Primary Lung Cancer in Vitro Models and Patient-Derived Organoids from Minimally Invasive Procedures: A Review of Methods and Translational Potential

Primary cultures and organoids from lung cancer patients preserve tumor heterogeneity and enable patient-specific functional testing. Their generation has relied largely on surgical resection, which most patients never undergo because their disease is diagnosed too late. This review examines whether minimally invasive sources, namely cryobiopsy, endobronchial ultrasound-guided transbronchial needle aspiration, bronchoscopic biopsy, computed tomography (CT)-guided transthoracic needle biopsy, and malignant pleural effusion, can serve as alternatives. To compare outcomes across studies, we distinguish four endpoints: tissue adequacy, initial formation, long-term validated establishment, and molecular fidelity to the source tumor. Reported establishment rates from these sources range from 10% to over 80%. In the one study that applied a single protocol and a single stringent endpoint across sources, validated establishment was 3/9 for bronchoscopic and EBUS-TBNA sampling of primary tumors, 12/52 for resection and 10/100 for EBUS-TBNA of metastatic lymph nodes, and these within-study numbers are too sparse to show whether minimally invasive sources perform better or worse than resection. Yet these figures depend on how success is defined. In one cohort, organoids formed from 41% of specimens, but only 17% yielded verified tumor organoids. In another, cancer-associated fibroblasts dominated 46 of 51 cultures. Anatomical site, medium composition, and overgrowth by stromal or normal airway cells therefore explain outcomes better than acquisition route alone. Ex vivo drug responses have been linked to clinical outcomes, but prospective validation is lacking. Standardized multi-endpoint reporting and routine confirmation of molecular fidelity are needed before these models can guide therapy.