| Tissue biopsy |
| Patient discomfort |
| Restricted or extremely risky access possibilities |
| Difficult to repeat (re-biopsies) |
| Tissue sample does not reflect the status of multiple sites |
| Tissues are usually collected months or years before treatment |
| A difficult tissue sample to run all the molecular tests |
| Impractical for periodic monitoring for progression/treatment resistance |
| Liquid biopsy |
| Non-invasive |
| Easily repeated |
| A blood sample can provide genetic information of the whole neoplastic process (primary and metastases) |
| Real-time monitoring: CTC persistence after treatment |
| Diagnostic: biomarker assessment for molecular profiling to choose the targeted agent |
| Prognosis: prediction of drug-response and resistance to treatment |
