10 vs. 5 Years of Tamoxifen
Hello. I'm Debu Tripathy, an editor-in-chief from Cure Magazine. I'm in San Antonio at the very beginning of the meeting. As usual there's a buzz with people from all over the world coming. It's always such an international audience and a very engaged audience. A lot of questions are being asked to the investigators. So, it's really an opportunity not only to exchange information, but to hear what our colleagues think about the different trials that are being presented.
The first one that was presented was the first presentation of an eagerly awaited trial looking at more than the usual five years of Tamoxifen. So, we have been using Tamoxifen as a hormonal therapy to lower the risk of recurrence after the treatment for early-stage breast cancer for several decades now. We know that it's a very effective drug. It cuts the recurrence rates by about a half. And we also know that it works mostly in patients that have estrogen receptor positive cancers. Also we know that five years appears to be the best time frame to take it. It's been shown to be better than one year or two years.
But the remaining question is: after those five years, what do you do? Patients are still at risk for recurrence after those five years. And there has been a lot of interest in knowing whether we can go beyond five years, and there have been smaller studies that have been done over the last few years that have not really given us a clear answer.
So, almost 15 years ago individuals in the in England decided to put together a worldwide file comparing 5 vs. 10 years. And at the point, at which the doctor felt that they would normally stop Tamoxifen, which was typically five years, they would be randomized to stopping then or go for a full ten years. So, what exactly 5 vs. 10, it was when the physicians thought someone should stop, but mostly it was five vs. 10, and what it showed is that there was about a 3% drop in the mortality rate and about a 3-4% drop in the recurrence rate.
It did not become apparent until about 10 years later after the randomization. So, it was a delayed effect. So, this is good news. What it means is that we do have another tool for longer term therapy that can further lower the risk of recurrence. Now, it mostly pertains to women, who were still premenopausal, still having menstrual periods after their five years of Tamoxifen, because, otherwise, we would use a new class of drugs called aromatase inhibitors. So, now, when women hit the five-year mark of Tamoxifen, they should definitely check with their doctors to see if more hormonal therapy might be indicated in their case. This is really a practice changing finding and the full publication will be out very soon.