E-Book

E-Book 2nd Congress

  • New Endocrine Therapy Methods for Breast Cancer Patients with Low Positive ER
  • Jalal Ghorbani,1,* Mina Soleimani,2 Mohammad Sina khanbabazadeh,3 Elyas moghadas khorasani,4
    1. Department of Laboratory Sciences, Faculty of Paramedical, Mashhad Branch, Islamic Azad University, Mashhad, Iran
    2. Department of Laboratory Sciences, Faculty of Paramedical, Mashhad Branch, Islamic Azad University, Mashhad, Iran
    3. Department of Laboratory Sciences, Faculty of Paramedical, Mashhad Branch, Islamic Azad University, Mashhad, Iran
    4. Department of Laboratory Sciences, Faculty of Paramedical, Shahrud Branch, Islamic Azad University, Shahrud, Iran


  • Introduction: Cancer is a genetic and epigenetic disease so epigenetic mechanisms regulate its many aspects. As a heterogeneous clinical and biological disease, breast cancer is the most common malignancy in women worldwide, which includes various conditions. Since 2/3 of breast cancers have hormone receptors. The test of hormone receptors (HRs) is mainly the goal of treatment choices for patients with this type of cancer. Patients show better performance with treatment methods such as endocrine therapy (ET), compared to methods such as chemotherapy and immunotherapy. The estrogen receptor ER and progesterone receptor PR test was published for the first time in 2010 in America to improve analytical performance and diagnostic accuracy in the early symptoms of breast cancer and its diagnosis. The status of estrogen receptors plays a key role in clinical decisions. Clinical implications and prediction of outcomes for patients with invasive breast cancer IBCs and, ER-mediated signaling play a significant role in tumorigenesis, tumor progression, and treatment resistance. IHC immunohistochemical test is an accurate diagnostic method for ER. Tumors that are more than 10% positive by nuclear staining with IHC are called ER-positive, which comprise 79-84% of patients eligible for endocrine therapy. Patients with ER staining < 1% are called ER-negative, and patients with such tumors have to use chemotherapy, which leads to worse results. However, tumors of 3 to 9% of patients with ER staining are in the 1 and 10% range, which are called ER Low Positive. This category of patients usually has larger cancerous tissues than the carcinomas of ER-positive patients.
  • Methods: Relevant articles and updated information were extracted from the World Health Organization (WHO) and reliable scientific databases such as PubMed and Google Scholar search engines.
  • Results: In the guidelines of 2020, there is limited data on improvement in endocrine therapy for ER-positive people between 1 and 10%. This group of patients is a significant portion of the whole population. Studies have shown that there is a tendency to resistance to ET in this group of patients. Although low ER expression has a lower prognosis in patients with breast cancer, still, endocrine therapy is recommended. However, ET alone cannot have any effect on this group of patients. Patients with low-positive ER who received ET for more than three years had a higher residual disease-free DFS than those who received ET. New studies have shown that drugs including aromatase inhibitor or tamoxifen sequentially followed by another aromatase inhibitor (AI/T+AI) along with ET can be an effective therapeutic alternative in patients with low positive ER. Patients treated with AI/T+AI can also benefit from adjuvant radiotherapy and trastuzumab. Other results have shown that patients with low ER-positive breast cancer who received sequential tamoxifen monotherapy followed by an AI had more favorable breast cancer-specific BCSS residuals than those who received ET alone. However, patients treated by AI/T+AI had no survival advantage. Other results have shown that the behavior and response to treatments for ER-low breast cancer are similar to treatments for triple-negative TNBC breast cancer, which accounts for 1/5 of breast cancers.
  • Conclusion: There has been no specific standardization for the treatment methods of breast cancer patients with low positive. In addition, in the proposed new treatments such as AI/T+AI, the side effects of tamoxifen and AI such as endometrial hyperplasia, and embolism in the coagulation system should be considered in the long term. Considering the similarity of the treatment of these patients along with other different types of cancer, our hypothesis is that the previously investigated methods along with the new methods with a larger sample size and higher accuracy tests on ER as well as on PR can lead to more consistent results in terms of the treatment of these patients.
  • Keywords: ER Low Positive / Breast Cancer / Estrogen Receptor / Progesterone Receptor/ Endocrine Therapy