P0980 - Diverging Patterns of Cardia and Non-Cardia Gastric Adenocarcinoma Incidence by Race and Age in the United States From 2000-2018

Sung Eun Kim, MD, PhD¹, Robert J. Huang, MD², Joo Ha Hwang, MD, PhD^3
1Stanford University, Stanford, CA; ²Stanford University School of Medicine, Stanford, CA; ³Stanford University Medical Center, Palo Alto, CA

Introduction: Gastric adenocarcinoma is the fifth-leading cause of cancer incidence and fourth-leading cause of cancer mortality worldwide. In the United States (US), racial groups differ in their incidence of cardia (CGA) and non-cardia (NCGA) gastric adenocarcinomas. There have been few studies published observing secular trends in incidence of both CGA and NCGA stratified by race in the US.

Methods: Age-adjusted incidence rates and trends of CGA and NCGA in adults aged ≥ 25 years were calculated using data form 18 registries reporting to the Surveillance, Epidemiology, and End Results (SEER) Program from years 2000-2018. Race/ethnicity was classified as non-Hispanic White, non-Hispanic Black, American Indian/Alaskan Native, Asians/Pacific Islanders, and Hispanic. Analysis was also stratified by age (25-49 and ≥50). We used joinpoint regression to assess annual percent change (APC), average annual percent change (AAPC), and corresponding 95% confidence intervals (CIs).

Results: The incidence of NCGA decreased in all racial groups, regardless of age, across the study period. The incidence of CGA also decreased in all racial groups among individuals ≥50 (Table 1). However, among individuals 25-49, the incidence of CGA is increasing among non-Hispanic Whites (AAPC = 1.0, 95% CI; 0.3, 1.7), Asian/Pacific Islanders (AAPC = 2.5, 95% CI; -0.3, 5.4), and Hispanics (AAPC = 2.3, 95% CI; 0.9, 3.8) (Figure 1).

Discussion: NCGA incidence is decreasing in all racial and age groups. By contrast, CGA incidence in increasing in the young among certain racial/ethnic groups. Clinicians and policy makers must be cognizant of these recent and worrisome trends. Moreover, appropriate cancer prevention programs are needed to target these at-risk populations.


Figure: Figure 1. Age- and race-specific cardia gastric cancer incidence trends in the SEER data, 2000-2018
A. Non-Hispanic Whites aged 25-49
B. Non-Hispanic Asian/Pacific Islanders aged 25-49
C. Hispanics aged 25-49
D. Non-Hispanic Whites aged ≥50
E. Non-Hispanic Asian/Pacific Islanders aged ≥50
F. Hispanics aged ≥50

Race	Overall			Location	Overall			25-49 years			≥ 50 years
	AAPC (95% CI)	P-value			AAPC (95% CI)	P-value		AAPC (95% CI)	P-value		AAPC (95% CI)	P-value
Non-Hispanic White	-1.4 (-1.6, -1.2)	< 0.001		Cardia	0.2 (-0.2, 0.5)	0.363		1.0 (0.3, 1.7)	0.005		-0.3 (-1.1, 0.5)	0.395
				Non-cardia	-3.4 (-3.6, -3.1)	< 0.001		-†	-†		-3.7 (-3.9, -3.5)	< 0.001
Non-Hispanic Black	-2.8 (-3.3, -2.3)	< 0.001		Cardia	-1.2 (-1.9, -0.5)	0.002		0.0 (-2.3, 2.4)	0.969		-1.1 (-2.0, -0.2)	0.016
				Non-cardia	-3.2 (-3.7, -2.6)	< 0.001		-1.9 (-3.2, -0.5)	0.011		-3.3 (-3.9, -2.7)	< 0.001
Non-Hispanic American Indian/Alaska Native	-2.8 (-4.7, -0.9)	0.006		Cardia	-1.5 (-5.2, 2.3)	0.409		-†	-†		-2.2 (-6.3, 2.2)	0.302
				Non-cardia	-3.4 (-5.6, -1.3)	0.004		-0.8 (-4.8, 3.4)	0.698		-3.6 (-6.0, -1.1)	0.008
Non-Hispanic Asian or Pacific Islander	-3.6 (-4.1, -3.1)	< 0.001		Cardia	-1.0 (-2.2, 0.1)	0.082		2.5 (-0.3, 5.4)	0.076		-1.7 (-2.6, -0.7)	0.003
				Non-cardia	-4.1 (-4.6, -3.6)	< 0.001		-2.5(-3.8, -1.2)	0.001		-4.3 (-4.8, -3.7)	< 0.001
Hispanic (All Races)	-2.1 (-2.5, -1.8)	< 0.001		Cardia	-0.6 (-1.5, 0.2)	0.135		2.3 (0.9, 3.8)	0.004		-1.0 (-2.0, 0.0)	0.053
				Non-cardia	-2.6 (-2.9, -2.2)	< 0.001		-0.6 (-1.2, 0.1)	0.089		-2.8 (-3.2, -2.5)	< 0.001

Table: Table 1. Average annual percent change in cardia and non-cardia gastric cancer incidence rates by race and age: SEER 2000-2018
SEER, Surveillance, Epidemiology and End Results; AAPC, average annual percent change.
† Lack of data to analyze AAPC.



Disclosures:
Sung Eun Kim indicated no relevant financial relationships.
Robert J. Huang indicated no relevant financial relationships.
Joo Ha Hwang indicated no relevant financial relationships.


Sung Eun Kim, MD, PhD¹, Robert J. Huang, MD², Joo Ha Hwang, MD, PhD³. P0980 - Diverging Patterns of Cardia and Non-Cardia Gastric Adenocarcinoma Incidence by Race and Age in the United States From 2000-2018, ACG 2021 Annual Scientific Meeting Abstracts. Las Vegas, Nevada: American College of Gastroenterology.