Clinicopathological characteristics and prognostic factors of elderly small intestine adenocarcinoma using propensity score matching analysis: a study based on SEER database

Background Small intestine adenocarcinoma (SIA) is a scant disease that has no adequate clinical trials, so its prognostic factors are still unclear, especially in elderly patients. In this article, we aimed to explore the clinicopathology presentation, treatments, outcomes, and predictors of small intestine adenocarcinoma patients aged 65 years or older. Methods We retrieved clinicopathology data of small intestine adenocarcinoma patients diagnosed between 2004 and 2015 from the Surveillance Epidemiology and End Results (SEER) database. We clarified patients into two groups: the surgery and the non-surgery group and conducted propensity score matching (PSM) to compare survival outcoming. We identified the prognostic indicators for cancer-specific survival (CSS) and overall survival (OS) by the Cox proportional hazards model. Results In total, 1018 eligible cases were enrolled, with a median survival of 16 months; the 3-year OS and CSS rates were 36% and 41.7%, and the 5-year OS and CSS rates were 26.5% and 33.3%. Multivariate analyses revealed that age, grade, tumor stage, surgery, and chemotherapy were independent prognostic factors for OS, while grade, tumor stage, surgery, radiation, and chemotherapy were independent factors for CSS. After PSM, only surgery and tumor stage (AJCC 6th) were independent prognostic factors for OS and CSS. Conclusion Surgery could bring benefit to survival for elderly SIA patients, and the early stage of the disease was another significant prognostic factor.