Epidemiology and Prognosis factors of primary GI melanoma in the past decade: Results from the SEER database

Abstract Purpose: The purpose of this study is to investigate the clinical characteristics, survival outcomes, and independent prognostic factors of patients with primary GI melanoma in the past decade alone. Methods: A total of 399 patients diagnosed with Primary GI melanoma, between 2008 and 2017, were ultimately enrolled in our study by retrieving the Surveillance, Epidemiology, and End Results (SEER) database. We analyzed demographics, clinical characteristics, and overall mortality (OM) as well as cancer-specific mortality (CSM) of primary GI melanoma. Variables with a p value < 0.1 in the univariate Cox regression were incorporated into the multivariate Cox model to determine the independent prognostic factors, with a hazard ratio (HR) of greater than 1 representing adverse prognostic factors. Results: Multivariate cox proportional hazard regression analyses revealed higher OM in age group 80+ (HR = 5.653, 95% CI 2.212 - 14.445, p=0), stomach location of the tumor (HR = 2.821, 95% CI 1.265 - 6.292, p = 0.011), and distant metastases (HR= 4.491, 95% CI 3.115-6.476, p=0). Multivariate cox proportional hazard regression analyses of CSM also revealed higher mortality of the same groups. Conclusion: In this population-based retrospective cohort study using the SEER database, we found that age at diagnosis, the primary site of the disease, and advanced disease at diagnosis were independent factors predicting poor prognosis. Furthermore, even surgical resection and marital status did not significantly impact the overall mortality or the cancer-specific mortality.