Nomogram using F-18 fluorodeoxyglucose positron emission tomography/computed tomography for preoperative prediction of lymph node metastasis in gastric cancer

Table 1 Patient characteristics

	Training cohort			Validation cohort
Variables	LN metastasis (-)	LN metastasis (+)	P value	LN metastasis (-)	LN metastasis (+)	P value
	(n = 206)	(n = 171)		(n = 128)	(n = 61)
Age	59.2 ± 11.5	59.6 ± 12.1	0.701	59.5 ± 12.1	61.8 ± 12.8	0.218
Sex			0.577			0.456
Male	122 (59.2%)	107 (62.6%)		73 (57.0%)	39 (63.9%)
Female	84 (40.8%)	64 (37.4%)		55 (43.0%)	22 (36.1%)
Tumor Location			< 0.001			0.034
Upper	46 (22.3%)	27 (15.8%)		25 (19.5%)	15 (24.6%)
Middle	32 (15.5%)	35 (20.5%)		24 (18.8%)	11 (18.0%)
Low	122 (59.2%)	81 (47.4%)		78 (60.9%)	30 (49.2%)
Mixed	6 (2.9%)	28 (16.4%)		1 ( 0.8%)	5 (8.2%)
Pathologic T stage			< 0.001			< 0.001
1	158 (76.7%)	28 (16.4%)		100 (78.1%)	10 (16.4%)
2	20 (9.7%)	27 (15.8%)		11 (8.6%)	12 (19.7%)
3	18 (8.7%)	27 (15.8%)		8 (6.2%)	18 (29.5%)
4	10 (4.9%)	89 (52.0%)		9 (7.0%)	21 (34.4%)
WBC counts (103 cells/μL)	6.4 ± 1.8	6.2 ± 1.7	0.283	6.2 ± 1.6	6.5 ± 1.8	0.295
Blood hemoglobin levels (g/dL)	12.5 ± 1.6	12.0 ± 1.8	0.004	13.3 ± 9.7	12.2 ± 2.1	0.211
Platelet counts (103 cells/μL)	267.2 ± 72.6	287.9 ± 91.0	0.017	267.3 ± 74.4	282.0 ± 67.3	0.192
Neutrophil counts (cells/μL)	3777.4 ± 1458.7	3810.9 ± 1333.2	0.818	3686.8 ± 1367.7	3902.9 ± 1405.2	0.315
Lymphocyte counts (cells/μL)	1860.3 ± 609.4	1661.1 ± 589.8	0.001	1835.0 ± 521.7	1855.1 ± 764.4	0.853
PLR	159.3 ± 72.8	196.4 ± 98.8	< 0.001	155.3 ± 60.3	184.8 ± 111.5	0.057
NLR	2.3 ± 1.4	2.5 ± 1.2	0.036	2.2 ± 1.2	2.6 ± 2.0	0.136
CEA (ng/mL)	4.8 ± 25.9	7.9 ± 27.9	0.268	2.6 ± 3.5	3.7 ± 6.1	0.195
CA 19-9 (U/mL)	18.1 ± 62.7	96.0 ± 364.9	0.006	10.0 ± 7.6	12.7 ± 8.6	0.029
Albumin (g/dL)	4.1 ± 0.3	3.9 ± 0.4	< 0.001	4.0 ± 0.3	3.9 ± 0.4	0.032
T_SUVmax	2.9 ± 4.4	6.1 ± 5.5	< 0.001	2.2 ± 3.7	6.9 ± 6.7	< 0.001
N_SUVmax	0.1 ± 0.9	1.8 ± 3.7	< 0.001	0.1 ± 0.5	1.7 ± 3.9	0.002

LN: Lymph node; WBC: White blood cell; PLR: Platelet to lymphocyte ratio; NLR: Neutrophil to lymphocyte ratio; CEA: Carcinoembryonic Antigen; CA 19-9: Carbohydrate antigen 19-9; SUVmax: Maximum standardized uptake value; T_SUVmax: SUVmax of primary tumor; N_SUVmax: SUVmax of LN.

Table 2 Uni- and multivariate logistic regression analyses for regional lymph node metastases in the training cohort

	Univariate logistic analysis		Multivariate logistic analysis
Variables	OR (95%CI)	P value	OR (95%CI)	P value
Age, yr	1.00 (0.99–1.02)	0.700
Sex (male vs female)	0.87 (0.57–1.32)	0.507
Tumor location	1.31 (1.04–1.65)	0.022	1.19 (0.92–1.55)	0.178
WBC counts	0.94 (0.83–1.05)	0.283
Blood hemoglobin levels	0.84 (0.74–0.94)	0.005	1.07 (0.91–1.26)	0.433
Platelet counts	1.00 (1.00–1.01)	0.016	1.00 (1.00–1.01)	0.625
Neutrophil counts	1.00 (1.00–1.00)	0.817
Lymphocyte counts	1.00 (1.00–1.00)	0.002	1.00 (1.00–1.00)	0.342
PLR	1.01 (1.00–1.01)	< 0.001	1.00 (0.99–1.01)	0.816
NLR	1.19 (1.01–1.41)	0.041	0.85 (0.65–1.10)	0.234
CEA	1.00 (1.00–1.01)	0.290
CA 19-9	1.00 (1.00–1.01)	0.018	1.00 (1.00–1.01)	0.133
Albumin	0.26 (0.13–0.49)	< 0.001	0.52 (0.23–1.15)	0.110
T_SUVmax	1.17 (1.11–1.24)	< 0.001	1.08 (1.02–1.15)	0.011
N_SUVmax	1.81 (1.45–2.40)	< 0.001	1.49 (1.19–1.97)	0.002

WBC: White blood cell; PLR: Platelet to lymphocyte ratio; NLR: Neutrophil to lymphocyte ratio; CEA: Carcinoembryonic Antigen; CA 19-9: Carbohydrate antigen 19-9; SUVmax: Maximum standardized uptake value; T_SUVmax: SUVmax of primary tumor; N_SUVmax: SUVmax of LN.

Table 3 Uni- and multivariate logistic regression analyses for regional lymph node metastases in the test cohort

	Univariate Logistic Analysis		Multivariate Logistic Analysis
Variables	OR (95%CI)	P value	OR (95%CI)	P value
Age, yr	1.02 (0.99–1.04)	0.218
Sex (male vs female)	0.75 (0.40–1.40)	0.367
Tumor location	0.97 (0.68–1.40)	0.881
WBC counts	1.10 (0.92–1.33)	0.295
Blood hemoglobin levels	0.95 (0.82–1.02)	0.451
Platelet counts	1.00 (1.00–1.01)	0.194
Neutrophil counts	1.00 (1.00–1.00)	0.315
Lymphocyte counts	1.00 (1.00–1.00)	0.832
PLR	1.00 (1.00–1.01)	0.027	1.00 (0.99–1.00)	0.632
NLR	1.19 (0.98–1.46)	0.087
CEA	1.05 (0.99–1.13)	0.138
CA 19-9	1.04 (1.00–1.08)	0.032	1.03 (0.99–1.07)	0.185
Albumin	0.31 (0.12–0.80)	0.017	1.00 (0.30–3.32)	0.994
T_SUVmax	1.23 (1.14–1.34)	< 0.001	1.17 (1.07–1.29)	< 0.001
N_SUVmax	2.02 (1.43–3.29)	< 0.001	1.60 (1.09–2.69)	0.038

WBC: White blood cell; PLR: Platelet to lymphocyte ratio; NLR: Neutrophil to lymphocyte ratio; CEA: Carcinoembryonic Antigen; CA 19-9: Carbohydrate antigen 19-9; SUVmax: Maximum standardized uptake value; T_SUVmax: SUVmax of primary tumor; N_SUVmax: SUVmax of LN.