Incidence trend of neuroendocrine tumors and disparities by sex and race/ethnicity in adults from the United States, 2000-2020.

Objective: The incidence of neuroendocrine tumors (NET) has been increasing globally for several decades. The objective of the study was to examine the most recent trend in the incidence of NET as well as disparities by sex and race/ethnicity in adults in the USA.

Methods: Patients with NET aged ≥20 years were identified from the SEER 22 Registries from 2000 to 2020. The age-adjusted incidence rate was calculated for overall NET and by primary site. The incidence trend was assessed by annual percent change. Disparities by sex and race/ethnicity were examined using the incidence rate ratio.

Results: Age-adjusted incidence rate of overall NET in adults was 9.39 per 100 000 in 2000-2020. The incidence rate increased from 2000 but reached a plateau with no significant change since 2015. The lung and bronchus, small intestine, and rectum were the most common primary sites. Sex and racial/ethnic disparities in NET incidence varied by primary sites. For example, there was a female excess in NET of the lung and bronchus, stomach, and appendix; and there was a male excess in the small intestine, pancreas, colon, rectum and other/unknown NET. Compared to non-Hispanic white, non-Hispanic black had higher incidences of stomach, small intestine, liver, pancreas, colon, rectum, and other/unknown NET; they had lower incidences of lung and bronchus, and appendix NET than non-Hispanic white.

Conclusion: Age-adjusted incidence rate of overall NET has reached a plateau since 2015. However, there were sex and racial/ethnic disparities in such incidence, which varied depending on the primary site of NET.