Introduction: breast carcinoma presenting with prostate metastasis represents a rare but clinically significant entity, necessitating a comprehensive exploration of its biomarker profile. By unraveling the molecular determinants driving this unique metastatic tropism, we can pave the way for personalized diagnostic and therapeutic strategies tailored to individual patients.

Material and methods: Blood samples were collected from study participants to assess circulating biomarkers reflective of tumor burden, treatment response, and disease progression. Circulating tumor cells (CTCs) and cell-free DNA (cfDNA) were isolated from peripheral blood using established methodologies, including density gradient centrifugation and polymerase chain reaction (PCR)-based assays.

Results: Copy number analysis revealed frequent amplifications of oncogenes, including MYC (n=20, 44.4%) and CCND1 (n=16, 35.6%), coupled with deletions of tumor suppressor genes like PTEN (n=12, 26.7%) and CDKN2A (n=10, 22.2%). Furthermore, analysis of gene expression profiles unveiled distinct molecular subtypes, with luminal A (n=20, 44.4%) and luminal B (n=15, 33.3%) tumors predominating, followed by HER2-enriched (n=6, 13.3%) and basal-like (n=4, 8.9%) subtypes.

Conclusion: the comprehensive analysis of biomarkers in breast carcinoma presenting with prostate metastasis provides critical insights into the molecular underpinnings of this rare clinical entity, informing personalized therapeutic strategies and prognostication.