A retrospective review of diagnosis and treatment modalities of neuroendocrine tumors (excluding primary lung cancer) in 10 oncological institutions of the East German Study Group of Hematology and Oncology (OSHO), 2010-2012.

RATIONALE: There is a paucity of data on the incidence of neuroendocrine tumors (NET) outside pulmonary primaries and on treatment modalities applied to patients with NET in clinical practice. Only very little therapeutic progress has been made with respect to response and overall survival, particularly among patients with poorly differentiated, WHO grade 3 neuroendocrine carcinomas (G3-NEC). We sought to document the incidence and treatment modalities in patients with NET/NEC within a period of 2 years.
METHODS: We conducted a retrospective data analysis using a simple documentation file to be completed in written form or electronically, including localization, WHO grading, treatment modalities, and specific therapeutic regimens applied. Primary lung cancer was excluded. The time period to be covered was 2010 through 2012. Individual patient data such as names or age were not documented, so that no ethics committee approval was required.
RESULTS: Ten different hospital- or practice-based institutions contributed their data. One to 35 patients were documented per institution, summing up to 149 patients with 154 tumor localizations. Midgut (n = 46), foregut (n = 42), hindgut (n = 17), lung (n = 9), bladder (n = 8), unknown primary (n = 11), and other including prostate and liver (n = 21) were documented as tumor sites. Histological gradings were G1 (n = 71), G2 (n = 27), G3 (n = 34), undifferentiated "G4" (n = 4), and not specified (n = 13). Treatment modalities were surgical resection (n = 102), chemotherapy (n = 49), somatostatin analogs (n = 39), radiotherapy (n = 22), receptor-directed radionuclide therapy (n = 12), and systemic tyrosine kinase inhibition (n = 5). Chemotherapy was given to patients not only with G3-NEC (n = 31), but also with G2 (n = 12) and G1 NET (n = 7). Somatostatin analogs as well as receptor-directed radionuclides were applied to patients throughout all gradings.
CONCLUSIONS: NET and NEC are not very rare tumor entities, but are diagnosed with very different frequencies, possibly depending upon the alertness of pathologists and clinicians. Chemotherapy, receptor-directed radionuclide application, and somatostatin analog therapy are applied without a clear correlation to different histologic gradings. Diagnostic and therapeutic progress in the field of NETs/carcinomas is urgently needed.