Abstract D111: Incidence and survival patterns of gastroenteropancreatic neuroendocrine neoplasms in California

Background. Neuroendocrine neoplasms (NEN) are a heterogeneous group of rare tumors. There is a paucity of epidemiologic data regarding risk factors. We aimed to characterize the burden of NEN in California with its diverse racial/ethnic populations. Methods Using California Cancer Registry, we identified all newly diagnosed NEN from gastroenteropancreatic (GEP) sites 1992-2015. Annual age-adjusted incidence rates (AIR) per 100,000 person-years were compared, and average annual percent change (APC) in rates were compared according to sex, race-ethnicity (non-Hispanic (NH) white, NH black, Asian/Pacific Islander, American Indian, Hispanic), primary tumor site (stomach, small intestine, colon or rectum, appendix, pancreas), stage, and type of county of residence (urban, suburban, rural) using incidence rate ratios (IRR). Overall survival from diagnosis to death by any cause was estimated by Kaplan-Meier method and compared using log-rank tests. Results There were 23,983 GEP NEN incident cases and 9,910 deaths 1992-2015. All AIRs increased over the 24 years, with the greatest increase in Hispanics with pancreatic NEN (APC 8.9). Rates for the period 2011-2015 varied according to primary tumor site: colorectal (AIR 1.41); small intestinal (AIR 0.97); pancreatic (AIR 0.92); stomach (AIR 0.44); and appendiceal (AIR 0.36). Comparing rates by populations the greatest disparities were for NH blacks vs. Asians with small intestinal NEN (IRR 7.01 95% confidence interval (CI) [5.37-9.21]) or appendiceal NEN (IRR 3.74 95% CI [2.34-6.08]), for NH whites vs. Asians with small intestinal NEN (IRR 4.34 95% CI [3.44-5.53]) or appendiceal NEN (IRR 5.10 95% CI [3.54-7.59]), for NH blacks vs. NH whites with colorectal NEN (IRR 2.59 95% CI [2.27-2.94]), and for NH whites vs. Hispanics with appendiceal NEN (IRR 2.54 95% CI [2.08-3.12]). Statistically significantly longer survival estimates were observed in women (median 13.1 years) vs. men (11.6 years), and in Asians/Pacific Islanders (20.7 years) and Hispanics (16.7 years) vs. NH blacks (12.3 years) and NH whites (9.6 years). No significant survival differences were detected across county types. Survival estimates were significantly different across primary tumor sites: colorectal (median 19.9 years); appendiceal (16.0 years); small intestinal (10.1 years); stomach (9.7 years); and pancreatic (4.4 years). Conclusions Incidence rates of GEP NEN in California steadily increase from 1992 through 2015 for all populations. Recent AIRs for particular race-ethnicities and primary tumor sites are more than double others, exposing large disparities. Survival estimates differ significantly by primary tumor site, sex, race-ethnicity, and stage, but not by county. These findings show some higher incidence rates and longer survival than in previously published estimates nationwide and add information about GEP NEN in Hispanic and Asian/Pacific Islander populations in California. Additional research is needed to clarify reasons for the disparities. Citation Format: Alan Paciorek, Brandon Shih, Meg McKinley, Iona Cheng, Li Zhang, Claire Mulvey, Ann Griffin, Eric Nakakura, Quan-Yang Duh, Insoo Suh, Katherine Van Loon, Emily Bergsland. Incidence and survival patterns of gastroenteropancreatic neuroendocrine neoplasms in California [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr D111.