Intracellular Fibronectin Expression in Invasive Breast Carcinoma: Is It Related to Significant Clinicopathological Prognostic Factors?

Background: Fibronectin plays a key role in the extracellular matrix. The expression of fibronectin and its impact on tumor behavior have been studied in several tumors such as breast carcinoma. Objectives: We aimed at investigating the immunohistochemical expression of intracellular fibronectin in breast carcinoma and its relationship with significant clinicopathological factors. Methods: This case-control study was conducted on 125 formalin-fixed and paraffin-embedded tissue blocks, including 50 invasive breast carcinomas (tumor group) and their adjacent normal tissue (tumor control group), and 25 normal control samples from mammoplasty (normal control group). The samples were obtained from the pathology archive of Alzahra Hospital, Isfahan, Iran, from 2016 to 2018. All the 125 samples were stained immunohistochemically by the fibronectin antibody. Intracellular fibronectin expression was then compared between the three groups. Moreover, the relationship between fibronectin expression and some clinicopathological factors was evaluated in the tumor group. Results: Fibronectin staining intensity and extent showed no significant difference between the normal control and tumor control groups (P-Value=0.65and0.065, respectively), while thetumorgroupshoweda significant differencefrombothnormalcontroland tumor control groups in fibronectin staining intensity (P-Value = 0.002 and < 0.001, respectively) and fibronectin staining extent (P-Value < 0.001). In addition, a significant relationship between fibronectin expression in tumor samples and fibronectin staining intensity and tumor grade was observed (P-Value = 0.01). However, fibronectin expression did not show any significant relationship with age, tumor size, tumor subtype, and lymph node status. Conclusions: Intracellular fibronectin expression seems to be a tendency observed in some breast carcinomas. Normal breast tissue, whether adjacent to carcinoma or normal control, does not show such a tendency. Despite the significant relationship between fibronectin expression and carcinoma grade, fibronectin expression did not show any significant relationship with tumor size and lymph node status.