A new study published in JAMA Oncology* by Dr. Laura Esserman (she is the Director of the Breast Cancer Program at UCSF; which just happens to be where I did my fellowship training in breast surgical oncology) identifies women who do NOT need Tamoxifen (or other similar medications referred to as Endocrine Therapy) after surgery for breast cancer. This study is a breakthrough as it now allows doctors to identify which patients may only need surgical treatment for their breast cancer. These women are referred to as UltraLow Risk and were identified by genomic profiling of their tumor. This test is called MammaPrint and I utilize it for all of my patients with hormone positive (ie. ER+) breast cancer. For women with ER+ breast cancer who are ALSO post-menopausal, lymph node negative and have tumors that are 3 cm or smaller; endocrine therapy may not provide a significant benefit, as their Breast Cancer Specific Survival after 20 years was 94% with surgery alone. For women in this group that DID take Tamoxifen, their BCSS at 20 years was 97% (not much better). This is great news for women who may be struggling with the side effects of Tamoxifen. Women who fall into this UltraLow Risk category, who are finding Tamoxifen difficult to tolerate, may safely discontinue treatment, while having the peace of mind that science “supports” their decision to forego endocrine therapy. For surgeons and oncologists, this study demonstrates how the 70-gene MammaPrint assay can identify UltraLow Risk patients who may only require surgery for breast cancer treatment.
Breast cancer treatment continues to evolve and improve. This is one of the reasons why I chose to become a breast cancer specialist. I believe each woman is unique, as is her circumstances, as well as the breast cancer itself. Doctors should continue to look for ways to personalize breast cancer treatment for their patients. Genomic profiling of the tumor itself- is the most technologically advanced and scientifically driven approach to breast cancer care and I am thankful that I get to practice medicine and surgery in a time where doctors and patients can benefit from these breakthroughs.
If you would like to review the study in more detail, I have provided a full text link to the publication below.