Cryopreservation for delayed circulating tumor cell isolation is a valid strategy for prognostic association of circulating tumor cells in gastroesophageal cancer

Table 1 Characteristics of patients in cohort 2 n (%)

		CTC count
	All patients	Low (CTC ≤ 17)	High (CTC > 17)
	n = 43	n = 23	n = 20
Age
Mean (range)	64 (39-89)	65 (39-89)	64 (48-83)
Sex
Male	32 (74.4)	15 (65.2)	20 (85.0)
Female	11 (25.6)	8 (34.8)	3 (15.0)
ECOG
0-1	36 (83.7)	22 (95.6)	14 (70.0)
2-4	7 (16.3)	1 (4.3)	6 (30.0)
Primary tumor location
Distal oesophageal	12 (27.9)	8 (34.8)	4 (20.0)
Gastroesophageal junction	14 (32.6)	4 (17.4)	10 (50.0)
Gastric	17 (37.5)	11 (47.8)	6 (30.0)
Stage
II	18 (41.9)	13 (56.5)	5 (25.0)
III	6 (14.0)	4 (17.4)	2 (10.0)
IV	19 (44.2)	6 (26.1)	13 (65.0)

CTC: Circulating tumor cell; ECOG: Eastern cooperative oncology group performance status.

Table 2 Univariate and multivariate analysis for overall survival for cohort 2 (n = 43)

	Univariate		Multivariate
Factor	HR (95%CI)	P value	HR (95%CI)	P value
CTC count (high vs low)	4.4 (1.7-11.7)	0.001	3.7 (1.2-12.4)	0.03
Age (≥ 65 vs <65 yr old)	0.7 (0.3-1.8)	0.46	1.0 (0.9-1.1)	0.76
ECOG (2-4 vs 0-1)	7.2 (2.2-23.7)	0.0002	2.3 (0.5-10.1)	0.14
Sex (male vs female)	1.2 (0.4-3.8)	0.7	0.7 (0.2-2.1)	0.49
Stage (IV vs II-III)	10.0 (3.3-30.8)	< 0.0001	9.9 (2.9-33.8)	0.0003
Primary tumor location (gastric vs oesophageal/GOJ)	0.3 (0.1-1.01)	0.05	0.4 (0.2-1.6)	0.22

Significant values are italicised. In both univariate and multivariate analysis, a high CTC count (> 17) remained statistically significant as an independent factor associated with poorer overall survival. CTC: Circulating tumor cell; ECOG: Eastern cooperative oncology group performance status; GOJ: Gastroesophageal junction.