Pancreatic metastases in patients with neuroendocrine neoplasms: A multi‐centre cohort study

Abstract

Pancreatic metastases (PMs) from neuroendocrine neoplasms (NENs) are rare but the increased sensitivity of new diagnostic tools such as 68 Ga-DOTATATE PET/CT has resulted in their increased recognition at initial diagnosis or follow-up.A retrospective analysis of the data of patients from six tertiary referral centres was performed in order to identify the characteristics and the prognostic significance of PMs in patients with NENs. We used a control group of 69 age-, sexand primary tumourmatched NEN patients from the same cohort with stage IV disease but no PMs. Overall survival (OS) was assessed using the Kaplan-Meier method log-rank analysis was used to assess the impact of various clinical and histopathological variables in OS. We identified 25 patients (11 females) with PMs with a median age at diagnosis of 60 years. The small intestine was the most common primary (80%) with a prevalence of 4.2% PMs (21/506). Fourteen patients presented with synchronous PMs whereas 11 developed metachronous PMs after a median time of 28 months (range: 7-168 months). Grading was available in 24 patients; 16 patients had G1 tumours, four G2, two atypical lung carcinoid, one typical and one atypical thymic carcinoid. Most patients had other concomitant metastases (12 hepatic, 4 lung and 6 bone) while five patients exhibited peritoneal carcinomatosis. Median OS in the PMs group was not reached compared with 212 months in the control group (95% CI: 26-398). The univariate analysis identified no prognostic factors statistically significantly associated with the OS. In conclusion, PMs are encountered with a low prevalence among NEN patients mostly developing in patients with advanced metastatic disease. The presence of PMs does not seem to be associated with a negative prognostic impact in OS.

Prevalence of metastases outside the liver and abdominal lymph nodes on 68Ga‐DOTATOC‐PET/CT in patients with small intestinal and pancreatic neuroendocrine tumours

“…11 To date, comprehensive descriptive and survival analyses in patients with rare metastases are sparse. 3,7,8,13,20,24 Of note, earlier studies have reported significantly shorter OS for patients with bone metastases, as compared to patients with other types of distant metastases. 3,10 The prevalence of Virchow's lymph node metastasis among patients with abdominal and thoracic malignancies has previously been estimated to be up to 2.8%.…”

“…Orbital lesions show low prevalence and are more commonly associated with Si-NET than Pan-NET, 5,13,14 which was confirmed by Interestingly, in a recent study in patients with Si-NET, pancreatic metastases had no impact on OS, when compared to matched controls. 8 Pan-NETs and Si-NETs both represent heterogeneous diseases, displaying a variable behaviour from a spectrum of relatively indolent to highly aggressive. These tumours, originating from different locations, indeed display many differences also from a molecular point of view, as they are related to different genetic or hormone-derived syndromes, display different driver alterations, and often display a wide spectrum of outcomes.…”

“…22,23 In two previous studies, the prevalence of Virchow's lymph node metastasis was 3%-4% in Si-NET and Pan-NET patients, but it was not associated with worse prognosis. 7,8 Finally, the presence of synchronous tumour deposits in both the small intestine and pancreas has been reported. In about one-third of the patients, two different primary tumours were identified according to the histopathological report after surgical resection.…”

“…1,2 Other, less common metastatic sites are bone, orbita, breast, heart, Virchow's lymph node, and, in Si-NET patients, pancreas. [3][4][5][6][7][8] Somatostatin receptor imaging (SRI) is well established as part of tumour staging at the time of NET diagnosis, as well as for restaging and to determine the tumour somatostatin receptor status when peptide receptor radionuclide therapy (PRRT) is considered. 1,9 Most Si-NET and Pan-NET of grade 1 (G1) and grade 2 (G2), express an abundance of somatostatin receptors (SST).…”

“…Small intestinal neuroendocrine tumours (Si‐NET) and pancreatic NET (Pan‐NET) are often diagnosed at stage IV, most commonly with metastases to abdominal/retroperitoneal lymph nodes and liver 1,2 . Other, less common metastatic sites are bone, orbita, breast, heart, Virchow's lymph node, and, in Si‐NET patients, pancreas 3–8 …”