Epidemiological Data and Treatment of Gastroenteropancreatic Neuroendocrine Neoplasms: Insights From Tertiary Referral Hospitals in Latvia

BACKGROUND: Gastroenteropancreatic neuroendocrine neoplasms (GEP-NEN) are rare, heterogeneous group which tend to rise in incidence. Epidemiological profile and outcomes of GEP-NEN may vary among countries. The aim of study was to provide baseline clinical and histopathological features of patients with GEP-NEN from tertiary referral hospitals in Latvia.

METHODS: A retrospective study of patients with histologically confirmed diagnosis of GEP-NEN treated between 2006 and 2018. Joinpoint regression modeling was used to estimate annual percentage change (APC) for incidence trends. Overall survival (OS) rate was obtained by Kaplan-Meier method.

RESULTS: In total, 205 patients were included. The median age at diagnosis was 61.0 (IQR 52.0-70.5) years, 69.3% were females. The age-adjusted incidence per 100 000 inhabitants increased from 0.03 in 2006 to 0.67 in 2018 with APC of 24.1%, p < 0.005. The most common primary tumor site was pancreas (30.7%), followed by stomach (24.9%) and small intestine (20.5%). Non-functional tumors are present in 83.4%, while carcinoid syndrome in 7.8%. Stage IV metastatic disease was present in 27.8% tumors. The majority of patients (82%) received an operation with radical or palliative intent. The 1- and 3-year OS rate were 88.0% (95% CI 83.3-92.7) and 77.1% (95% CI 70.4-83.8), respectively. Increasing tumor grade, stage and the presence of distant metastases were associated with significantly worse OS.

CONCLUSION: Our study highlights increasing incidence of GEP-NEN in Latvia. The most common primary site was pancreas and surgery considered as main modality of treatment. Registry and long-term data collection are necessary to develop GEP-NEN management concept in Latvia.