Comprehensive Analysis of Six Biomarkers Expression in Early-stage Breast Cancer: A Cross-sectional Study

Introduction: Breast cancer is a heterogeneous disease with variable molecular profiles. This study aims to evaluate the expression of estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), phosphatidylinositol-4,5- bisphosphate 3-kinase catalytic subunit alpha (PIK3CA), interleukin-8 (IL-8), and antigen Kiel 67 (Ki-67) in early-stage breast cancer and their associations with clinicopathological features. Methods: Tissue samples from 93 early diagnosed breast cancer patients, attending Al- Andalus Hospital in Baghdad, Iraq, from February 2022 to April 2023, were analyzed using immunohistochemistry. Expression patterns of the six biomarkers (ER, PR, HER2, PIK3CA, IL-8, and Ki-67) were correlated with tumor grade, histological type, tumor size, and lymph node involvement. Statistical analyses included chi-square and Fisher’s exact tests as well as various correlation coefficients (Pearson, Spearman, and phi). Results: ER and PR positivity were inversely associated with tumor grade, while HER2, PIK3CA, and Ki-67 showed positive correlations. In addition, invasive ductal carcinomas mainly expressed ER+/PR+ profiles, while invasive lobular carcinomas showed higher rates of HER2 positivity compared to ductal carcinomas. Furthermore, increasing tumor size and higher degrees of lymph node involvement were positively correlated with increased expression of HER2, PIK3CA, and Ki-67. Moreover, a strong positive correlation was observed between IL-8 and Ki-67 expressions. Discussion: The study reported distinct molecular profiles associated with various clinicopathological features. In particular, well-differentiated tumors predominantly displayed hormone receptor-positive subtypes, while poorly differentiated tumors showed more aggressive molecular profiles. The findings confirm the complex relationship between some biomarkers and tumor characteristics. Conclusion: The current study’s analysis gives information about the molecular shape of early-stage breast cancer. The reported associations between biomarker expression and clinicopathological features may add to improved prognostic assessment and treatment strategies for breast cancer patients.