1

Supplementary Table 1: Demographic and Clinical Characteristics of Patients with T4Gastric Adenocarcinoma Treated with MMT 1998-2006 vs. 2007-2011

Characteristic / 1998-2006
(%) / 2007-2011
(%) / Univariate
p-value1
Number of patients / 354
(11.2) / 298
(24.8) / --
Age quartiles (years)
<56
56-66
67-76
>76 / 122 (34.5)
122 (34.5)
88 (24.9)
22 (6.2) / 101 (33.9)
83 (27.9)
86 (28.9)
28 (9.4) / 0.15
Gender
Male
Female / 246 (69.5)
108 (30.5) / 198 (66.4)
100 (33.6) / 0.41
Race
White
Black
Asian
Other / 275 (77.7)
54 (15.3)
16 (4.5)
9 (2.5) / 217 (72.8)
47 (15.8)
23 (7.7)
11 (3.7) / 0.26
Hispanic ethnicity
No
Yes / 315 (89.0)
39 (11.0) / 253 (84.9)
45 (15.1) / 0.12
Charlson Comorbidity
Scorea
0
1
≥2 / 131 (77.1)
30 (17.6)
9 (5.3) / 225 (75.5)
56 (18.8)
17 (5.7) / 0.93
Insurance typeb
Private
Non-private / 173 (52.1)
159 (47.9) / 133 (46.0)
156 (54.0) / 0.13
Median Incomec
≥$46,000
<$46,000 / 107 (32.8)
219 (67.2) / 101 (36.3)
177 (63.7) / 0.37
Facility Location
Northeast
West
Midwest
South / 79 (22.3)
56 (15.8)
92 (26.0)
127 (35.9) / 63 (21.1)
60 (20.1)
65 (21.8)
110 (36.9) / 0.39
Urban/Rurald
Urban
Rural / 311 (96.0)
13 (4.0) / 276 (99.6)
1 (0.4) / 0.003
Facility Type
Academic
Non-academic / 152 (42.9)
202 (57.1) / 125 (41.9)
173 (58.1) / 0.80
Primary Tumor Location
Distal
Proximal
Lesser/Greater Curvature / 96 (27.1)
146 (41.2)
112 (31.6) / 86 (28.9)
95 (31.9)
117 (39.3) / 0.04
Clinical N classificatione
Node negative (N0)
Node positive (N1-3) / 101 (33.4)
201 (66.6) / 95 (35.4)
173 (64.6) / 0.62
Tumor Sizef*
<2 cm
2-5 cm
>5 cm / 13 (5.3)
94 (38.5)
137 (56.1) / 20 (8.4)
78 (32.9)
139 (58.6) / 0.24
Tumor Gradeg*
Well / moderately differentiated
Poorly / undifferentiated / 100 (29.9)
235 (70.1) / 93 (32.6)
192 (67.4) / 0.46
Resection Margin*
Margin negative (R0)
Margin positive / indeterminate / 219 (61.9)
135 (38.1) / 210 (70.5)
48 (29.5) / 0.02
Duration of Postoperative Stayh*
≤7 days
8-14 days
15-21 days
>21 days / 50 (32.9)
73 (48.0)
19 (12.5)
10 (6.6) / 101 (38.5)
111 (42.4)
33 (12.6)
17 (6.5) / 0.67
30-day readmissioni*
No readmission
Planned readmission
Unplanned readmission / 141 (87.6)
10 (6.2)
10 (6.2) / 264 (93.3)
14 (4.9)
5 (1.8) / 0.04

Abbreviations: MMT, multimodality therapy

aCharlson Comorbidity Score data was unavailable in 184 (1998-2006) patients; bInsurance type data was unavailable in 22 (1998-2006) patients and 9 (2007-2011) patients; cIncome data was unavailable in 28 (1998-2006) patients and 20 (2007-2011) patients; dUrban/rural data was unavailable in 30 (1998-2006) patients and 21 (2007-2011) patients; eClinical N classification data was unavailable in 52 (1998-2006) patients and 30 (2007-2011) patients; fTumor size data was unavailable in 110 (1998-2006) patients and 61 (2007-2011) patients; gTumor grade data was unavailable in 19 (1998-2006) patients and 13 (2007-2011) patients; hPost-operative LOS data was unavailable in 202 (1998-2006) patients and 36 (2007-2011) patients; iReadmission data was unavailable in 193 (1998-2006) patients and 71 (2007-2011) patients

*Variables were compared only between patients receiving surgical resection

lBold values indicate statistical significance

Supplementary Table 2: Predictors of risk-adjusted mortalityin the overallpatient cohort balanced with propensity scoring

Variable / Hazards Ratio / 95% CI / p-value1
Age quartiles (years)
<56
56-66
67-76
>76 / Ref
1.24
1.31
1.38 / 0.99-1.53
1.04-1.64
1.11-1.73 / 0.053
0.023
0.004
Hispanic ethnicity
No
Yes / Ref
0.64 / 0.50-0.82 / <0.001
Insurance type
Private
Non-private / Ref
1.35 / 1.13-1.61 / 0.001
Treatment Group
MMT
Surgery alone
C±RT alone
No treatment / Ref
2.26
2.65
6.59 / 1.65-3.10
2.09-3.35
5.10-8.52 / <0.001
<0.001
<0.001

Abbreviations: CI, confidence interval; MMT, multimodality therapy

1 Bold values indicate statistical significance