Immunohistochemical Expression of Vimentin in Breast Carcinoma and Its Correlation With Histopathological Prognostic Factors

Background: Vimentin is a mesenchymal intermediate filament protein and an important marker of epithelial-mesenchymal transition, which has been implicated in tumor invasion, progression, and aggressive biological behavior in breast carcinoma. Its expression in invasive breast carcinoma may correlate with established pathological prognostic factors and thereby provide additional prognostic information. Objective: To evaluate the expression of vimentin in invasive breast carcinoma of female patients and to determine its correlation with markers associated with adverse histopathological features. Methodology: This retrospective observational study was carried out in the Department of Pathology, Gandhi Medical College, Bhopal, Madhya Pradesh, India. A total of 70 cases of invasive ductal carcinoma of the breast, not otherwise specified (IDC-NOS), were included. Histopathological evaluation was performed on hematoxylin and eosin-stained sections, and tumor grading was done according to the Modified Bloom-Richardson grading system. Tumor size and lymph node status were categorized according to standard pathological criteria. Immunohistochemical staining for vimentin was performed on representative paraffin-embedded tissue sections. Vimentin expression was assessed as positive or negative based on cytoplasmic staining in invasive tumor cells. Results: Vimentin expression was observed in 17 of 70 cases (24.28%). An increasing trend of vimentin positivity was seen with increasing tumor size, with positivity in 0 of 3 cases (0.0%) in tumors measuring ≤2 cm, 5 of 28 cases (17.85%) in tumors measuring >2 to ≤5 cm, and 12 of 39 cases (30.76%) in tumors measuring >5 cm. Vimentin positivity also increased with nodal involvement and was seen in 4 of 32 node-negative tumors (12.50%), 3 of 17 N1 tumors (17.64%), 8 of 18 N2 tumors (44.44%), and 2 of 3 N3 tumors (66.66%), although the association was not statistically significant (p = 0.06). A strong association was observed with histological grade: none of the Grade I tumors [0 of 19 cases (0.0%)] were positive, whereas positivity was present in 7 of 38 Grade II tumors (18.42%) and 10 of 13 Grade III tumors (76.92%). Conclusions: Vimentin expression in invasive breast carcinoma is associated with adverse pathological features, particularly larger tumor size, higher nodal burden, and most strongly, higher histological grade. Its marked expression in poorly differentiated tumors suggests that vimentin may serve as a useful adjunct prognostic marker of aggressive tumor biology in invasive breast carcinoma.