A domestic research team has announced findings that could improve the prognosis of breast cancer patients. They suggest that adding ovarian function suppressants to treatment strategies can lead to more positive responses.
Breast cancer is the most common cancer among women in South Korea, and it is categorized into several types based on its characteristics. In particular, patients whose cancer cells respond to female hormones are classified as HR (Hormone Receptor) positive, while those with the human epidermal growth factor receptor 2 (HER2) on the tumor surface are classified as HER2 positive.
About 70% of the overall breast cancer patient population falls into these two categories, and approximately 10% of patients are positive for both HR and HER2. Patients who are positive for both receive both hormone therapy and HER2-targeted therapy.
In this regard, the breast surgery research team at Gangnam Severance Hospital (Professors Ahn Seong-kyu and Bae Sung-jun) aimed to identify factors that could positively affect the prognosis of these patients by analyzing large-scale phase 3 clinical trial data of the targeted therapy drug ‘trastuzumab’ used for HER2 positive patients.
Analysis of data from 965 patients who were positive for both HR and HER2 revealed that the group receiving both hormone therapy and ovarian function suppression treatment (464 patients) had better prognoses than the group receiving hormone therapy alone (501 patients). The 10-year disease-free survival rate for the simultaneous treatment group was an average of 70.9%, significantly higher than the single treatment group (59.6%), and the overall survival rate was also markedly different, with the simultaneous treatment group at 84.7% and the single treatment group at 74%.
Additionally, the simultaneous treatment group was found to have a 32% lower recurrence rate and a 38% lower mortality risk compared to the single treatment group. According to the research team, this trend was more pronounced in patients with higher stages or grades of cancer.
Professor Ahn Seong-kyu, who led the study, stated, “Most major clinical trials conducted on breast cancer patients so far have focused primarily on HER2 negative patients,” and added, “There has been a lack of research on the treatment of early breast cancer patients who are positive for both hormone receptors and HER2.” He further remarked, “This study demonstrates that ovarian function suppressants can help improve the survival rates of such patients, and I hope it will be actively utilized in clinical practice guidelines for young breast cancer patients.”
The results of this study were published in the latest issue of the international journal 《Journal of the National Comprehensive Cancer Network (JNCCN)》.
