While its diagnostic and prognostic roles in breast cancer are established, limited studies have examined cfDNA dynamics in relation to molecular subtypes and mutation profiles, particularly in underrepresented populations.<h4>Objectives</h4>To assess the diagnostic and predictive utility of cfDNA in breast cancer by analyzing its association with molecular subtypes, TP53 and PIK3CA mutations, and treatment response across dual timepoints.<h4>Methods</h4>Fifty histologically confirmed breast cancer patients and 20 age-matched healthy controls were enrolled. The gene discussed is PIK3CA; the disease is breast cancer.