Incidence and Geographical Distribution of Adrenocortical Carcinoma: Retrospective Analysis of a State Cancer Registry

Abstract

Objective: Adrenocortical carcinoma (ACC) is a rare malignancy without established association with environmental risk factors. ACC incidence is stable based on large surgical databases while referral centers data reported increasing number of cases seen. We studied ACC incidence and distribution at a county level to find potential ACC "hot spots" that could be linked to environmental exposures.

Methods: A retrospective analysis of Texas Cancer Registry that included ACC patients diagnosed between 2000 and 2018. County-level heatmaps were created and compared with breast, prostate, and lung cancer.

Results: We identified 448 ACC cases during the study period. Cases were registered in 110 of the 254 counties (43.3%) in Texas, representing 92.74% of the total population. The median incidence was 23 new cases/y (range 14-33). The mean population-adjusted ACC incidence rate was 0.104 per 100 000 per year (standard deviation 0.005; 95% CI, 0.092-0.116). Seven counties (6.3%) accounted for 215 (48.0%) cases, with more than 10 cases each and median standardized incidence ratio (SIR) of 0.1 (range, 0.0-0.9). One hundred three counties (93.7%) accounted for the remaining 233 cases (52%), with fewer than 10 cases per county. The highest standardized incidence ratios were found in counties with a median population of fewer than 14 000 residents and with only one reported case.

Conclusion: Our analysis is the first report to create ACC heatmap and could not detect any geographic clustering of ACC in Texas. The incidence of ACC remained stable and consistent with data from other large databases.

Keywords: Texas; adrenocortical carcinoma; cancer incidence; heatmap; rare disease.