Table 2.

Major problems encountered in the generation and culture of lung cancer organoids and possible solutions. LCOs, lung cancer organoids; PDX, patient-derived xenograft.

MAIN PROBLEMS	POSSIBLE SOLUTIONS
LOW SUCCESS RATE (overgrowth of normal airway organoids)	Nutlin-3a Supplement (see Table 1) Growth factor deprivation of normal airway organoids [36,40,41] Extrapulmonary source such as pleural effusion or metastasis [34,35,36] Hand picking of LCOs [16,51] LCO generation from PDX obtained from primary tumor [17] or metastasis [38]
LOW YIELD OF LCO CULTURES	Pre-selection of tissue quality [16,34,40] Sample size of 1–4 cm3 [40,51] Practical tips: (a) Rapid processing (b) Digestion time established according to sample size [39,43,51] Culture medium optimization
CULTURE EXTINCTION	Mechanical dissociation during LCOs passaging [51]
LCO GENERATION TOO LONG FOR CLINICAL APPLICATIONS	Microwell array chip for rapid (1–2 weeks) LCO generation and drug testing [39]
LCO PRODUCTION IS PARTICULARLY DIFFICULT FOR EARLY STAGE TUMORS	Optimization of culture conditions [42]
LIMITED HETEROGENEITY	LCO generation from multiple biopsies from different areas of the same tumor or from both primary and metastatic tumors [16,42]