Likvidibiopsiat

Likvidibiopsiat, also known as liquid biopsy, refers to the analysis of non-solid tissue samples, most commonly blood, to detect disease biomarkers derived from tumors. Unlike conventional tissue biopsy, it relies on circulating biomarkers such as circulating tumor DNA (ctDNA), circulating tumor cells (CTCs), exosomes, and other extracellular vesicles.

The most frequently studied analyte is ctDNA, fragments of tumor DNA present in plasma. CTCs are intact tumor cells shed into the bloodstream. Exosomes and other extracellular vesicles carry molecular cargo from tumors. Laboratory methods include targeted and broad mutational profiling with next-generation sequencing (NGS), digital PCR, methylation assays, and enrichment-based isolation of CTCs.

Clinical applications include monitoring treatment response, detecting minimal residual disease after surgery or therapy, and identifying resistance mutations to guide treatment, such as mutations in EGFR or KRAS. It also holds promise for early cancer detection and for assessing tumor heterogeneity when tissue sampling is impractical.

Limitations and considerations include variable sensitivity depending on cancer type and disease burden, potential false positives from clonal hematopoiesis or benign processes, and the need for standardized pre-analytic handling and validated assays. Liquid biopsy generally complements rather than replaces tissue biopsy in current practice.

The field is rapidly evolving, with ongoing research to improve sensitivity, specificity, and clinical utility. Regulatory approvals and guideline recommendations are increasing, and integration into routine oncology care is becoming more common as evidence accumulates.