Tumour chemotherapy sensitivity test may predict clinical outcomes in colorectal cancer patients receiving oxaliplatin and fluoropyrimidine-based regimens

Table 1 Characteristics of the patients included in the chemosensitivity assay (n = 1549), n (%)

Characteristics	Value
Sex
Male	909 (58.68)
Female	640 (41.32)
Age, years, mean ± SD	64.01 ± 11.62
Histology
Adenocarcinoma	1539 (99.35)
Neuroendocrine carcinoma	5 (0.32)
Melanoma	2 (0.13)
Small cell carcinoma	1 (0.06)
Squamous carcinoma	1 (0.06)
Adenosquamous carcinoma	1 (0.06)
Sampling position
Colon	884 (57.07)
Rectum	571 (36.86)
Colon + rectum	94 (6.07)
Stage
I	198 (12.78)
II	594 (38.35)
III	693 (44.74)
IV	62 (4.00)
Not confirmed	2 (0.13)

Table 2 Summary of the chemosensitivity to chemotherapy regimens (n = 1549)

Drugs	n	Level of chemosensitivity				Sensitivity rate (%)
		Strong	Partial	Weak	Resistant
5-FU + L-OHP	1474	22	153	1	1298	11.9
5-FU + SN-38	1474	48	217	1	1208	18.0
5-FU	75	1	3	0	71	5.3
L-OHP	75	1	3	0	71	5.3
SN-38	75	2	10	0	63	16.0

Strong sensitivity, IC₉₀ ≤ 100% test drug concentration (TDC) and IC₅₀ ≤ 25% TDC; partial sensitivity, IC₉₀ > 100% TDC and IC₅₀ ≤ 25% TDC; weak sensitivity, IC₉₀ ≤ 100% TDC and IC₅₀ > 25% TDC; resistant, IC₉₀ > 100% TDC and IC₅₀ > 25% TDC. 5-FU: 5-fluorouracil; L-OHP: Oxaliplatin; SN-38: Irinotecan.

Table 3 Patient characteristics in the training set (n = 283), n (%)

Characteristics	Sensitive group (n = 36)	Resistant group (n = 247)	P value
Sex
Male	20 (55.56)	141 (57.09)	0.863
Female	16 (44.44)	106 (42.91)
Age, years
mean ± SD	63.44 ± 8.71	59.33 ± 10.96	0.032a
Histology
Adenocarcinoma	53 (100.00)	352 (100.00)	-
Sampling location
Colon	20 (55.56)	169 (68.42)	0.126
Rectum	16 (44.44)	78 (31.58)
Stage
II	13 (36.11)	85 (34.41)	0.841
III	23 (63.89)	162 (65.59)

^aP < 0.05.

Table 4 Univariate and multivariate Cox proportional hazards regression analyses of the overall survival of patients in the training set

Variables	Univariate analysis		Multivariate analysis
	P value	HR (95%CI)	P value	HR (95%CI)
Age, years	< 0.001c	1.08 (1.04-1.13)	< 0.001c	1.10 (1.05-1.14)
Sex
Male	0.365	1.00 (reference)	-	-
Female		0.72 (0.36-1.46)		-
Sampling position
Colon	0.671	1.00 (reference)	-	-
Rectum		0.85 (0.42-1.76)		-
Stage
II	0.017a	1.00 (reference)	0.019a	1.00 (reference)
III		3.17 (1.23-8.19)		3.13 (1.21-8.10)
ATP-TCA
Sensitive	0.100	1.00 (reference)	0.048a	1.00 (reference)
Resistant		5.31 (0.73-38.85)		7.48 (1.02-55.16)

^aP < 0.05.

^cP < 0.001.

HR: Hazard ratio; CI: Confidence interval; ATP-TCA: Adenosine triphosphate-based tumour chemotherapy sensitivity test.

Table 5 Univariate and multivariate Cox proportional hazards regression analyses of the disease-free survival of patients in the training set

Variables	Univariate analysis		Multivariate analysis
	P value	HR (95%CI)	P value	HR (95%CI)
Age, years	0.012a	1.03 (1.01-1.05)	0.003b	1.04 (1.01-1.06)
Sex
Male	0.700	1.00 (reference)	-	-
Female		0.92 (0.61-1.40)		-
Sampling position
Colon	0.071	1.00 (reference)	0.030a	1.00 (reference)
Rectum		1.47 (0.97-2.22)		1.59 (1.05-2.41)
Stage
II	< 0.001c	1.00 (reference)	< 0.001c	1.00 (reference)
III		2.77 (1.64-4.69)		2.76 (1.63-4.68)
ATP-TCA
Sensitive	0.008b	1.00 (reference)	0.002b	1.00 (reference)
Resistant		3.92 (1.44-10.68)		4.98 (1.81-13.72)

^aP < 0.05.

^bP < 0.01.

^cP < 0.001.

HR: Hazard ratio; CI: Confidence interval; ATP-TCA: Adenosine triphosphate-based tumour chemotherapy sensitivity test.