Table 1. Comparison of the sensitivity of the CTC cluster assay and conventional CTC expansion techniques. N.D., not determined.

Cancer type	Samples validated	Duration	Culture type	Pre- enrichment	Efficiency in culture	Correlation to treatment	Reference
Breast	36	>6 months	Cell lines, long-term	Yes	16.70%	N.D.	(8)
Breast	8	<1 month or ≧1 month	Colonies (short-term) or cell lines (long-term)	Yes	37.50%	N.D.	(7)
Colon	71	>2 months	Cell lines, long-term	Yes	2.80%	N.D.	(52)
Prostate	17	>6 months	Organoid lines, long-term	Yes	~15–20%	N.D.	(9)
Breast	73	2 weeks	Primary CTC cluster (short- term)	No	19.6–59.3% (depending on treatment time point)	Yes	This work