Effect of prior malignancy on the prognosis of gastric cancer and somatic mutation

Table 1 Baseline characteristics of patients diagnosed with gastric cancer (n = 35, 492) by prior cancer status

Characteristics	No previous cancer, n = 31491 (88.73%)		With prior cancer, n = 4001 (11.27%)		P value
Age (yr)					< 0.001
< 65	13160	(41.79%)	714	(17.85%)
≥ 65	18331	(58.21%)	3287	(82.15%)
Sex					< 0.001
Male	19479	(61.86%)	2777	(69.41%)
Female	12012	(38.14%)	1224	(30.59%)
Race					< 0.001
White	22087	(70.14%)	2926	(73.13%)
Black	4090	(12.99%)	555	(13.87%)
AI/AN	285	(0.91%)	16	(0.4%)
AP	4898	(15.55%)	504	(12.6%)
Unknown	131	(0.42%)	0	(0%)
Marital status					< 0.001
Married	17571	(55.80%)	2366	(59.14%)
Unmarried	12473	(39.61%)	1416	(35.39%)
Unknown	1447	(4.59%)	219	(5.47%)
Site
Cardia and Fundus	10537	(33.46%)	1486	(37.14%)
Body of stomach	6340	(20.13%)	844	(21.09%)
Antrum and Pylorus	7370	(23.40%)	862	(21.54%)
Stomach, NOS	7244	(23.00%)	809	(20.22%)
Lymph nodes examined					< 0.001
No examined	16884	(53.62%)	2287	(57.16%)
1-15	7020	(22.29%)	909	(22.72%)
≥ 16	6338	(20.13%)	686	(17.15%)
Unknown	1249	(3.97%)	119	(2.97%)
Positive lymph nodes					< 0.001
0	4914	(36.79%)	693	(43.45%)
1-2	2599	(19.46%)	327	(20.50%)
3-6	2399	(17.96%)	276	(17.30%)
7-15	2355	(17.63%)	207	(12.98%)
≥ 16	1066	(7.98%)	89	(5.58%)
Unknown	25	(0.19%)	3	(0.19%)
SEER stage					< 0.001
Localized	7209	(22.89%)	1190	(29.74%)
Regional	8978	(28.51%)	1051	(26.27%)
Distant	12615	(40.06%)	1242	(31.04%)
Unstaged	2689	(8.54%)	518	(12.95%)
Grade					< 0.001
G1	1087	(3.45%)	181	(4.52%)
G2	7012	(22.27%)	1027	(25.67%)
G3	18112	(57.51%)	2108	(52.69%)
G4	567	(1.80%)	68	(1.70%)
Unknown	4713	(14.97%)	617	(15.42%)
Surgery					0.088
No	16692	(53.01%)	2194	(54.84%)
Yes	14630	(46.46%)	1785	(44.61%)
Unknown	169	(0.54%)	22	(0.55%)
Radiation					< 0.001
None	23413	(74.35 %)	3098	(77.43%)
Radiation	7789	(24.73%)	866	(21.64%)
Unknown	289	(0.92%)	37	(0.92%)
Chemotherapy					< 0.001
No/Known	17189	(54.58%)	2569	(64.21%)
Chemotherapy	14302	(45.42%)	1432	(35.79%)

AI/AN: American Indian/Alaska Native; AP: Asian or Pacific Islander; G1: Well-differentiated; G2: Moderately differentiated; G3: Poorly differentiated; G4: Undifferentiated.