Functionality is not an independent prognostic factor for pancreatic neuroendocrine tumors

Table 1 Characteristics of patients in the two databases, n (%)

Database	SEER database (n = 426)	West China Hospital database (n = 205)	P value
Race			NC
White	357 (83.8)	0 (0.0)
Asian1	25 (5.9)	205 (100)
Others2	44 (10.3)	0 (0.0)
Tumor site			< 0.001
Head	104 (24.4)	85 (41.5)
Body	51 (12)	55 (26.8)
Tail	168 (39.4)	44 (21.5)
Unknown	103 (24.2)	21 (10.2)
Age (yr)			< 0.001
0-55	193 (45.3)	138 (67.3)
56-	233 (54.7)	67 (32.7)
Sex			0.035
Male	221 (51.9)	88 (42.9)
Female	205 (48.1)	117 (57.1)
Primary tumor			0.0303
T1	121 (28.4)	80 (39)
T2	135 (31.7)	72 (35.1)
T3	94 (22.1)	44 (21.5)
T4	41 (9.6)	9 (4.4)
Tx	35 (8.2)	0 (0)
Regional lymph node metastasis			0.1713
N0	188 (44.1)	41 (20)
N1	149 (35)	22 (10.7)
Nx	89 (20.9)	142 (69.3)
Distant metastasis			0.0443
M0	143 (33.6)	193 (94.1)
M1	19 (4.5)	12 (5.9)
Mx	264 (62)	0 (0)
Grade			< 0.0013
pNET G1	229 (53.8)	90 (43.9)
pNET G2	45 (10.6)	96 (46.8)
pNET G3 or pNEC	16 (3.8)	9 (4.4)
Gx	136 (31.9)	10 (4.9)
Functionality			< 0.001
N	326 (76.5)	101 (49.3)
I	52 (12.2)	85 (41.5)
O	48 (11.3)	19 (9.3)
Surgery			< 0.0013
Pancreaticoduodenectomy	143 (33.6)	39 (19)
Total pancreatectomy	39 (9.2)	6 (2.9)
Partial pancreatectomy	203 (47.7)	88 (42.9)
Local excision	38 (8.9)	72 (35.1)
Other surgeries	3 (0.7)	0 (0)

¹Consisting of Asian and Pacific Islander patients.

²Consisting of Black and American Indian patients and patients whose races were unknown.

³Rows with the title Tx, Nx, Mx, Gx, and other surgeries were not involved in the χ² test. SEER: Surveillance, epidemiology, and end results; NC: Not comparable; pNET: Pancreatic neuroendocrine tumor; pNEC: Pancreatic neuroendocrine carcinoma; I: Insulinoma; N: Nonfunctional pNEN; O: Other functional pNEN.

Table 2 Characteristics of patients of different races, n (%)

Race	White (n = 357)	Asian1 (n = 230)	Others2 (n = 44)	P value
Tumor site				< 0.001
Head	80 (22.4)	94 (40.9)	15 (34.1)
Body	40 (11.2)	59 (25.7)	7 (15.9)
Tail	153 (42.9)	48 (20.9)	11 (25)
Unknown	84 (23.5)	29 (12.6)	11 (25)
Age (yr)				< 0.001
0-55	156 (43.7)	150 (65.2)	25 (56.8)
56-	201 (56.3)	80 (34.8)	19 (43.2)
Sex				0.002
Male	162 (45.4)	130 (56.5)	30 (68.2)
Female	195 (54.6)	100 (43.5)	14 (31.8)
Primary tumor				0.0733
T1	98 (27.5)	89 (38.7)	14 (31.8)
T2	117 (32.8)	79 (34.3)	11 (25)
T3	79 (22.1)	51 (22.2)	8 (18.2)
T4	35 (9.8)	10 (4.3)	5 (11.4)
Tx	28 (7.8)	1 (0.4)	6 (13.6)
Regional lymph node metastasis				0.0943
N0	157 (44)	53 (23)	19 (43.2)
N1	128 (35.9)	25 (10.9)	18 (40.9)
Nx	72 (20.2)	152 (66.1)	7 (15.9)
Distant metastasis				0.0543
M0	119 (33.3)	202 (87.8)	15 (34.1)
M1	16 (4.5)	12 (5.2)	3 (6.8)
Mx	222 (62.2)	16 (7)	26 (59.1)
Grade				< 0.0013
pNET G1	192 (53.8)	105 (45.7)	22 (50)
pNET G2	42 (11.8)	98 (42.6)	1 (2.3)
pNET G3 or pNEC	13 (3.6)	9 (3.9)	3 (6.8)
Gx	110 (30.8)	18 (7.8)	18 (40.9)
Functionality				< 0.001
N	277 (77.6)	117 (50.9)	33 (75)
I	40 (11.2)	93 (40.4)	4 (9.1)
O	40 (11.2)	20 (8.7)	7 (15.9)
Surgery				< 0.0013
Pancreaticoduodenectomy	111 (31.1)	51 (22.2)	20 (45.5)
Total pancreatectomy	33 (9.2)	7 (3)	5 (11.4)
Partial pancreatectomy	179 (50.1)	96 (41.7)	16 (36.4)
Local excision	31 (8.7)	76 (33)	3 (6.8)
Other surgeries	3 (0.8)	0 (0)	0 (0)

¹Consisting of Asian and Pacific Islander patients.

²Consisting of Black and American Indian patients and patients whose races were unknown.

³Rows with the title Tx, Nx, Mx, Gx and other surgeries were not involved in the chi-square test. pNET: Pancreatic neuroendocrine tumor; pNEC: Pancreatic neuroendocrine carcinoma; I: Insulinoma; N: Nonfunctional pNEN; O: Other functional pNEN.

Table 3 Univariate and multivariate Cox proportional hazard regression analyses of predictors of survival in patients

Study population		SEER database		West China Hospital database			All population
Variables		HR (95CI)	P value	HR (95%CI)		P value	HR (95%CI)		P value
Univariate analysis
Country
United States							1.000
China							0.326	(0.159, 0.665)	0.002
Race
White	1.000						1.000
Asian	0.402	(0.098, 1.652)	0.206				0.326	(0.169, 0.626)	0.001
Age (yr)
Below 55	1.000			1.000			1.000
Over 56	2.121	(1.204, 3.738)	0.009	4.224	(1.055, 16.919)	0.042	2.710	(1.606, 4.574)	< 0.001
Sex
Female	1.000			1.000			1.000
Male	1.822	(1.065, 3.119)	0.029	4.262	(0.878, 20.686)	0.072	2.067	(1.251, 3.415)	0.005
Primary site
Head	1.000			1.000			1.000
Body	2.077	(0.899, 4.800)	0.087	0.801	(0.146, 4.398)	0.799	1.651	(0.784, 3.479)	0.187
Tail	1.259	(0.616, 2.573)	0.527	1.193	(0.266, 5.349)	0.817	1.445	(0.769, 2.718)	0.253
Unknown	1.359	(0.598, 3.085)	0.464	0.000		0.987	1.491	(0.698, 3.187)	0.303
Primary tumor
T1-2	1.000			1.000			1.000
T3-4	2.515	(1.490, 4.246)	0.001	3.663	(0.980, 13.688)	0.054	2.858	(1.756, 4.651)	< 0.001
Regional lymph node metastasis
N0	1.000			1.000			1.000
N1	1.602	(0.918, 2.795)	0.097	2.757	(0.387, 19.630)	0.311	1.775	(1.040, 3.032)	0.036
Nx	0.911	(0.407, 2.038)	0.820	0.981	(0.186, 5.170)	0.982	0.585	(0.293, 1.167)	0.128
Distant metastasis
M0	1.000			1.000			1.000
M1	5.295	(1.804, 15.543)	0.002	3.423	(0.423, 27.705)	0.249	5.726	(2.269, 14.450)	< 0.001
Mx	1.993	(0.973, 4.079)	0.059				2.773	(1.551, 4.960)	0.001
Grade
G1	1.000			1.000			1.000
G2	1.418	(0.734, 2.739)	0.298	9.823	(1.224, 78.806)	0.032	1.266	(0.740, 2.166)	0.388
Functionality
I	1.000			1.000			1.000
N	1.924	(0.691, 5.353)	0.210	1.473	(0.268, 8.092)	0.656	2.544	(1.090, 5.938)	0.031
O	2.247	(0.600, 8.423)	0.230	7.913	(1.314, 47.670)	0.024	3.925	(1.359, 11.337)	0.012
Multivariate analysis
Race
White							1.000
Asian							0.438	(0.225, 0.851)	0.015
Age
Below 55	1.000			1.000			1.000
Over 56	2.203	(1.249, 3.884)	0.006	4.558	(1.122, 18.521)	0.034	2.315	(1.362, 3.935)	0.002
Sex
Female				1.000			1.000
Male				5.707	(1.161, 28.057)	0.032	1.744	(1.049, 2.899)	0.032
Primary tumor
T1-2	1.000						1.000
T3-4	2.589	(1.533, 4.371)	< 0.001				2.612	(1.603, 4.254)	< 0.001
Grade
G1				1.000
G2				9.039	(1.118, 73.051)	0.039

SEER: Surveillance, epidemiology, and end results; I: Insulinoma; N: Nonfunctional pNEN; O: Other functional pNEN.