Hormonal Therapy (Part 3)

Seth and I spent hours on Friday morning talking through my fears for my treatment, and I cried more than I have at any time during this illness, including at diagnosis. He listened to my concerns and read the articles that I handed him and dried my tears, and ultimately said, "We need better information." I realized that he was right - we didn't need more information, but we needed actual data, not anecdotes. Even the articles from reputable sources were of limited helpfulness when they quoted doctors' opinions rather than facts, and many of them contradicted each other about which side effects were most likely to occur.

But then I found the results of a National Cancer Institute study called NSABP P1, wherein 13,000 women at high risk of getting breast cancer were randomly assigned to receive either tamoxifen or placebo. The primary goal of the trial was to assess the value of tamoxifen in preventing cancer, but it also included a set of questionnaires to assess the treatment's toxicity and impact on quality of life. This study was particularly valuable because it was large and because it was double blind and placebo controlled, so neither the patients nor the doctors knew who was receiving tamoxifen and who was receiving a sugar pill. This is so important in a quality of life study, where much of the data is subjective and easily influenced by bias and preconceived ideas. It also helps to isolate actual causation from effects that would have happened anyway, whether due to random chance, other underlying conditions, or both. This study showed no major or statistically significant differences in the "Physical Component Scores" or the "Mental Component Scores" between the women who got tamoxifen and those who got placebo. It showed that women taking tamoxifen could expect to maintain a good quality of life, for the most part the same as women taking a placebo.

What was really meaningful to me was the actual data from the results, which provided the incidence of certain conditions for the study group and the control group, often separated by age group. For instance, I was very concerned about depression, something I have never suffered from and never want to. The results showed that in the 35-49 age group, the incidence of depression was 14% for the tamoxifen arm and 15% for the placebo arm - meaning, amazingly, that the group that wasn't on the drug was slightly more depressed. It wasn't all good news - in the 35-49 age group, the incidence of hot flashes was 63% for the tamoxifen arm versus 45% for the placebo arm - but it was such a relief to have real numbers, rather than hearsay.

Shortly after reading about that study, I heard from Dr. Hurvitz, who I had emailed the night before. In her response, she addressed the question that no amount of online research could answer: What is my risk? I believe that I am incredibly lucky to be receiving T-DM1 and Perjeta, but the downside is that there is no data available for my exact pathology and treatment regimen - so it's impossible to say what my risk of recurrence and chance of survival are. However, Dr. Hurvitz was willing to give me "a big guess", which I really appreciated as I badly needed to have some context in which to make my decision. In her view, she said, I have an approximately 15-20% chance of distant metastatic recurrence in the next 10 years without any hormonal therapy, reduced to 10-12% with tamoxifen alone, reduced to 7-10% with AI/OFS. She went on to remind me that risk reduction continues beyond the 10 year milestone. When comparing 5 years of tamoxifen to no tamoxifen, patients even 15 years later continue to live longer and have fewer recurrences than those patients who never took tamoxifen, and the curves continue to separate over time. Her belief is that the difference between AI/OFS and tamoxifen may also widen over time, although there is no data at this time to prove that.

In closing she wrote, "My recommendation is that you start whichever one you are comfortable with and see how you do. You may be one of the people who does amazingly well. There is no way for me to tell me today if that will be you. If you have bad side effects we can switch to another type. This is an iterative process that we will work on together over time. I don’t recommend not trying anything however." In other words, at least try - the same conclusion I had come to myself. So I'm going to try tamoxifen; I think the slightly higher risk of recurrence is worth the probable improvement in quality of life. And if it's not so good, I can always switch to AI/OFS and see if that works better for me. It's been a hard process for me to get comfortable with the idea of this treatment, but at this point I'm optimistic that I will be one of the lucky ones "who does amazingly well".

Information from adjuvantonline.com.