P0168 - Impact of Race on Increasing Incidence of Rectal Neuroendocrine Tumors in Younger Adults: A Population-Based Time-Trend Analysis Using the United States Cancer Statistics Database, 2001-2019

Sunday, October 22, 2023

3:30 PM – 7:00 PM PT

Location: Exhibit Hall

Has Audio

Presenting Author(s)

Yazan Abboud, MD

Rutgers New Jersey Medical School
Newark, NJ

Yazan Abboud, MD¹, Navya Pendyala, BA¹, Anmol Mittal, MD¹, Alexander Le, MD¹, Saqr Alsakarneh, MD², Kaveh Hajifathalian, MD, MPH¹
¹Rutgers New Jersey Medical School, Newark, NJ; ²University of Missouri-Kansas City, Kansas City, MO

Introduction: Previous data showed increasing incidence of rectal neuroendocrine tumors (RNET) in the US in younger adults. However, there are limited data on recent age and sex-specific incidence rates in different race groups. The aim of this study was to conduct a time-trend analysis of RNET incidence rates using a nationwide US database, the USCS database.

Methods: RNET age-adjusted incidence rates between 2001-2019 were calculated using SEER*Stat software from the USCS database, covering ~98% of US population. Tumor location was specified as Rectum and Rectosigmoid Junction and histopathological type was identified using ICD-O-3 codes. The rates were categorized by sex and age into older adults( >55 years), and younger adults(< 55 years), and by race into Non-Hispanic White(NHW), Non-Hispanic Black(NHB), Hispanic(H), and Non-Hispanic Asian/Pacific Islander(NHAPI). Time-trends, reported as annual percentage change(APC) and average APC(AAPC), were calculated using Joinpoint Regression and Monte Carlo permutation analysis. Pairwise comparison was conducted between age-specific trends using the tests of parallelism and coincidence and the absolute AAPC difference was evaluated(2-sided P-value cut-off at 0.05).

Results: There were 53,188 patients diagnosed with RNET in the US between 2001-2019. In NHW(28,322 patients), RNET incidence rates were significantly increasing in younger adults and decreasing in older adults(AAPC= 3.75 vs -0.76; AAPC difference=4.52, P< 0.001). In NHB(15,145 patients), the incidence rates were also increasing in younger adults but not in older adults(AAPC=3.72 vs -0.29; AAPC-difference=4, P=0.01). Similar results were seen in H(6,504 patients) with increasing rates in younger but not older adults(AAPC=3.41 vs 0.47; AAPC-difference=2.94, P< 0.001). Similar results were also seen in NHAPI(4,321 cases), AAPC-difference=3.49, P=0.003.

Discussion: Our nationwide study, covering ~98% of US population, suggests that RENT incidence trends were increasing in younger adults while decreasing or stable in older adults over the last two decades. The age-specific difference was seen in all race groups (NHW, NHB, H, and NHAPI). While this increase can be due to improvement in detection modalities, a true increase in incidence can’t be ruled out, especially with growing data showing increasing incidence of colorectal cancer and other GI malignancies in younger adults. Future studies are warranted to assess risk factors and outcomes of RENT in younger adults.

Figure: Figure: Age-specific Trends and Incidence Rates Per 100,000 Population for Rectal Neuroendocrine Tumors (RNET) Among Different Race Groups.
A: The average annual percentage change (AAPC) is increasing in younger NHW while decreasing in older NHW with a significant difference (3.75 vs -0.76; P<0.001), and non-parallel (P<0.001) non-identical (P<0.001) trends.
B: The average annual percentage change (AAPC) is increasing in younger NHB while stable in older NHB with a significant difference (3.72 vs -0.29; P=0.01), and non-parallel (P<0.001) non-identical (P<0.001) trends.
C: The average annual percentage change (AAPC) is increasing in younger H while stable in older H with a significant difference (3.41 vs 0.47; P<0.001), and non-parallel (P<0.001) non-identical (P<0.001) trends.
D: The average annual percentage change (AAPC) is increasing in younger NHAPI while stable in older NHAPI with a significant difference (3.75 vs 0.26; P=0.003), and non-parallel (P=0.03) non-identical (P<0.001) trends.

Age group, y	Cancer Cases (N= 53,188)^a	Trends^b			Age-specific AAPC difference^c (95% CI)	Pairwise comparison P-values
		Time period	APC (95% CI)	AAPC (95% CI)		Age-specific AAPC difference	Coincidence^d	Parallelism^e
Non-Hispanic White
Younger Adults	13,131 (24.7%)	2001-2008	7.48 (6.10 to 8.87)	3.75 (2.11 to 5.42)	4.52 (2.78 to 6.25)	< 0.001	< 0.001	< 0.001
		2008-2011	-2.30 (-10.34 to 6.45)
		2011-2015	4.72 (0.39 to 9.23)
		2015-2019	1.11 (-1.50 to 3.79)
Older Adults	15,191 (28.6%)	2001-2019	-0.76 (-1.33 to -0.19)	-0.76 (-1.33 to -0.19)
Z. Non-Hispanic Black
Younger Adults	7,171 (13.7%)	2001-2009	8.43 (6.39 to 10.49)	3.72 (1.03 to 6.48)	4.00 (0.91 to 7.10)	0.01	< 0.001	< 0.001
		2009-2012	-2.97 (-15.54 to 11.48)
		2012-2017	5.63 (1.39 to 10.04)
		2017-2019	-8.31 (-19.80 to 4.84)
Older Adults	7,874 (14.8%)	2001-2016	1.06 (0.17 to 1.95)	-0.29 (-1.74 to 1.19)
		2016-2019	-6.75 (-14.43 to 1.61)
Hispanic
Younger Adults	3,479 (6.5%)	2001-2019	3.41 (2.56 to 4.27)	3.41 (2.56 to 4.27)	2.94 (1.70 to 4.19)	< 0.001	< 0.001	< 0.001
Older Adults	3,025 (5.7%)	2001-2019	0.47 (-0.55 to 1.50)	0.47 (-0.55 to 1.50)
Non-Hispanic Asian/Pacific Islander
Younger Adults	2,155 (4.1%)	2001-2007	9.18 (3.62 to 15.05)	3.75 (1.92 to 5.62)	3.49 (1.22 to 5.76)	0.003	< 0.001	0.03
		2007-2019	1.14 (-0.19 to 2.49)
Older Adults	2,166 (4.1%)	2001-2019	0.26 (-1.14 to 1.68)	0.26 (-1.14 to 1.68)

Table: Table: Age-Specific Trends for Rectal Neuroendocrine Tumors (RNET) Incidence Rates Among Different Race Groups.
a Data are presented as count numbers followed by percentages of the count numbers from the total cases of RNET cancer in the database.
b Time-trends were computed using Joinpoint Regression Program (v4.9.0.1, NCI) with 3 maximum joinpoints allowed (4-line segments).
c A positive value indicates a greater AAPC in younger adults compared to older adults.
d Tests whether age-specific trends were identical. A significant P-value indicates that the trends were not identical (i.e., they had different incidence rates and coincidence was rejected).
e Tests whether age-specific trends were parallel. A significant P-value indicates that the trends were not parallel (i.e., parallelism was rejected).

Disclosures:

Yazan Abboud indicated no relevant financial relationships.

Navya Pendyala indicated no relevant financial relationships.

Anmol Mittal indicated no relevant financial relationships.

Alexander Le indicated no relevant financial relationships.

Saqr Alsakarneh indicated no relevant financial relationships.

Kaveh Hajifathalian indicated no relevant financial relationships.

Yazan Abboud, MD¹, Navya Pendyala, BA¹, Anmol Mittal, MD¹, Alexander Le, MD¹, Saqr Alsakarneh, MD², Kaveh Hajifathalian, MD, MPH¹. P0168 - Impact of Race on Increasing Incidence of Rectal Neuroendocrine Tumors in Younger Adults: A Population-Based Time-Trend Analysis Using the United States Cancer Statistics Database, 2001-2019, ACG 2023 Annual Scientific Meeting Abstracts. Vancouver, BC, Canada: American College of Gastroenterology.