Strong Mammaglobin-A Expression in Tumor Tissue as a Risk Factor for Metastasis in Balinese Breast Cancer Patients

Mammaglobin (hMAG) is a secretory protein (secretoglobin) essential for tumor growth. The molecular mechanisms of hMGB-A-regulated growth include the expression and activation of various Mitogen-Activated Protein Kinase (MAPK) pathways. Elevated hMAG signifies metastatic breast cancer and primary breast cancer compared to non-malignant breast tissue. This study aimed to prove the relationship between mammaglobin A expression and metastasis at Prof. I.G.N.G. Ngoerah Hospital Bali. This is an observational study with a case-control design, conducted in the Oncology Department of Prof. I.G.N.G. Ngoerah Hospital Bali. Secondary data were collected from medical records which included the results of clinical data, histopathology, and immunohistochemistry. Data analysis was carried out with the help of SPSS version 25, which included the stages of descriptive analysis, bivariate tests with Chi-Square, Mann Whitney, and independent t-test. A total of 48 subjects were divided into 2 groups, 24 subjects in the metastasis group and 24 subjects in the non-metastasis group. Age, menstrual status, parity, histopathological grading, and breast cancer subtypes showed no significant differences between the two groups. The metastatic group had a larger tumor size with more lymph node metastasis than the non-metastatic group (p<0.001). The most common metastatic organ was in the lungs. The difference in the presence of Mammaglobin A expression in metastases had an RR of 22.0 (95%CI = 4.1-117.8; p<0.001) with the results of the percentage of strong expression with the metastatic group having a mean of 55.0% ± 31.8% and not metastatic 7.5% ± 11.9% (p<0.001). The results of weak expression found no significant difference in the two groups with a value of p=0.376. In conclusion, strong mammaglobin A expression increase the risk of metastasis in breast cancer by 22 times.