摘要Background:This study investigated the multifaceted role of BRCA2 (breast cancer 2) in various cancer types,with a specific focus on thyroid carcinoma (THCA).Methods:Data sets were obtained from the University of California Santa Cruz database to analyze BRCA2 expression,genetic alter-ations,and clinical implications.Sample filtering criteria were applied,and immunohistochemistry from the Human Protein Atlas was used to validate protein expression.Correlation analyses were used to explore associations between immune-related genes,and immunological signatures were assessed using various tools.Genetic alterations in BRCA2 were analyzed using cBioPortal,and prognostic analysis in-volved evaluating gene expression differences at different clinical stages of THCA.Results:In patients with THCA,differences in BRCA2 expression were observed at both the mRNA and protein levels when comparing tumor and normal tissues.Correlation studies revealed associations between BRCA2 and immune-related genes,emphasizing its poten-tial role in modulating the tumor microenvironment.Immunological signature analyses indicated distinct frequencies of tumor-infiltrating immune cell subsets in BRCA2 high versus low tumors.Moreover,genetic alterations in BRCA2,particularly the A2738S mutation in exon 18,have been identified in patients with THCA.The prognostic analysis demonstrated a significant correlation between altered BRCA2 levels and improved overall survival in patients with THCA.Additionally,BRCA2 expression was associated with prognostic factors such as stage and N.Conclusions:This study provides a holistic exploration of BRCA2 in cancer and highlights its diverse roles in expression,immune modulation,genetic alterations,and clinical prognosis.These findings underscore the potential significance of BRCA2 as a diagnos-tic and prognostic marker and offer valuable insights for future research and potential clinical applications in cancer management.