Preoperative anemia: impact on short- and long-term outcomes following curative-intent resection of gastroenteropancreatic neuroendocrine tumors

Abstract

ObjectiveThe impact of preoperative anemia on clinical outcomes of patients undergoing resection of gastro-entero-pancreatic neuroendocrine tumors (GEP-NETs) has not been previously investigated. The objective of the current study was to characterize how preoperative anemia affected short- and long-term outcomes of patients undergoing curative-intent resection of GEP-NETs. MethodsPatients who underwent curative-intent resection for GEP-NETs between January 1990 to December 2020 were identified from eight major institutions. The last preoperative hemoglobin level was recorded; anemia was defined as < 13.5g/dl in males or < 12.0g/dl in females based on instructions of American Society of Hematology. The impact of anemia on post-operative outcomes were assessed on uni- and multivariate analysis. ResultsAmong1,559 patients, median age was 58 years (IQR 48-66) and roughly one-half of the cohort was male (n=796, 51.1%). Most patients had a pancreatic tumor (n=1040, 66.7%), followed by small bowel (n=259, 16.6%), duodenum (n=103, 6.6%), stomach (n=66, 4.2%), appendix (n=53, 3.4%), and other locations (n=38, 2.6%). Median preoperative hemoglobin level was 13.4 (IQR 12.2-14.5) g/dl. Overall, 101 (6.7%) and 119 (8.5%) patients received an intra- or postoperative pRBC transfusion, respectively. A total of 972 (44.5%) patients experienced a postoperative complication. Although the overall incidence of complications was no different among patients who did (anemic 48.7%) versus did not (non-anemic 47.3%) have anemia (p=0.597), patients with preoperative anemia were more likely to develop a major (≥Clavien-Dindo grade IIIa: anemic 48.9% vs. non-anemic 38.0%, p=0.006) and multiple (≥3 types of complications: anemic 32.2% vs. anemic 19.7%, p<0.001) complications. 1-, 3-, and 5-year overall survival (OS) was 96.7%, 90.5%, and 86.6% respectively. On multivariable analysis, anemia (HR 2.0, 95% CI 1.2-3.2, p=0.006) remained associated with worse OS; postoperative pRBC transfusion was associated with a OS (5-year OS, 75.0% vs. 87.7%, p=0.017), as well as RFS (5-year RFS, 66.9% vs. 76.5%, p=0.047). Conclusionspreoperative anemia was commonly identified in roughly 1 in 3 patients who underwent curative-intent resection for GEP-NETs. Preoperative anemia was strongly associated with higher risk of postoperative morbidity and worse long-term outcomes.