Gastric cancer is a heterogeneous disease with a global health disparity. There remains a debate as to why some ethnicities have a better survival than other ethnicities. This study examines differences in gastric cancer in the US versus Korea. there are some significant differences that may point to their differences in survival and patient outcome.

1. Gastric Cancer Survival after
R0 Resection in the
United States and Korea
Strong V et al. Ann Surg 2010

2. Methods
2 Gastric Ca Databases 1995-2005
Gastric Carcinoma R0 resection
United States
n=1,027
Korea
n=2,053
- 316 patients *
n=711
- 407 patients *
n=1,646
* with pre-operative chemo, other malignancy, final status R1/M1
Gastric Ca - US and Korea

3. Patient Demographics
Korea US P value
Total Cases 1,646 711 --
Gender Male 1,096 (67%) 425 (60%) 0.002
Median age (range) 59 (18-91) 69 (22-96) <0.0001
BMI kg/m2 (range) 23 (14-36) 25 (14-48) <0.0001
Family History 87 (5%) 92 (13%) <0.0001
Race
Caucasian
Asian
Hispanic
AA
Other
--
1,646 (100%)
--
--
--
538 (76%)
74 (10%)
53 (7%)
45 (6%)
1 (0.1%)
<0.0001
Gastric Ca - US and Korea

4. Pathological Characteristics
Korea
n=1,646
US
n=711
P value
Lymphadenectomy
D1
D2/D3
Unknown
182 (11%)
1,464 (89%)
-
109 (15%)
597 (84%)
5 (1%)
0.003
Differentiation
Differentiated
Undifferentiated
Unknown
770 (47%)
857 (52%)
19 (1%)
361 (51%)
342 (48%)
8 (1%)
0.07
Lauren Classification
Diffuse
Intestinal
Mixed
Unknown
623 (38%)
729 (44%)
257 (16%)
37 (2%)
203 (29%)
419 (59%)
79 (11%)
10 (1%)
<0.0001
Gastric Ca - US and Korea

5. Pathological Characteristics
Korea n=1,646 US n=711 P value
Location of Tumor
GE Junction
Upper
Middle
Lower
Whole
Unknown
7 (0.4%)
142 (9%)
592 (36%)
886 (54%)
7 (0.4%)
12 (1%)
131 (18%)
146 (21%)
189 (27%)
232 (33%)
13 (2%)
--
<0.0001
Med tumor size cm 3.5 (0.1 – 20.0) 3.5 (0.0 – 21.0) 0.58
Gastric Ca - US and Korea

6. Pathological Characteristics
Korea n=1,646 US n=711 P value
Stage
Ia
Ib
II
IIIa
IIIb
IV
Unknown
698 (42%)
337 (20%)
266 (16%)
169 (10%)
84 (5%)
196 (28%)
147 (21%)
141 (20%)
114 (16%)
54 (8%)
<0.0001
Gastric Ca - US and Korea

7. Operative Characteristics
and Mortality
Median (range) Korea n=1,646 United States
n= 711
P value
Procedure
Total Gastrectomy
Subtotal Gastrectomy
Prox Gastrectomy
Prox + Esophag
Total + Esophag
387 (24%)
1,254 (76%)
-
-
5 (0.3%)
147 (21%)
340 (48%)
51 (7%)
165 (23%)
8 (1%)
<0.0001
30-day Post Op
Mortality
4 (0.2%) 15 (2%) <0.0001
Gastric Ca - US and Korea

8. Overall and Disease-Specific
Survival
Korea
Pts 5-yr
US
Pts 5-yr
P value
Median F/U
yrs
6yrs (1-13) 6yrs (0.04-13) NS
Overall Surv 1,614 81% 711 58% <0.0001
Dis Spec Surv 1,498 82% 710 74% <0.0001
Gastric Ca - US and Korea

9. Curative Resections in the
United States compared to Korea
• After adjusting for all known confounding risk
factors, DSS for Korean GC patients remained
significantly better than that of U.S. patients by
20-30%.
– HR=1.3, 95% CI; 1.0-1.7, p=0.05
• This study cannot exclude inherent biologic
difference between gastric cancer in the US and
Korea that accounts for superior survival in
Korean patients.
Gastric Ca - US and Korea

10. Gastric Cancer Registry
• Model to study the biologic and
racial/ethnic diversity of disease

11. How do other known risk factors for gastric
cancer interact with the risk attributable due
to H. pylori ??
Salt
EtOH Tobacco
ASA
H.
Pylori
Family
Hx
SNPs Other Risk
Factors
Risk of Gastric Cancer

12. Proposal: to develop a risk prediction model for
H. pylori associated gastric cancer.
Tobacco
ASA
Family
Hx
Risk
Algorithm
Risk of H. pylori associated Non-cardia Gastric Cancer
SNPs Other Risk
Factors

13. Gastric Cancer and H. pylori:
Regional Differences
Crew and Neuget. World J Gastroenterol. 2006;12:354.
Gastric cancer
incidence in males
H pylori infection
prevalence in adults
Age-standardized rate
per 100,000 population
<5.9
<14.6
<23.6
<70.0
<9.6
>75%
65%-74%
55%-64%
<55%

14. Gastric Cancer
• Global Problem:
– 1st leading cause of GI-Cancer related
mortality world wide
– 5-year survival 14%
– Significant racial, ethnic, and
socioeconomic diversity
• Highest incidence in Japan, China, Eastern
Europe, and Central America
• 2/3 incidence in developing countries
Jemal et al. Cancer, 2005

15. Take Home Points:
Heterogenous Disease
• Three distinct disease subtypes
• GEJ/ Proximal
• Diffuse
• Intestinal
• Risk Factors
– H. pylori, family history, tobacco
– Polymorphisms may modify risk
– Fruits/ vegetables reduce risk

16. Take Home Points:
Heterogenous Disease
• Different biology for different Racial
Groups?
– Asians – better survival
– African Americans – worse survival