measurable increase to survival rate, we hope that this will be the platform for even more hopeful news in the future.