IDDF2023-ABS-0012 Gastrointestinal cancers are the leading cause of young onset cancer in the United States

Background

Emerging data suggest that the incidence of young-onset cancers, defined as cancer diagnosed in adults < 50 years, is increasing, but has not been systematically assessed. We aimed to evaluate temporal changes in the incidence of young-onset cancers in a large, nationwide cohort study.

Methods

We analyzed data from the National Cancer Institute’s Surveillance, Epidemiology, and End Results 17 registry from 2000 to 2019. Age-standardised incidence rates (ASIR) per 100,000 from 2010 to 2019 were extracted for young-onset cancers based on ICD-O-3 definitions, with rates age-adjusted to the United States standard population. The annual percentage change (APC) of the ASIRs were estimated via the SEER*Stat program.

Results

Between 2010 and 2019, a total of 562,145 cases of early-onset cancer (62.5% female) were recorded (IDDF2023-ABS-0012 Table 1). A total of 425,718 cases (75.7%) were White, 62,780 (11.2%) were Black, 55,976 (10.0%) were Asian or Pacific Islander individuals, 5120 (0.9%) were American Indian/Alaska Native and 12,551 (2.2%) were of unknown race. From 2010 to 2019, the annual percentage change of early-onset cancer was +0.276%, 95% CI 0.085 to 0.467%, p = 0.01(IDDF2023-ABS-0012 Table 2). There was lower APC in males vs females, -0.366 vs +0.667, p < 0.001. The APC in Whites, Blacks, Asians or Pacific Islanders, American Indian/Alaska Natives, and unknown races were +0.173, -0.637, +0.990, +1.170 and undefined, respectively. Gastrointestinal cancers were the fastest-growing cause of young-onset cancer (APC 2.161%, 95% CI: 1.660 - 2.665%), followed by urinary tract cancers (APC 1.336%, 95% CI: 0.607 – 2.070%), and breast cancers (APC 0.906%, 95% CI: 0.554 - 1.259%). Among gastrointestinal cancers, miscellaneous digestive organ cancers had the highest APC from 2010 to 2019 (APC 12.19%, 95% CI 9.99-14.43%), followed by cancers of the small intestine (APC 2.107%), stomach (APC 1.595%), and transverse colon (APC 1.689%).

Conclusions

The incidence of young-onset cancers is increasing in the United States. In particular, the incidence of the young-onset appendix, intrahepatic bile duct, and miscellaneous digestive organ cancers are rapidly rising. These data have important implications for surveillance strategies.