Mutation-Associated P53 Immunohistochemical Patterns in Invasive Breast Carcinoma: Clinicopathological Correlations

<jats:p>Objective: TP53 mutations are the most common genetic changes in human malignancies. Recent studies suggest that specific p53 immunohistochemical staining patterns may reflect underlying TP53 mutations and have prognostic significance. This study aimed to evaluate the predictive and prognostic importance of p53 immunohistochemical staining patterns in invasive breast carcinoma. Methods: A total of 345 patients with invasive breast carcinoma were included in the present study. p53 immunohistochemistry was evaluated and categorized as wild-type, overexpression, null, cytoplasmic or equivocal. Clinicopathological variables were compared statistically. Results: Wild-type p53 staining was observed in 243 (70.4%) cases, whereas abnormal p53 staining were detected in 90 (26.1%) cases. Abnormal p53 expression were associated with a younger patient age (median 48 vs. 52 years, P=0.041), larger tumor size (29 vs. 22 mm, P&lt;0.001), higher histological grade (P&lt;0.001) and higher Ki-67 levels (P&lt;0.001). Hormone receptor negativity was significantly more frequent in tumor with abnormal p53 staining (ER negativity: 63.3% vs. 9.1%; PR negativity: 65.6% vs. 21.0%; both P&lt;0.001). HER2 positivity was also more prevalent in the abnormal p53 group (P&lt;0.001). Triple-negative breast cancer was significantly more prevalent in tumor with abnormal p53 expression 43.3% vs. 6.6%, P&lt;0.001. Additionally, lymph node metastasis was significantly more prevalent in the abnormal p53 group (75.6% vs. 56.8%, P=0.003). Conclusion: Abnormal p53 staining patterns are strongly associated with adverse clinicopathological features and aggressive molecular subtypes in invasive breast carcinoma. These results suggest that p53 staining patterns could be used as a practical surrogate marker to reflect tumor aggressiveness and provide prognostic information in routine pathological evaluations. </jats:p>