Risk stratification in gastric cancer lung metastasis: Utilizing an overall survival nomogram and comparing it with previous staging

Table 1 Comparison of clinical features between the training and validation sets in the overall survival group, n (%)

Variable	Total (n = 1652)	Train set (n = 1156)	Valid set (n = 496)	Statistic	P value
Months from diagnosis to treatment, M (Q1, Q3)	1.00 (1.00 - 1.00)	1.00 (1.00 - 1.00)	1.00 (1.00 - 1.00)	Z = 1.394	0.252
Tumor size				χ2 = 1.983	0.371
≤ 5	421 (25.48)	302 (26.12)	119 (23.99)
5-10	1159 (70.16)	800 (69.20)	359 (72.38)
≥ 10	72 (4.36)	54 (4.67)	18 (3.63)
Age				χ2 = 0.077	0.782
< 60	505 (30.57)	351 (30.36)	154 (31.05)
≥ 60	1147 (69.43)	805 (69.64)	342 (68.95)
Race				χ2 = 1.121	0.571
Black	190 (11.5)	127 (10.99)	63 (12.70)
Other	199 (12.05)	138 (11.94)	61 (12.30)
White	1263 (76.45)	891 (77.08)	372 (75.00)
Sex				χ2 = 1.552	0.213
Female	529 (32.02)	381 (32.96)	148 (29.84)
Male	1123 (67.98)	775 (67.04)	348 (70.16)
Primary site				χ2 = 3.797	0.803
Antrum	165 (9.99)	119 (10.29)	46 (9.27)
Body	116 (7.02)	78 (6.75)	38 (7.66)
Cardia	713 (43.16)	494 (42.73)	219 (44.15)
Fundus	91 (5.51)	62 (5.36)	29 (5.85)
Greater curvature	48 (2.91)	34 (2.94)	14 (2.82)
Lesser curvature	75 (4.54)	48 (4.15)	27 (5.44)
Others	426 (25.79)	309 (26.73)	117 (23.59)
Pylorus	18 (1.09)	12 (1.04)	6 (1.21)
Histologic				χ2 = 6.574	0.037a
Adenocarcinoma	1039 (62.89)	704 (60.90)	335 (67.54)
Others	372 (22.52)	275 (23.79)	97 (19.56)
Signet ring cell carcinoma	241 (14.59)	177 (15.31)	64 (12.90)
Surgery				χ2 = 1.650	0.199
No	1579 (95.58)	1100 (95.16)	479 (96.57)
Yes	73 (4.42)	56 (4.84)	17 (3.43)
Regional lymph node surgery				χ2 = 1.063	0.302
No	1568 (94.92)	1093 (94.55)	475 (95.77)
Yes	84 (5.08)	63 (5.45)	21 (4.23)
Surgery other regional/distant				χ2 = 0.001	0.976
No	1575 (95.34)	1102 (95.33)	473 (95.36)
Yes	77 (4.66)	54 (4.67)	23 (4.64)
Treatment sequence				-	0.057
No radiation and/or cancer-directed surgery	1616 (97.82)	1126 (97.40)	490 (98.79)
Radiation after surgery	24 (1.45)	22 (1.90)	2 (0.40)
Radiation before and after surgery	1 (0.06)	1 (0.09)	0 (0.00)
Radiation prior to surgery	11 (0.67)	7 (0.61)	4 (0.81)
Radiation				χ2 = 0.380	0.537
No	1344 (81.36)	936 (80.97)	408 (82.26)
Yes	308 (18.64)	220 (19.03)	88 (17.74)
Chemotherapy				χ2 = 0.601	0.438
No	740 (44.79)	525 (45.42)	215 (43.35)
Yes	912 (55.21)	631 (54.58)	281 (56.65)
Nodes positive				χ2 = 5.288	0.021
< 4	60 (3.63)	50 (4.33)	10 (2.02)
≥ 4	1592 (96.37)	1106 (95.67)	486 (97.98)
Metastases at bone				χ2 = 2.578	0.108
No	1305 (79)	901 (77.94)	404 (81.45)
Yes	347 (21)	255 (22.06)	92 (18.55)
Metastases at brain				χ2 = 3.751	0.053
No	1581 (95.7)	1099 (95.07)	482 (97.18)
Yes	71 (4.3)	57 (4.93)	14 (2.82)
Metastases at liver				χ2 = 2.773	0.096
No	781 (47.28)	562 (48.62)	219 (44.15)
Yes	871 (52.72)	594 (51.38)	277 (55.85)
Marital status at diagnosis				χ2 = 0.216	0.642
0	990 (59.93)	697 (60.29)	293 (59.07)
1	662 (40.07)	459 (39.71)	203 (40.93)
T stage				χ2 = 3.078	0.688
T0	10 (0.61)	5 (0.43)	5 (1.01)
T1	327 (19.79)	227 (19.64)	100 (20.16)
T2	62 (3.75)	42 (3.63)	20 (4.03)
T3	180 (10.9)	132 (11.42)	48 (9.68)
T4	285 (17.25)	200 (17.30)	85 (17.14)
TX	788 (47.7)	550 (47.58)	238 (47.98)
N stage				χ2 = 0.708	0.950
N0	588 (35.59)	408 (35.29)	180 (36.29)
N1	626 (37.89)	440 (38.06)	186 (37.50)
N2	59 (3.57)	43 (3.72)	16 (3.23)
N3	63 (3.81)	46 (3.98)	17 (3.43)
NX	316 (19.13)	219 (18.94)	97 (19.56)

^aP < 0.05.

M: Median.

Table 2 Univariate and multivariate analysis of gastric cancer overall survival

Variables	Beta	SE	Z	P value	HR (95%CI)	m_Beta	m_SE	m_Z	P value	HR (95%CI)
Months from diagnosis to treatment	-0.15	0.03	-4.90	< 0.001a	0.86 (0.81-0.92)	-0.15	0.04	-4.11	< 0.001b	0.86 (0.80-0.93)
Tumor size
≤ 5					Ref.
5-10	0.13	0.07	1.96	0.05a	1.14 (1.01-1.31)
≥ 10	0.08	0.15	0.53	0.593	1.08 (0.81-1.45)
Age
2					Ref.
1	-0.10	0.07	-1.52	0.127	0.91 (0.80-1.03)
Race
White					Ref.
Other	0.19	0.09	1.99	0.047a	1.20 (1.01-1.45)
Black	0.14	0.10	1.42	0.154	1.15 (0.95-1.39)
Sex
Female					Ref.
Male	0.03	0.06	0.42	0.677	1.03 (0.91-1.16)
Primary site
Antrum					Ref.					Ref.
Others	0.19	0.11	1.72	0.085a	1.21 (0.97-1.50)	0.24	0.11	2.10	0.036b	1.26 (1.02-1.58)
Cardia	-0.06	0.10	-0.54	0.591	0.95 (0.77-1.16)	0.13	0.11	1.22	0.222	1.14 (0.92-1.41)
Body	0.14	0.15	0.97	0.331	1.16 (0.86-1.55)	0.41	0.15	2.73	0.006b	1.51 (1.12-2.04)
Pylorus	0.03	0.30	0.09	0.928	1.03 (0.57-1.86)	0.44	0.31	1.42	0.154	1.55 (0.85-2.85)
Fundus	0.19	0.16	1.19	0.234	1.21 (0.88-1.65)	0.12	0.16	0.77	0.442	1.13 (0.83-1.55)
Lesser curvature	0.10	0.17	0.57	0.571	1.10 (0.79-1.55)	0.28	0.18	1.61	0.107	1.33 (0.94-1.88)
Greater curvature	0.50	0.20	2.57	0.010a	1.66 (1.13-2.43)	0.72	0.20	3.61	< 0.001b	2.05 (1.39-3.02)
Histologic
Signet ring cell carcinoma					Ref.
Adenocarcinoma	-0.14	0.09	-1.62	0.106	0.87 (0.74-1.03)
Others	-0.11	0.10	-1.15	0.250	0.89 (0.74-1.08)
Surgery
No					Ref.					Ref.
Yes	-0.50	0.14	-3.54	< 0.001a	0.60 (0.46-0.80)	-0.83	0.17	-4.77	< 0.001b	0.43 (0.31-0.61)
Regional lymph node surgery
No					Ref.
Yes	-0.44	0.13	-3.31	< 0.001a	0.64 (0.50-0.84)
Treatment sequence
No radiation and/or cancer-directed surgery					Ref.					Ref.
Radiation prior to surgery	-0.44	0.38	-1.17	0.243	0.64 (0.31-1.35)	0.89	0.44	2.00	0.045b	2.43 (1.02-5.78)
Radiation after surgery	-0.78	0.23	-3.44	< 0.001a	0.46 (0.29-0.72)	-0.21	0.25	-0.84	0.400	0.81 (0.49-1.33)
Radiation before and after surgery	0.33	1.00	0.33	0.742	1.39 (0.20-9.89)	1.60	1.02	1.58	0.115	4.98 (0.68-36.63)
Surgery other regional distance
No					Ref.					Ref.
Yes	-0.53	0.14	-3.74	< 0.001a	0.59 (0.44-0.78)	-0.32	0.16	-1.95	0.051	0.73 (0.53-1.00)
Chemotherapy
Yes					Ref.					Ref.
No	1.21	0.06	19.12	< 0.001a	3.35 (2.96-3.79)	1.29	0.07	19.02	< 0.001b	3.63 (3.18-4.14)
Radiation
No					Ref.					Ref.
Yes	-0.27	0.08	-3.59	< 0.001a	0.76 (0.66-0.88)	-0.17	0.09	-1.99	0.046b	0.84 (0.71-0.99)
Nodes positive
≥ 4					Ref.					Ref.
< 4	-0.38	0.15	-2.56	0.011a	0.68 (0.51-0.91)	0.28	0.18	1.54	0.125	1.32 (0.93-1.89)
Metastases at brain
No					Ref.
Yes	-0.04	0.14	-0.28	0.777	0.96 (0.73-1.26)
Metastases at bone
No					Ref.					Ref.
Yes	0.17	0.07	2.40	0.017a	1.19 (1.03-1.37)	0.28	0.07	3.71	< 0.001b	1.32 (1.14-1.53)
Metastases at liver
No					Ref.					Ref.
Yes	0.22	0.06	3.60	< 0.001a	1.24 (1.10-1.39)	0.26	0.06	4.14	< 0.001b	1.30 (1.15-1.47)
Marital status at diagnosis
1					Ref.
0	-0.20	0.06	-3.19	0.001a	0.82 (0.73-0.93)
T stage
TX					Ref.
T3	-0.24	0.10	-2.40	0.016a	0.79 (0.65-0.96)
T4	0.02	0.08	0.24	0.808	1.02 (0.87-1.20)
T2	-0.20	0.16	-1.21	0.228	0.82 (0.59-1.13)
T1	-0.11	0.08	-1.35	0.177	0.90 (0.77-1.05)
T0	-0.47	0.50	-0.94	0.347	0.62 (0.23-1.67)
N stage
N1					Ref.					Ref.
NX	0.18	0.08	2.09	0.037a	1.19 (1.01-1.40)	0.06	0.09	0.73	0.463	1.07 (0.90-1.26)
N2	0.00	0.16	0.03	0.979	1.00 (0.73-1.37)	0.30	0.17	1.79	0.073	1.35 (0.97-1.86)
N0	0.05	0.07	0.67	0.506	1.05 (0.91-1.20)	-0.03	0.07	-0.38	0.703	0.97 (0.84-1.12)
N3	0.14	0.16	0.91	0.361	1.15 (0.85-1.56)	0.37	0.16	2.36	0.018b	1.45 (1.07-1.98)

^aP < 0.1: Included in the multivariate analysis.

^bP < 0.05: There is a significant difference in the multivariate analysis.

HR: Hazard ratio; T: Tumor; N: Node; m_Beta: Multivariate beta (the coefficient estimate from multivariate analysis); m_SE: Multivariate standard error (the standard error of the multivariate beta coefficient); m_Z: Multivariate Z (the Z-score or Z-statistic associated with the multivariate beta coefficient).