Geographical Variation in Adrenocortical Carcinoma Incidence Across Colorado

Adrenocortical carcinoma (ACC) is an aggressive endocrine malignancy with an annual incidence of approximately 1 case per million, with the underlying etiology poorly understood. We retrospectively investigated the geographic distribution of 62 ACC cases diagnosed between 2010 and 2023 and of 115 pheochromocytoma/paraganglioma (PPGL) diagnosed between 2016 and 2023 at the University of Colorado Hospital, as well as 115 ACC cases diagnosed between 2012 and 2020 from the Colorado Central Cancer Registry (CCCR). Data on patient age, sex, zip code of residence, and tumor characteristics were collected and, for ACC cases, compared with CCCR data. Our University of Colorado cohort showed an average ACC annual incidence of 0.81 cases per million, with 61.2% of cases occurring in women. The CCCR cohort showed an average ACC annual incidence of 1.1 cases per million, with 48.7% of cases in women. For PPGL, the average annual incidence was 2.26 cases per million, with 60% of cases occurring in females. Our ACC cohort had an average annual incidence of 1.36 cases per million in Western Colorado and 0.68 cases per million in Eastern Colorado. Similarly, the state registry showed 1.49 cases per million in Western Colorado and 1 case per million in Eastern Colorado. In contrast, PPGL data showed 1.35 cases per million in Western Colorado and 2.36 cases per million in Eastern Colorado. These data suggest a higher incidence of ACC in Western Colorado, highlighting the need for investigation into environmental factors as potential pathogenic factors in ACC.