Table 1.

Comparison of different cytological preparation methods

Cytological preparations	Strength	Shortcoming	Ref
Conventional direct smear	The process is simple, fast and economical Cells remain intact, with high quality DNA and RNA	Lower sensitivity due to cells overlapping, cell loss and chaotic background Remaining discarded fluids may be informational The coverslip needs to be removed	[25,29,34]
Cytospins	The collected samples can be fully utilized Cells remain intact, with high quality DNA and RNA	The coverslip needs to be removed	[38,41]
Liquid-based preparations	The background is clear Unstained slides can be used for other tests Cells are well preserved, with high quality DNA and RNA	The coverslip needs to be removed	[30,31]
Cell blocks	Cellular details are well preserved Numerous sections facilitate multiple analysis and archival storage Serving as a bridge connect cytology and histology	Formalin fixation affects DNA quality	[13,29,34-37]
		The process is labor-intensive and time-consuming
		Limited application when there are few cells
Patient-derived cancer models	Biological and molecular characteristics of human tumors are accurately recapitulated	These procedures are time-consuming, expensive, and not available in every laboratory	[12,47-50]
	The models can be applied to learn biological behaviors, choose treatment plans, observe drug responsiveness, and predict treatment effects	Success rate is limited, discrepant in different tumors