Incidence Trends in Upper Gastrointestinal Cancer in Young Adults: A Nationwide Time-Trend Analysis Using 2001-2019 US Cancer Statistics Databases.

Introduction: Upper gastrointestinal (UGI) cancers, comprising malignancies of the esophagus, stomach, duodenum, pancreas, liver, biliary tract, and gallbladder, are the second leading cause of cancer-related mortality in the United States and are associated with significant comorbidities. Recent studies show a disproportionate rise in pancreatic and stomach cancer among young adults. This study aims to use a nationwide, population-based cohort to (i) evaluate the trend of all UGI cancer as an aggregate and (ii) examine the role of demographics, histology, and tumor stage in UGI cancer incidence among young adults.

Methods: Individuals diagnosed with UGI cancer in the United States from 2001 to 2019 were identified and obtained from the Surveillance, Epidemiology, and End Results-National Program of Cancer Registries database. The primary outcomes were incidence rates of UGI cancer (calculated per 100,000, age-adjusted to the year 2000 US population), stratified by sex and age (< 55 years for young adults and ≥ 55 years for older adults). Trends, annual percentage change, and average annual percentage change were calculated using the parametric method. Sensitivity analysis was performed according to primary site and histology; further analysis examining race and cancer stage was performed in the young adult subgroup.

Results: A total of 2,333,161 patients with UGI cancer were identified. Most cases were male, and 14.3% were < 55 years of age. Incidence of UGI cancer increased most in women younger than 55 years, driven primarily by pancreatic and stomach cancers, as well as neuroendocrine tumor and gastrointestinal stromal tumor histology. African American race and localized tumors and malignancy with distant spread are also contributing to the disparate increase among young women. UGI mortality rates have not changed significantly in young adults.

Discussion: The overall incidence rate of upper gastrointestinal cancer is increasing significantly in young women compared with men. Increased endoscopic procedures and disparate exposure to risk factors are likely contributing to these trends.