Aug 13, 2012 12:23AM Beesie wrote:
Kathy, who was the doctor who told you that you should take Tamoxifen? Was it your surgeon or was it an oncologist?
Tamoxifen usually is not recommended after a bilateral mastectomy for DCIS (or any other pre-invasive condition or pre-cancerous condition). This is because the risk of a recurrence or new BC after a bilateral MX for DCIS usually is only about 1% - 2% (assuming adequate surgical margins). Tamoxifen can cut this risk by about 45%, but with such a low risk to being with, the benefit from Tamoxifen is at most 1% (a 50% reduction of a 2% risk). Overall Tamoxifen is a very safe drug but like all drugs it comes with the risk of side effects. Most of the side effects from Tamoxifen affect quality of life and do not present serious health risks however there are a number of small but very serious possible health-related side effects. Depending on one's age and overall health, the risk of serious side effects from Tamoxifen can range from about 1% to about 3%.
What this means is that the risk of serious side effects from Tamoxifen, even though very low, can range fom 1% - 3%, whereas the benefit from Tamoxifen in terms of the reduction in BC risk is only about 1% for someone who's had a BMX for DCIS. So by taking Tamoxifen you might actually be putting yourself at a greater overall health risk. This is why standard of care guidelines do not recommend Tamoxifen for those who've had a BMX for DCIS.
Obviously for those who've had a lumpectomy and have a greater recurrence and/or new BC risk, or for those who have invasive cancer and have a risk of mets, the benefit from Tamoxifen in terms of risk reduction can be quite different. For example, if recurrence risk after a lumpectomy is 10%, Tamox. can cut this risk to 5.5%. This benefit from Tamoxifen is greater than the risk of taking Tamoxifen. This is why Tamoxifen is usually recommended to women who've had a lumpectomy for DCIS. Similarly, the fact that Tamoxifen can reduce the risk of mets is extremely significant to women who have invasive cancer, and that's why Tamox. is usually recommended to women who have invasive cancer, even if they've had a BMX (the risk of mets isn't affected or reduced by a BMX). The benefit vs. risk equation for Tamox. is completely different in these situations than it is for someone who's had a BMX for DCIS.
Hope that makes sense.