In this blog, I combine two topics: thyroid cancer and breast cancer. I am a " survivor" of both types of cancer, but I usually write many more blogs relating to thyroid cancer than breast cancer. The reason for this, is that I feel that thyroid cancer is still under- reported, you might say, especially in comparison to breast cancer.
During my nine month check up for breast cancer this year, my oncologist brought up the subject of: "So, how long do you want to take your Letrozole?" For the blissfully uninformed, Letrozole is classified as a aromatase inhibitor type drug, which is used in postmenopausal women who had the hormone receptor positive type of breast cancer. It can be given to premenopausal women who have taken a few years of Tamoxifen, or prescribed as a first line of therapy for postmenopausal women. These types of drugs, Anastrozole and Letrozole, ( aromatase inhibitors) as well as Tamoxifen, are estrogen blocking drugs. They are given to lessen the chance of a recurrence of breast cancer. Sounds great, right? As with any medication given, the benefits versus the side effects for the patient need to be taken into consideration.
The benefit of Letrozole is that it is very effective( 98.9% in a study cited by the British Journal of Cancer ) in preventing a DR ( distant recurrence- in other words, cancer in another part of the body). When I looked up the drug profile for Letrozole, I found that there are THREE pages of side effects! Sure, some of them are "minor", and when I was working as a pharmacist, I always told people that in the side effects profile sheet that now accompanies each drug dispensed, the drug companies have to list every side effect- from major to extremely minor( or rare ,statistically.) I have personally experienced a lot of side effects from this drug. My doctor first prescribed Anastrozole, which I had to stop due to extreme muscle and bone pain. He switched to the Letrozole. Although both drugs are in the same class of drugs, some people have less side effects with one or the other. I do indeed have less bone and muscle pain with the Letrozole. It is still bothersome, but I can tolerate it.
The side effect that is troubling me, is the fact that the aromatase inhibitor drugs, in lowering the amount of estrogen in the body, cause a negative effect on bone cells. This can lead to osteoporosis and broken bones. Before I started taking the estrogen blocking drugs, my bone density was great. Now, however, I am considered to have osteopenia, which is just a step behind osteoporosis. I am seeing my endocrinologist in a couple of weeks for my big thyroid cancer check up. She has scheduled a bone density test so that we can see if I am still in the osteopenia stage, or have moved up to full blown osteoporosis. I am doing all that I can myself to try to prevent osteoporosis. I can not take calcium supplements ( I had a kidney stone caused by calcium supplements, and I sure do not want to go there again!) I do take a prescription strength of Vitamin D, once or twice weekly- depending on how much sunlight I am getting. I also try to eat calcium rich foods. I read an interesting study on kidney stones, which I will not report in depth here, but the gist of the study said that the calcium that one gets in foods does not seem to cause kidney stones. Also, I try to walk every day. Weight bearing exercises are good for the bones- think lifting 5-10 pound weights a few times a week.
At my last visit with my oncologist, when he asked me how long I wanted to be on the Letrozole, I honestly did not know what to say. I am four years out from breast cancer. At my next 9 month visit, I will be almost 5 years out and need to make a decision. Quality of life is important. And I am not just talking possible osteoporosis here. I will not mention all of the side effects that I have from this drug, but they are significant to me and do affect the quality of my life. My oncologist suggested a test that may help us determine how long that I could benefit from being on the estrogen blocking drug. The test is called the BCI( breast cancer index) test and will be performed on a sample of my cancerous breast(s) tissue. I like to think that I am well informed, but I did not know that I had frozen cancerous tissue in a lab somewhere. I am thankful for this, just unaware until now. The test results will take six weeks to get back to the doctor. I asked the nurse for a copy of my report, and she said that it will be mailed out to me. However, the nurse said that my oncologist would also call me on the phone to talk to me about the results. There is a numerical scale that predicts one's chances of DR ( distant recurrence). Tumor size, staging of the cancer as well as other factors also should factor in on the decision to continue taking an estrogen blocking drug for more than five years, or stop after five years.
The BCI test is fairly new, but has been studied and reported in various well known and prestigious professional journals.( one example is the " Journal of Clinical Oncology 36, abstract," published June 1st, 2018.) I wanted to write this blog to make others aware of this test. I was not aware of the test until this month. I think that it is good information to have when making a decision concerning how long a person should be on the estrogen blocking drugs. One must work closely with their physician, of course, but ultimately, the decision rests on the cancer patient. Having a test like the BCI can help the patient make a more informed decision. I hate the side effects of the Letrozole, but i certainly do not want a recurrence of my cancer. I had two areas of cancer- three tumors were "stacked" on each other in one area, and there was another area of cancerous cells not related to those tumors. My staging was IIb, according to my oncologist. My oncologist did not recommend radiation, but I had three months of aggressive chemotherapy. I will consider these factors when I make my decision, as well as my results from the BCI test. I urge breast cancer patients to inquire about this test, if you have not already. It can be another weapon in our arsenal in fighting breast cancer.
No comments:
Post a Comment