Estrogen receptor (ER)-positive breast cancer is the most common type of the disease, accounting for a significant portion of distant metastasis and fatalities. The mechanisms behind its long-term risk are not fully understood, but dormant cancer cells that become active due to unknown environmental factors are suspected. Traditional adjuvant endocrine therapies, such as tamoxifen and goserelin, have been employed to reduce the risk of metastasis. However, accurately predicting the long-term risk and potential benefits of these therapies remains a clinical challenge due to the absence of long-term clinical trials.
Unveiling Long-Term Risks and Benefits of Endocrine Therapy
A recent thesis sought to shed light on the long-term risks and benefits of endocrine therapy in ER-positive breast cancer patients. The research was divided into four studies. The first study established that tumor size, tumor grade, and progesterone receptor (PR) positivity significantly influence long-term survival and the benefits of tamoxifen in postmenopausal women with lower clinical risk.
Genomic Risk and Therapy Benefits
The second study demonstrated long-term benefits of endocrine therapy in premenopausal patients. Gene expression analysis indicated that those with low genomic risk reap long-term benefits from tamoxifen. In contrast, those with high genomic risk see early benefits from goserelin, a hormone therapy often used in breast cancer treatment.
Tamoxifen and Less Aggressive Tumors
The third study displayed a long-term benefit of tamoxifen for patients with less aggressive tumors, regardless of tumor size, in both premenopausal and postmenopausal patients. The final study indicated that patients with the luminal A molecular subtype of ER-positive/HER2-negative breast cancer derive long-term benefits from tamoxifen, while those with the luminal B subtype gain short-term benefits. Tumor size and menopausal status further influenced the benefit, with postmenopausal luminal A patients with larger tumors and premenopausal luminal B patients with smaller tumors experiencing more benefit.
These findings highlight the importance of personalizing endocrine therapy and understanding the diverse nature of ER-positive breast cancer to optimize treatment outcomes. The insights gained from this research underscore the need for continued exploration and innovation in the field of breast cancer therapy. The complexity of ER-positive breast cancer demands a nuanced approach to treatment that considers all potential risk factors and promises the best possible outcomes for patients.
