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Melatonin MT1 Receptor Expression in Luminal Invasive Ductal Breast Carcinoma in Postmenopausal Women
Leda Pistiolis1,2, Sahar Alawieh3, Thorhildur Halldorsdottir4
1Department of Surgery, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, 41390 Gothenburg, Sweden.
Abstract:
Laboratory and animal studies indicate that melatonin exerts a negative impact on breast cancer progression and metastasis. These actions are both receptor-dependent and -independent. Of the two transmembrane melatonin receptors identified in humans, breast cancer expresses only MT1. The aim of this study was to investigate the expression of MT1 in hormone-receptor-positive, HER2-negative invasive ductal breast carcinoma in postmenopausal women and its possible correlations with clinicopathological parameters and survival. A total of 118 patients with luminal A/B primary breast cancer with or without axillary metastases were identified. The MT1 receptor expression was immunohistochemically assessed as a percentage of stained cells and a weighted index (WI) (percentage multiplied by staining intensity). Most tumor samples (84.7%) and metastasized lymph nodes (96%) stained positive for MT1, with varying intensity. No statistically significant correlations were found between the MT1 expression or the WI in the primary tumor and the patient and tumor characteristics, or the MT1 and WI in the metastasized lymph nodes. The survival analysis did not reveal a significant effect of MT1 expression or the WI on the risk of recurrence or survival.
Insights
Melatonin receptor MT1 is highly expressed in hormone-receptor-positive breast cancer. However, MT1 expression did not correlate with clinicopathological features or patient survival in this study population.
Area of Science:
- Oncology
- Endocrinology
- Molecular Biology
Background:
- Laboratory and animal studies suggest melatonin inhibits breast cancer progression.
- Melatonin exerts its effects via receptor-dependent and -independent pathways.
- The MT1 receptor is the primary transmembrane melatonin receptor expressed in human breast cancer.
Purpose of the Study:
- To investigate MT1 receptor expression in hormone-receptor-positive, HER2-negative invasive ductal breast carcinoma in postmenopausal women.
- To explore correlations between MT1 expression and clinicopathological parameters.
- To assess the relationship between MT1 expression and patient survival outcomes.
Main Methods:
- Immunohistochemical assessment of MT1 receptor expression in 118 primary breast cancer samples and corresponding axillary lymph nodes.
- Quantification of MT1 expression using percentage of stained cells and a weighted index (WI).
- Correlation analysis with clinicopathological parameters and survival data (recurrence risk, overall survival).
Main Results:
- MT1 receptor expression was detected in the majority of primary tumors (84.7%) and metastasized lymph nodes (96%).
- No statistically significant correlations were observed between MT1 expression (or WI) and patient/tumor characteristics.
- No significant association was found between MT1 expression and the risk of recurrence or patient survival.
Conclusions:
- MT1 receptor is widely expressed in hormone-receptor-positive, HER2-negative invasive ductal breast carcinoma.
- MT1 expression levels in primary tumors or lymph nodes do not appear to be a significant prognostic biomarker in this patient cohort.
- Further research may be needed to elucidate the role of melatonin signaling in this specific breast cancer subtype.
