Histologic and Racial/Ethnic Patterns of Appendiceal Cancer among Young Patients

Area of Science:

• Oncology
• Epidemiology
• Cancer Research

Background:

• Appendiceal cancer incidence is increasing in individuals under 50 years old (early-onset appendiceal cancer).
• The etiologies and distinct clinicopathologic/demographic features of early-onset appendiceal cancer are not well understood.
• This study compares appendiceal cancer patterns across different age groups at disease onset.

Purpose of the Study:

• To investigate and compare the clinicopathologic and demographic features of appendiceal cancer based on age of onset.
• To identify potential differences in tumor types and patient characteristics between early-onset and late-onset appendiceal cancer.

Main Methods:

• Utilized data from the NIH/NCI's Surveillance, Epidemiology, and End Results (SEER) program (2007-2016).
• Included individuals aged 20+ years diagnosed with appendiceal cancer.
• Employed Cochran-Armitage trend tests and multinomial logistic regression to analyze age-related differences.

Main Results:

• A total of 8,851 appendiceal cancer patients were identified.
• Histologic subtype, tumor grade, stage, sex, and race/ethnicity significantly differed by age at diagnosis.
• Early-onset appendiceal cancer patients were more likely to be Hispanic or American Indian/Alaska Native and diagnosed with neuroendocrine tumors (goblet cell carcinoid, carcinoid).
• Early-onset neuroendocrine tumors were less likely to be high-grade.

Conclusions:

• Approximately one-third of appendiceal cancer patients in the U.S. are diagnosed before age 50.
• Appendiceal cancer in young patients is characterized by distinct histologic and demographic features.
• Understanding these early-onset determinants can guide the discovery of risk factors and biomarkers for improved prevention, detection, and treatment.