Advantages and pitfalls of the different methods of cytological sampling for molecular profiling of nonsmall cell lung cancer
| Sample | Diagnostic accuracy | Advantages | Pitfalls |
| EBUS-TBNA | Sensitivity >95% | Histologic diagnostic, staging and molecular profile at the same time | Relatively invasive |
| cfDNA | Good sensitivities >95% (EGFR, KRAS, BRAF) | Noninvasive Rapid, simple monitoring Early detection or acquired resistance (EGFR T790M) | Low number of mutated alleles among wild-type alleles |
| CTCs | Sensitivity 78% (KRAS) Sensitivity 92% (EGFR) | Noninvasive Possibility of: - Cytomorphological analysis - FISH (ALK) - ICC (ALK) | Expensive and laborious Lack of standardisation Multiplicity of methods |
| Pleural fluid | 88% sensitivity | Possibility of multiplexed molecular testing if previously centrifuged | Contamination by haematopoietic cell DNA |
| Bronchoalveolar lavage | Sensitivity 16% (Sanger) to 81% (NGS) | Good sensitivity with NGS | Low number of tumour cells Poor sensitivity with conventional sequencing methods |
EBUS-TBNA: endobronchial ultrasound transbronchial needle aspiration; cfDNA: circulating free DNA; CTCs: circulating tumour cells; FISH: fluorescence in situ hybridisation; ICC: immunocytochemistry; NGS: next-generation sequencing.