High patatin like phospholipase domain containing 8 expression as a biomarker for poor prognosis of colorectal cancer

Table 1 Clinicopathologic characteristics of the colorectal cancer patients in this study

Clinicopathologic parameters	n	Percentage (%)
All patients	751	100.0
Age in yr
≤ 60	348	46.3
> 60	403	53.7
Sex
Male	453	60.3
Female	298	39.7
CEA in ng/mL
≤ 5	396	52.7
> 5	355	47.3
CA199 in U/mL
≤ 37	607	80.8
> 37	144	19.2
Tumor location
Right-sided colon	209	27.8
Left-sided colon	200	26.6
Rectum	342	45.6
Tumor size in cm
≤ 4.0	428	57.0
> 4.0	323	43.0
Primary histological type
Non-mucinous	640	85.2
Mucinous	111	14.8
Primary differentiation
Well/moderate	497	66.2
Poor/anaplastic	254	33.8
T stage
T1	24	3.2
T2	132	17.6
T3	354	47.1
T4	241	32.1
N stage
N0	410	54.6
N1	231	30.8
N2	110	14.6
Vascular invasion
No	655	87.2
Yes	96	12.8
Nerve invasion
No	695	92.5
Yes	56	7.5
M stage
M0	554	73.8
M1	197	26.2

CA199: Carbohydrate antigen 19-9; CEA: Carcinoembryonic antigen; M: Presence of metastasis; N: Extent of tumor spread to the lymph nodes; T: Extent of the tumor (the size of the tumor and any spread of tumor into nearby tissue).

Table 2 Correlations between patatin like phospholipase domain containing 8 expression and clinicopathological parameters of colorectal cancer patients in this study

Variables	PNPLA8 expression		P value
	Low (%)	High (%)
All patients	331	420
Age in yr			0.811
≤ 60	155 (46.8)	193 (46.0)
> 60	176 (53.2)	227 (54.0)
Sex			0.375
Male	199 (60.1)	239 (56.9)
Female	132 (39.9)	181 (43.1)
CEA in ng/mL			0.821
≤ 5	173 (52.3)	223 (53.1)
> 5	158 (47.7)	197 (46.9)
CA199 in U/mL			0.900
≤ 37	267 (80.7)	340 (81.0)
> 37	64 (19.3)	80 (19.0)
Tumor location			0.434
Right-sided colon	97 (29.3)	112 (26.7)
Left-sided colon	92 (27.8)	108 (25.7)
Rectum	142 (42.9)	200 (47.6)
Tumor size in cm			0.589
≤ 4.0	185 (55.9)	243 (57.9)
> 4.0	146 (44.1)	177 (42.1)
Primary histological type			0.848
Non-mucinous	283 (85.5)	357 (85.0)
Mucinous	48 (14.5)	63 (15.0)
Primary differentiation			0.160
Well/moderate	210 (63.4)	287 (68.3)
Poor/anaplastic	121 (36.6)	133 (31.7)
T stage			0.618
T1/T2	66 (19.9)	90 (21.4)
T3/T4	265 (80.1)	330 (78.6)
N stage			0.684
N0	180 (54.4)	230 (54.8)
N1	106 (32.0)	125 (29.8)
N2	45 (13.6)	65 (15.4)
Vascular invasion			0.710
No	287 (86.7)	368 (87.6)
Yes	44 (13.3)	52 (12.4)
Nerve invasion			0.638
No	308 (93.1)	387 (92.1)
Yes	23 (6.9)	33 (7.9)
M stage			0.048
M0	256 (77.3)	298 (71.0)
M1	75 (22.7)	122 (29.0)

CA199: Carbohydrate antigen 19-9; CEA: Carcinoembryonic antigen; PNPLA8: Patatin like phospholipase domain containing 8; M: Presence of metastasis; N: Extent of tumor spread to the lymph nodes; T: Extent of the tumor (the size of the tumor and any spread of tumor into nearby tissue).

Table 3 Cox regression analyses for overall survival of colorectal cancer patients in this study

Variates	Overall survival
	Univariate analysis		Multivariate analysis
	HR (95%CI)	P value	HR (95%CI)	P value
PNPLA8		0.004		0.038
Low	1 (reference)		1 (reference)
High	1.472 (1.132-1.914)		1.328 (1.016-1.734)
Age in yr		0.561
≤ 60	1 (reference)
> 60	1.079 (0.835-1.394)
Sex		0.087		0.903
Male	1 (reference)		1 (reference)
Female	0.792(0.606-1.304)		0.903 (0.687-1.187)
CEA in ng/mL		< 0.001		0.811
≤ 5	1 (reference)		1 (reference)
> 5	2.126(1.636-2.763)		0.964 (0.715-1.300)
CA199 in U/mL		< 0.001		0.004
≤ 37	1 (reference)		1 (reference)
> 37	2.870 (2.191-3.759)		1.548 (1.150-2.083)
Tumor location		0.050		0.895
Right-sided colon	1 (reference)		1 (reference)
Left-sided colon	0.952 (0.687-1.320)		0.933 (0.667-1.305)
Rectum	0.706 (0.518-0.962)		0.934 (0.680-1.284)
Tumor size in cm		0.512
≤ 4.0	1 (reference)
> 4.0	1.090 (0.843-1.409)
Primary histological type		0.371
Non-mucinous	1 (reference)
Mucinous	0.854 (0.603-1.208)
Primary differentiation		0.002		0.162
Well/moderate	1 (reference)		1 (reference)
Poor/anaplastic	1.507 (1.162-1.954)		1.210 (0.926-1.581)
T stage		< 0.001		0.163
T1/T2	1 (reference)		1 (reference)
T3/T4	3.058 (1.934-4.834)		1.415 (0.869-2.306)
N stage		< 0.001		< 0.001
N0	1 (reference)		1 (reference)
N1/N2	2.948 (2.852-3.859)		1.701 (1.272-2.274)
M stage		< 0.001		< 0.001
M0	1 (reference)		1 (reference)
M1	7.193 (5.520-9.372)		4.862 (3.608-6.551)
Vascular invasion		< 0.001		0.017
No	1 (reference)		1 (reference)
Yes	2.265 (1.649-3.111)		1.512 (1.078-2.121)
Nerve invasion		< 0.001		0.218
No	1 (reference)		1 (reference)
Yes	2.901 (1.986-4.236)		1.291 (0.860-1.939)

CA199: Carbohydrate antigen 19-9; CEA: Carcinoembryonic antigen; HR: Hazard ratio; M: Presence of metastasis; N: Extent of tumor spread to the lymph nodes; PNPLA8: Patatin like phospholipase domain containing 8; T: Extent of the tumor (the size of the tumor and any spread of tumor into nearby tissue).