Table 1.

Advantages and disadvantages of current in vitro metastasis models.

	System setup	Performance	Post analysis
Transwell model	Pros	Pros	Pros
	• Easy to operate	• High throughput	• Easy to recover the cells
	• No instruments required	• No air bubble formation
	• No tubing and connection		Cons
	• Cell seeding is easy	Cons	• Additional transfer step required for observation
	Cons	• Frequent medium change for long term culture
	• Static culture	• Gravity influence
	• No physiologically relevant	• Can mimic only one step of the metastatic cascade
Current microfluidic-based metastasis model	Pros	Pros	Pros
	• Dynamic culture	• Real-time monitoring	• Compatible with microscope
	• Co-culture	• Can generate a concentration gradient	Cons
	• Physiologically relevant	• Can mimic 1–2 steps of the metastatic cascade	• Difficult to recover the cells
	Cons	Cons
	• Fabricated from PDMS	• Low throughput
	• Requires trained personnel to operate and assemble	• Air bubble formation can ruin the experiment
	• Requires a perfusion pump and other instruments
	• Requires more attention for cell seeding
This work	Pros	Pros	Pros
	• Fabricated from acrylic and PET	• Can perform long-term culture	• Easy to recover the cells
	• Easy to operate using a plug-and-play design	• No air bubble formation	• Can collect circulating cells
	• Cell seeding is easy	• Real-time monitoring	Cons
	• Dynamic culture	• Can mimic almost the entire cascade	• Additional transfer step required for observation
	• Co-culture	Cons
	• Physiologically relevant	• Requires a medium reservoir for long term culture
	Cons
	• Requires a perfusion pump
	• Requires a tubing connection
	• Additional step for cell seeding