Metastasis patterns and racial disparities in gastrointestinal cancers: A SEER database population study 2010–2018.

Abstract

3597 Background: Metastatic disease at the time of diagnosis of gastrointestinal (GI) malignancies is a strong predictor of poor outcomes. Differences in metastatic patterns among Caucasians (C) and African-Americans (AA) needs further elucidation. In this study, we analyzed the patterns of metastasis in C and AA in colorectal cancer (CRC), pancreatic cancer (PC), gastric cancer (GC), and liver cancer (LC). Methods: We identified patients with CRC, PC, GC, and LC from the Surveillance, Epidemiology, and End Results Program (SEER) database from 2010-2018. We obtained metastasis data to lungs, liver, bone, and brain at the time of diagnosis. We calculated the relative risk (RR), confidence interval (CI), and standard error with the use of SPSS software, 28.0 (IBM). Results: The most common metastasis site was the liver being highest at 39% in AA with PC. Brain metastasis was the least common. Significant racial disparities were noted. In CRC, AA had a 35-37% increased risk of metastasis to the liver, lung, or bone. AA had a higher risk of liver metastasis in PC and GC, whereas C had a higher risk of lung metastasis. Table 1 summarizes the data findings. Conclusions: This study illustrates the disparities of metastasis from GI cancers among AA and C. While a delay in screening, earlier onset of CRC in AA and socioeconomic factors may explain the disparities witnessed in CRC. However, these factors will fail to explain the difference in metastasis pattern in PC and GC in that AA had a higher risk of liver metastasis, and C had a higher risk of lung metastasis. Moreover, In GC, the brain metastasis rate in C was double that of AA. Further studies of possible biological and other risk factors are needed. [Table: see text]