Introduction: Anal cancer (AC) is an uncommon malignancy and therefore its epidemiology is poorly understood. Recent data suggests an increase in incidence of AC in the United States (US), but the regional distribution of this disease is unknown. Our aim of this study was to determine the incidence rate variations of AC by geographic location, specifically by regions and states. Methods: Data was extracted from National Program of Cancer Registries (NPCR) and Surveillance, Epidemiology and End Results (SEER) for the period 2001-2017. Age-adjusted incidence and annual percent change (APC) were calculated in a step-wise manner to examine the trends among each of four US regions, followed by 13 individual SEER-reported states. SEER Stat software was used to analyze the data. Results: The incidence rates of AC in population >50 years have significantly increased in all US regions, with the lowest rates of increased incidence in the West with APC of 1.8 (CI: 1.2, 2.3) (table 1). While incidence rates of AC in population < 50 years have remained stable, a significant decrease was observed in the West region with an APC -2.2 (CI: -3.3, -1.1). When examining incidence rates of AC in population >50 years by states, the rates have increased significantly in all 13 SEER-reported states except New Mexico and Utah with the highest increase in Iowa with APC 4.2 (CI: 2.7, 5.8) (table 2). While there is an upward trend in population < 50 years, Kentucky and Louisiana demonstrated the largest increase in incidence, APC 4.0 (CI: 1.5, 6.5) and 2.6 (CI: 0.3, 4.9). Only California demonstrated a significant decrease in incidence in population < 50 years with an APC -2.5 (CI: -3.5, -1.4). Discussion: This study illustrates troubling increasing incidence of AC nationwide and noteworthy discrepancies of AC incidence rates by geographic location. Further efforts should focus on widespread adoption of public health preventive, screening, and surveillance strategies broadly across the country to impact the troubling rising incidence of AC. Public health organizations should closely examine the West region and the state of California to understand and adopt successful practices to mitigate rising rates of AC.
Disclosures: Anas Raed indicated no relevant financial relationships. Mahima Zandu indicated no relevant financial relationships. Amol Sharma indicated no relevant financial relationships. Humberto Sifuentes indicated no relevant financial relationships. Subbaramiah Sridhar indicated no relevant financial relationships.