D0688 - Obesity as a Risk Factor for Gastric Cancer in a Diverse Population: Investigating the Multiethnic Cohort

Tuesday, October 25, 2022

10:00 AM – 12:00 PM ET

Location: Crown Ballroom

Presenting Author(s)

NM

Niharika Mallepally, MD, MPH

Keck School of Medicine, University of Southern California
Los Angeles, CA

Niharika Mallepally, MD, MPH, Tiffany Lim, MS, Brian Huang, PhD, Wendy Setiawan, PhD
Keck School of Medicine, University of Southern California, Los Angeles, CA

Introduction: Gastric cancer is the fifth most common and third deadliest cancer worldwide. The rate of cardia gastric cancer is on the rise, possibly due to obesity. Literature exploring the association between obesity and gastric cancer has focused primarily on white populations. Therefore, an assessment of obesity and gastric cancer risk in ethnically diverse populations is needed.

Methods: The Multiethnic Cohort (MEC) is a population-based prospective study that has followed ~215,000 participants since the early 1990s. Gastric cancer (GC) cases were identified from linkages to tumor registries in California and Hawaii. Self-reported body mass index (BMI), weight, smoking, alcohol consumption, and family history of GC were obtained from the baseline questionnaire. Hazard ratios (HR) and 95% confidence intervals (CI) were calculated via Cox proportional hazards models to estimate the association between anthropometric variables and GC incidence by tumor site.

Results: During an average 19.4 years of follow-up, 1458 GC cases (192 cardia, 779 non-cardia) were identified among 166,505 participants. Amongst cases, mean age at cohort entry was 63.8 years and at time of diagnosis was 75.6 years. Most gastric cancer patients were male (59.7%), Japanese (47.6%) or Latino (22.1%), former smokers (44.5%), without family GC history (89%), and with no daily alcohol intake (52.1%). In this population, we did not find statistically significant trends in overall GC incidence based on weight or BMI. Significant associations were observed for cardia cancer: increased BMI at age 21 (HR 1.41, 95% CI 1.14-1.75), BMI at baseline (HR 1.29, 95% CI 1.1-1.52), weight at age 21 (HR 1.11, 95% CI 1.04-1.17), and weight at baseline (HR 1.08, 95% CI 1.03-1.13) were each associated with an higher risk of cardia gastric cancer. Higher weight at age 21 (HR 0.95, 95% CI 0.91-0.99), weight at baseline (HR 0.96, 95% CI 0.94-0.99), BMI rate of change (HR 0.44, 95% CI 0.22-0.92), and a weight rate of change (HR 0.86, 95% 0.77-0.97) were each associated with decreased NCGC risk. Results were similar in a sensitivity analysis that excluded cases diagnosed within 3 years of cohort entry.

Discussion: In this ethnically diverse cohort study, we showed an association between increasing BMI or weight and risk of cardia gastric cancer. Given the increasing incidence of cardia gastric cancer and obesity, understanding the relationship between the two is imperative and could be used to guide future risk stratification and screening guidelines.

Figure: Table 4 – Association between BMI and weight change and cardia/non-cardia

	Cardia		Non-cardia
	Cases	HR (95% CI)	Cases	HR (95% CI)
BMI at age 21 per 5kg/m2	192	1.41 (1.14, 1.75)	779	0.92 (0.81, 1.05)
BMI at baseline per 5kg/m2	192	1.29 (1.10, 1.52)	779	0.93 (0.85, 1.02)
BMI change per 5kg/m2	192	1.10 (0.91, 1.32)	779	0.96 (0.88, 1.06)
BMI change
> -5 kg/m2	0	0	7	1.65 (0.78, 3.49)
-5 to 5 kg/m2	119	1.0	491	1.0
5 to 10 kg/m2	58	1.07 (0.78, 1.48)	226	1.00 (0.85, 1.17)
10 to 15 kg/m2	10	1.01 (0.52, 1.95)	40	0.86 (0.62, 1.20)
>15 kg/m2	5	2.12 (0.85, 5.32)	15	1.15 (0.68, 1.94)
BMI rate of change (kg/m2 per year)	192	1.65 (0.42, 6.52)	779	0.44 (0.22, 0.92)
Weight at age 21 per 10 lbs	192	1.11 (1.04, 1.17)	779	0.95 (0.91, 0.99)
Weight at baseline per 10 lbs	192	1.08 (1.03, 1.13)	779	0.96 (0.94, 0.99)
Weight change per 10 lbs	192	1.03 (0.97, 1.09)	779	0.98 (0.95, 1.01)
Weight change
> -10 lbs	5	0.52 (0.21, 1.31)	30	1.04 (0.70, 1.54)
-10 to 10 lbs	47	1.0	151	1.0
10 to 30 lbs	58	0.57 (0.38, 0.83)	302	0.95 (0.78, 1.16)
30 to 50 lbs	52	0.78 (0.52, 1.17)	184	0.94 (0.75, 1.17)
>50 lbs	30	0.74 (0.46, 1.19)	112	0.91 (0.70, 1.18)
Weight rate of change (10lbs per year)	192	1.08 (0.87, 1.34)	779	0.86 (0.77, 0.97)

Table: Table 4 – Association between BMI and weight change and cardia/non-cardia

Disclosures:

Niharika Mallepally indicated no relevant financial relationships.

Tiffany Lim indicated no relevant financial relationships.

Brian Huang indicated no relevant financial relationships.

Wendy Setiawan indicated no relevant financial relationships.

Niharika Mallepally, MD, MPH, Tiffany Lim, MS, Brian Huang, PhD, Wendy Setiawan, PhD. D0688 - Obesity as a Risk Factor for Gastric Cancer in a Diverse Population: Investigating the Multiethnic Cohort, ACG 2022 Annual Scientific Meeting Abstracts. Charlotte, NC: American College of Gastroenterology.