Abstract A108: Differences in incidence by sex and race/ethnicity of adrenocortical carcinomas and malignant pheochromocytomas and paragangliomas in California
Authors: Mulvey Claire K. , Paciorek Alan , Shih Brandon , McKinley Meg , Pearson Dawn , Cheng Iona , Zhang Li , Griffin Ann , Duh Quan-Yang , Roman Sanziana , Sosa Julie Ann , Suh Insoo , Liu Chienying , Van Loon Katherine , Bergsland Emily 
Published: September 2020

Background: Malignant pheochromocytomas (PHEO), paragangliomas (PGL), and adrenocortical carcinomas (ACC) are rare endocrine malignancies with limited data regarding risk factors. To further elucidate their epidemiology, we sought to characterize the burden of malignant PHEO, PGL, and ACC in California. Methods: Using the population-based California Cancer Registry, we identified all new diagnoses of malignant PHEO, PGL, and ACC in California from 1992-2016 (ICD-O-3 codes 8700/3, 8680/3, and 8393/3). We calculated age-adjusted incidence rates (AIR) standardized to the 2000 United States census. We compared AIRs by sex, race/ethnicity (non-Hispanic White, non-Hispanic Black, Hispanic, and Asian/Pacific Islander), and county of residence (categorized as urban versus suburban/rural) using SEER*Stat and generated IR ratios (IRR). Results: Between 1992-2016, there were 261 incident cases of malignant PHEO, 271 of malignant PGL, and 866 of ACC in California. Overall AIR per 100,000 person-years were 0.03 for PHEO, 0.03 for PGL, and 0.10 for ACC. Incidence differed by both sex and race/ethnicity. Men had a higher incidence of PGL than women (IRR 1.49, 95% confidence interval [CI] 1.13-1.98; p&lt;0.05) and tended towards higher incidence of PHEO (IRR 1.24, 95% CI 0.97-1.60; p=0.09), while men had a lower incidence of ACC than women (IRR 0.80, 95% CI 0.69-0.92; p&lt;0.05). Compared with non-Hispanic White Californians, non-Hispanic Black Californians had higher PHEO incidence (IRR 1.65, 95% CI 1.05-2.51; p&lt;0.05), whereas PGL incidence was lower for Hispanic (IRR 0.60, 95% CI 0.41-0.87; p&lt;0.05) and Asian/Pacific Islander Californians (IRR 0.60, 95% CI 0.35-0.97; p&lt;0.05). Compared with non-Hispanic White Californians, ACC incidence was lower in non-Hispanic Black (IRR 0.58, 95% CI 0.40-0.82; p&lt;0.05), Hispanic (IRR 0.65, 95% CI 0.54-0.78; p&lt;0.05), and Asian/Pacific Islander Californians (IRR 0.60, 95% CI 0.46-0.76; p&lt;0.05). There were no differences in IRRs according to county of residence for either PHEO, PGL, or ACC. Conclusions: Malignant PHEO, PGL, and ACC remain rare cancers in California, with disease-specific differences in IRR’s by sex and race/ethnicity but not by urban versus suburban/rural county of residence. We report novel findings of a higher incidence of malignant PHEO in non-Hispanic Black Californians and a lower incidence of malignant PGL in Hispanic and Asian/Pacific Islander Californians. We also confirm higher incidence of ACC in women and non-Hispanic White Californians. Additional research is needed to clarify whether these differences reflect disparities in access to care.

Citation Format: Claire K. Mulvey, Alan Paciorek, Brandon Shih, Meg McKinley, Dawn Pearson, Iona Cheng, Li Zhang, Ann Griffin, Quan-Yang Duh, Sanziana Roman, Julie Ann Sosa, Insoo Suh, Chienying Liu, Katherine Van Loon, Emily Bergsland. Differences in incidence by sex and race/ethnicity of adrenocortical carcinomas and malignant pheochromocytomas and paragangliomas 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 A108.