Background: Breast carcinoma is a malignancy that occurs from breast cells that grow and continue to proliferate uncontrollably. S100A4 has the potential to increase tumor metastasis in preexisting tumorigenic breast cancer. S100A4 protein expression level is associated with poor prognosis in breast cancer. Objective: To analyze the relationship between immunohistochemical expression of S100A4 with histopathological grading and molecular subtypes in invasive breast carcinoma of no special type. Methods: Formalin-fixed tissue paraffin blocks from 42 invasive breast carcinomas of no special type were used as research samples and S100A4 immunohistochemical staining was assessed. The relationship between S100A4 expression and histopathological grading and molecular subtypes was analyzed by statistical tests using the SPSS program. Results: Based on the histopathological grade, grade 3 was 18 samples (42.9%), grade 1 was 10 samples (23.8%), and grade 1I was 14 samples (33.3%). Based on the molecular subtype, Luminal A as many as 16 samples (38.1%), HER2-enriched as many as 12 samples (28.6%), Luminal B as many as 12 samples (28.6%), and Triple-negative as many as 2 samples (4.8% ). Immunohistochemical expression of S100A4 was positive in as many as 33 samples (78.6%). Conclusion: There is a significant relationship between the immunohistochemical expression of S100A4, either with histologic grading or with molecular subtypes in Invasive Breast Carcinoma of No Special Type (NST) p (0.034) < 0.05 and p (0.039) < 0.05)

molecular subtypes

invasive breast carcinoma of no special type

histological grading