E0693 - Rural-Urban Disparities in Early Onset Gastric Cancer Among Hispanics and Non-Hispanics

Tuesday, October 25, 2022

3:00 PM – 5:00 PM ET

Location: Crown Ballroom

Presenting Author(s)

Manasa Narasimman, MD

UTSW Medical Center
Dallas, TX

Manasa Narasimman, MD, Bhumika Maddineni, MPH, Sandi Pruitt, PhD, Caitlin Murphy, MPH, PhD, Amit Singal, MD, MS, Anna Tavakkoli, MD, MSc
UTSW Medical Center, Dallas, TX

Introduction: The incidence of non-cardia gastric cancer is increasing in adults younger than 50 years old. Early-onset non-cardia gastric cancer (EOGC) is characterized by racial and ethnic disparities, occurring more often in Hispanic than non-Hispanic persons. Rural-urban disparities in incidence have been described for several other cancers such as colorectal cancer; however, it is unknown whether rural-urban disparities exist in EOGC and if this intersects with racial and ethnic disparities given the majority of Hispanic persons reside in urban areas.

Methods: We utilized the SEER Census Tract-level Socioeconomic Status and Rurality Database from 2006-2018 to calculate incidence rates (IR) and incidence rate ratios (IRR) of EOGC among Hispanic and non-Hispanic persons by census tract rural-urban location, age, year, and stage of disease. We estimated age-adjusted (to the 2000 US standard population) IRs per 100,000 persons using SEER*Stat version 8.4.0. We used Tiwari method to estimate IRRs with 95% CIs, comparing rates in 2006 and 2018 among Hispanic and non-Hispanic persons in rural and urban settings and Joinpoint software (v4.9.1.0) to evaluate annual percent change (APC).

Results: Incidence rates of EOGC were significantly higher among Hispanic persons than non-Hispanic persons in both rural settings (1.44 vs. 0.68 per 100,000 persons; IRR 2.12, 95% CI 1.64-2.73) and urban settings (1.75 vs. 0.86 per 100,000 persons; IRR 2.04, 95% CI 1.91-2.16). Hispanic persons had higher incidences of EOGC in both rural and urban settings in every age group and stage (Table 1). From 2006 to 2018 the APC was 1.40% for Hispanic persons living in rural census tracts compared to -10.38% from 2006 to 2011 (p< 0.05), 17.45% from 2011-2014 (p >0.1), and not calculable from 2014-2018 among non-Hispanic persons (Figure 1). In urban census tracts, the APC was 0.75% for Hispanic persons (p >0.1) compared to -0.27% from 2006 to 2013, -2.92% from 2013 to 2016, and not calculable from 2016-2019 for non-Hispanic persons (p >0.1) (Figure 1). The largest absolute difference was among urban 30-39 year-old Hispanic persons (APC 3.49%).

Discussion: There were marked disparities in incidence rates of EOGC among Hispanics and non-Hispanics, but these disparities did not differ by rural-urban locations. Further studies are needed to determine factors contributing to disparities among Hispanic and non-Hispanic persons with EOGC.

Figure: Rural-Urban Annual Percent Change in Early Onset Gastric Cancer among Hispanics and Non-Hispanics

		Rural			Urban
	IR Hispanic (95% CI)	IR Non-Hispanic (95% CI)	IRR (95% CI)	IR Hispanic (95% CI)	IR Non-Hispanic (95% CI)	IRR (95% CI)
Age
20-29	0.11 (0.02-0.32)	0.05 (0.02-0.11)	2.23 (0.36-10.47)	0.31 (0.26-0.37)	0.14 (0.12-0.16)	2.23 (1.74-2.84)*
30-39	1.17 (0.77-1.7)	0.51 (0.39-0.66)	2.29 (1.39-3.67)*	1.36 (1.25-1.49)	0.62 (0.57-0.67)	2.19 (1.94-2.46)*
40-49	2.84 (2.14-3.69)	1.38 (1.18-1.59)	2.06 (1.50-2.80)*	3.35 (3.15-3.55)	1.7 (1.63-1.78)	1.97 (1.82-2.12)*
Stage
In situ/localized	0	0	-	0	0	-
Regional	0.77 (0.56-1.03)	0.41 (0.35-0.49)	1.86 (1.30-2.60)*	0.84 (0.79-0.90)	0.49 (0.46-0.51)	1.73 (1.59-1.89)*
Distant	0.57 (0.39-0.79)	0.19 (0.15-0.24)	3.02 (1.93-4.61)*	0.67 (0.62-0.72)	0.26 (0.24-0.28)	2.55 (2.30-2.83)*

Table: Age-Adjusted Incidence Rates (IR) and Incidence Rate Ratios (IRR) of Early Onset Gastric Cancer Among Hispanics and Non-Hispanics in Rural and Urban Census Tracts by Age and Stage of Disease

*p<0.05

Disclosures:

Manasa Narasimman indicated no relevant financial relationships.

Bhumika Maddineni indicated no relevant financial relationships.

Sandi Pruitt indicated no relevant financial relationships.

Caitlin Murphy: Freenome – Consultant.

Amit Singal: AstraZeneca – Consultant. Bayer – Consultant. BMS – Consultant. Eisai – Consultant. Exact Sciences – Consultant. Exelixis – Consultant. FujiFilm Medical Sciences – Consultant. Genentech – Consultant. Glycotest – Consultant. GRAIL – Consultant. Roche – Consultant.

Anna Tavakkoli indicated no relevant financial relationships.

Manasa Narasimman, MD, Bhumika Maddineni, MPH, Sandi Pruitt, PhD, Caitlin Murphy, MPH, PhD, Amit Singal, MD, MS, Anna Tavakkoli, MD, MSc. E0693 - Rural-Urban Disparities in Early Onset Gastric Cancer Among Hispanics and Non-Hispanics, ACG 2022 Annual Scientific Meeting Abstracts. Charlotte, NC: American College of Gastroenterology.