Demographic and clinical factors associated with young-onset rectal cancer: Is the Latinx population at higher risk?

Abstract

11038 Background: The incidence of colorectal cancer is rising among younger adults, with some studies indicating a disproportionate increase in the Hispanic population. As one of the fastest-growing demographics in the United States, Hispanic individuals face unique barriers to cancer prevention and care. However, data specifically addressing disparities in rectal cancer within this group remain limited. The aim of our study is to elucidate demographic and clinical factors associated with young-onset rectal cancer (YO-RC) and evaluate if the Latinx population is at higher risk compared to other races. Methods: We evaluated patients ≥18 years of age with rectal cancer from the Surveillance, Epidemiology, and End Results (SEER) database, with a study period from 2018 to 2021. The study population included adult patients diagnosed with RC as first primary, histologically confirmed diagnoses, complete data on race, MSI status, stage, and known cause of death. A retrospective cohort study was done. Individuals were divided into two groups: young onset (diagnosed <50 years old) and average-onset (diagnosed at ≥50 years old). Univariate and multivariate logistic regression was done, adjusted logistic regression to race, sex, area of living, MSI status and stage. Results: A total of 13,768 individuals were analyzed, with 2,661 (19.33%) classified as YO-RC and 11,107 (80.67%) as AO-RC. In the YO-RC group, 60.28% were Non-Hispanic White (NHW), 21.20% Hispanic (H), 7.22% Non-Hispanic Black (NHB), 10.54% Non-Hispanic Asian or Pacific Islander (NHAPI), and 0.76% Non-Hispanic American Indian (NHAI). Most were male (58.51%) and diagnosed at advanced stages (43.03% stage III and 27.58% stage IV), with 93.24% having MSI-stable tumors. In the AO-RC group, NHW accounted for 68.46%, followed by H (12.52%), NHB (7.70%), NHAPI (10.46%), and NHAI (0.86%). Stage III (32.86%) and stage I (24.45%) were the most common stages, and 94.97% had MSI-stable tumors. H individuals were nearly twice as likely to have YO-RC compared to NHW (aOR 1.87, 95% CI 1.67–2.10, p<0.001). Females had a higher likelihood of YO-RC than males (aOR 1.14, 95% CI 1.04–1.24, p=0.002). MSI-high tumors were associated with YO-RC (aOR 1.57, 95% CI 1.27–1.94, p<0.001). Patients diagnosed at later stages were also more likely to have YO-RC (stage III aOR 1.99, 95% CI 1.76–2.25, p<0.001; stage IV aOR 1.98, 95% CI 1.73–2.26, p<0.001). Conclusions: Hispanic individuals are more likely to have YO-RC, which suggests the critical need for targeted outreach and earlier screening efforts within the young Latinx population. Female patients and those with MSI-high tumors were also more likely to have YO-RC suggesting possible biological and genetic influences, including Lynch syndrome. The strong correlation of advanced-stage diagnoses and YO-RC demonstrates the need to improve early detection efforts. Demographic and clinical factors associated with young-onset rectal cancer. Variable Unadjusted OR (95% CI) p value Adjusted OR (95% CI) p value Race Non-Hispanic White Ref. Hispanic 1.92 (1.71-2.14) <0.001 1.87 (1.67-2.10) <0.001 Non-Hispanic Black 1.07 (0.91-1.26) 0.386 1.03 (0.89-1.24) 0.658 Non-Hispanic Asian/PI 1.17 (1.02-1.35) 0.021 1.14 (0.99-1.32) 0.055 Non-Hispanic AI 0.49 (0.25-0.95) 0.037 0.48 (0.24-0.92) 0.029 Sex Male Ref. Female 1.12 (1.03-1.22) 0.007 1.14 (1.04-1.24) 0.002 Area of Living Non-Metropolitan Ref. Metropolitan 1.23 (1.08-1.41) 0.002 1.10 (0.95-1.26) 0.177 Socioeconomic Status <$40,000-79,999 Ref. *Not included due to collinearity $40,000-$79,999 0.89 (0.61-1.31) 0.576 $80,000-$100,000 0.95 (0.65-1.40) 0.818 >$100,000 0.93 (0.63-1.37) 0.738 MSI status MSI stable Ref. MSI low 1.15 (0.85-1.55) 0.357 1.08 (0.79-1.47) 0.604 MSI high 1.49 (1.21-1.83) <0.001 1.57 (1.27-1.94) <0.001 Stage I Ref. II 0.94 (0.85-1.10) 0.495 0.94 (0.81-1.10) 0.483 III 1.99 (1.76-2.25) <0.001 1.99 (1.76-2.25) <0.001 IV 1.97 (1.73-2.25) <0.001 1.98 (1.73-2.26) <0.001 Multivariate logistic regression, adjusted logistic regression is adjusted to race, sex, area of living, MSI status and stage. Income was not included due to a VIF >10, suggesting collinearity. ☨: p value <0.05, statistically significant.