Circulating tumor cells

Figures & data

Figure 1. CellSearch analysis (A) and multiplex PCR performed after isolation of CTCs with AdnaTest (B) in three exemplificative patients with metastatic colorectal cancer. The figure shows that the absence of CTC at the CellSearch analysis is consistent with lack of EpCAM expression, as visualized at the AdnaTest analysis. Conversely, the approach with the multiplex PCR allows the identification of CTC underestimated by CellSearch, through the positive expression of EGFR and CEA.

Table 1. Detection rate of CTC in metastatic colorectal cancer: comparison between CellSearch and Adnatest

	CTC AdnaTest		Total
	Negative	Positive
CTC Veridex 0 count	5	26	31
% within CTC Veridex	16.1%	83.9%	100.0%
% within CTC AdnaTest	71.4%	81.2%	79.5%
% of total	12.8%	66.7%	79.5%
CTC Veridex 1 count	1	2	3
% within CTC Veridex	33.3%	66.7%	100.0%
% within CTC AdnaTest	14.3%	6.2%	7.7%
% of total	2.6%	5.1%	7.7%
CTC Veridex 2 count	1	0	1
% within CTC Veridex	100.0%	0.0%	100.0%
% within CTC AdnaTest	14.3%	0.0%	2.6%
% of total	2.6%	0.0%	2.6%
CTC Veridex 3 count	0	1	1
% within CTC Veridex	0.0%	100.0%	100.0%
% within CTC AdnaTest	0.0%	3.1%	2.6%
% of total	0.0%	2.6%	2.6%
CTC Veridex 5 count	0	2	2
% within CTC Veridex	0.0%	100.0%	100.0%
% within CTC AdnaTest	0.0%	6.2%	5.1%
% of total	0.0%	5.1%	5.1%
CTC Veridex 11 count	0	1	1
% within CTC Veridex	0.0%	100.0%	100.0%
% within CTC AdnaTest	0.0%	3.1%	2.6%
% of total	0.0%	2.6%	2.6%
Total count	7	32	39
% within CTC Veridex	17.9%	82.1%	100.0%
% within CTC AdnaTest	100.0%	100.0%	100.0%
% of total	17.9%	82.1%	100.0%

Table 2. Correlation between KRAS mutational status in tumor tissues and CTC

	KRAS CTC wild-type mutated		Total
KRAS tissue wild-type count	13	4	17
% within KRAS tissue	76.5%	23.5%	100.0%
% within KRAS tissue	54.2%	66.7%	56.7%
% of total	43.3%	13.3%	56.7%
Mutated count	11	2	13
% within KRAS tissue	84.6%	15.4%	100%
% within KRAS tissue	45.8%	33.3%	43.3%
% of total	36.7%	6.7%	43.3%
Total count	24	6	30
% within KRAS tissue	80.0%	20.0%	100.0%
% within KRAS tissue	100.0%	100.0%	100.0%
% of total	80.0%	20.0%	100.0%

Table 3. Correlation between KRAS overexpression and KRAS mutation in CTC

			KRAS overexpression CTC		Total
			Negative	Positive
KRAS overexpression CTC	Negative	Count	12	6	18
		% within KRAS overexpression CTC	66.7%	33.3%	100.0%
		% within K-RAS CTC	48.0%	85.7%	56.2%
		% of total	37.5%	18.8%	56.2%
	Positive	Count	13	1	14
		% within KRAS overexpression CTC	92.9%	7.1%	100.0%
		% within KRAS CTC	52.0%	14.3%	43.8%
		% of total	40.6%	3.1%	43.8%
Total		Count	25	7	32
		% within KRAS overexpression CTC	78.1%	21.9%	100.0%
		% within KRAS CTC	100.0%	100.0%	100.0%
		% of total	78.1%	21.9%	100.0%

Table 4. Correlation between KRAS mutation/KRAS overexpression and EGFR expression in CTC

			KRAS CTC		Total
			Wild type	Mutated
EGFR CTC	Negative	Count	7	1	8
		% within EGFR CTC	87.5%	12.5%	100.0%
		% within KRAS CTC	28.0%	14.3%	25.0%
		% of total	21.9%	3.1%	25.0%
	Positive	Count	18	6	24
		% within EGFR CTC	75.0%	25.0%	100.0%
		% within KRAS CTC	72.0%	85.7%	75.0%
		% of total	56.2%	18.8%	75.0%
Total		Count	25	7	32
		% within EGFR CTC	78.1%	21.9%	100.0%
		% within KRAS CTC	100.0%	100.0%	100.0%
		% of total	78.1%	21.9%	100.0%
			K-RAS CTC		Total
			Negative	Positive
EGFR CTC	Negative	Count	3	5	8
		% within EGFR CTC	37.5%	62.5%	100.0%
		% within KRAS overexpression CTC	16.7%	35.7%	25.0%
		% of total	9.4%	15.6%	25.0%
	Positive	Count	15	9	24
		% within EGFR CTC	62.5%	37.5%	100.0%
		% within KRAS overexpression CTC	83.3%	64.3%	75.0%
		% of total	46.9%	28.1%	75.0%
Total		Count	18	14	32
		% within EGFR CTC	56.2%	43.8%	100.0%
		% within KRAS overexpression CTC	100.0%	100.0%	100.0%
		% of total	56.2%	43.8%	100.0%

Table 5. Correlation between KRAS mutation in tissue samples and KRAS overexpression in CTC

			KRAS overexpression CTC		Total
			Negative	Positive
K-RAS tissue	Wild type	Count	10	10	20
		% within KRAS tissue	50.0%	50.0%	100.0%
		% within KRAS overexpression CTC	47.6%	62.5%	54.1%
		% of total	27.0%	27.0%	25.0%
	Mutated	Count	11	6	17
		% within KRAS tissue	64.7%	35.3%	100.0%
		% within KRAS overexpression CTC	52.4%	37.5%	45.9%
		% of total	29.7%	16.2%	45.9%
Total		Count	21	6	37
		% within KRAS tissue	56.8%	43.2%	100.0%
		% within KRAS overexpression CTC	100.0%	100.0%	100.0%
		% of total	56.8%	43.2%	100.0%

Table 6. Patient’s characteristics

Patient’s characteristics	N (%)
Age
Range	45–83
Median	63.92
Gender
Male	25/40 (62.5)
Female	15/40 (37.5)
Therapy
Bevacizumab	25/40 (65)
Cetuximab	9/40 (25)
No therapy	6/40 (10)
Line of therapy
First	20/34 (59)
Second	10/34 (29)
Third	4/34 (12)

Figure 2. KRAS expression profile in a cohort of 24 CRC patients initially detected to be CTC positive based on the AdnaTest ColonCancer.