Circulating cell-free DNA as an integrative biomarker in breast cancer: correlation with molecular subtypes, mutation status, and treatment response

cfDNA levels reflect tumor burden, subtype biology, and mutation status, offering real-time, non-invasive insight into disease dynamics. The high E545K and rare H1047R frequencies suggest underexplored, population-specific genomic patterns. cfDNA trends across subtypes range from persistent elevation in TNBC to decline in Luminal A, suggesting its potential role in treatment monitoring. These findings underscore cfDNA's relevance to evolving precision oncology frameworks, particularly in biopsy-limited and resource-constrained settings.