Background/Aims: Gastroenteropancreatic (GEP) neuroendocrine carcinomas (NECs) are defined as neuroendocrine neoplasms (NENs) with a Ki-67 index >20% according to the 2010 WHO classification. Some reports suggest that this category is heterogeneous. We retrospectively studied a series of 136 patients affected by grade 3 GEP-NECs with the aim to clarify the prognostic role of tumor morphological differentiation, proliferation, defect in mismatch repair proteins (MMRd), CD117 expression, and site of origin. The primary endpoint was the correlation between these parameters and the overall survival (OS). Methods: Univariate and multivariable Cox proportional hazards regression analyses were used to assess the prognostic significance of various clinical and histopathologic features. Results: With a median follow-up of 81 months, the median OS was 12.9 months. At multivariate analysis, morphological differentiation, Ki-67 index, MMRd, stage, and CD117 expression were independent prognostic markers in NECs. Three different prognostic categories of NECs were identified according to the degree of morphologic differentiation (well vs. poorly differentiated) and Ki-67 index (<55% vs. ≥55%). On this basis, median OS was 43.6 months in well-differentiated neoplasms with a Ki-67 index 20-55% (named type A), 24.5 months in poorly differentiated neoplasms with a Ki-67 index 20-55% (type B), and 5.3 months (p < 0.0001) in poorly differentiated neoplasms with a Ki-67 index ≥55% (type C). Conclusions: The present study suggests that GEP-NECs represent a heterogeneous group of neoplasms which can be better classified in different prognostic categories using both tumor morphology and Ki-67 index.

Introduction: Lanreotide autogel (LAN) and temozolomide (TMZ) are guidelines-recommended monotherapies for thoracic neuroendocrine tumors (carcinoids; T-NETs), but prospective data for both combined and monotherapies are lacking. ATLANT (NCT02698410) evaluated efficacy and safety of LAN/TMZ in progressive T-NETs. Methods: ATLANT was a 12-month, Italian, phase 2, single-arm, open-label, multicenter pilot study. Eligible patients had unresectable, locally advanced/metastatic, well-/moderately differentiated T-NETs with radiological progression. Patients received subcutaneous LAN 120 mg every 28 days and oral TMZ 250 mg/day for 5 consecutive days every 28-day cycle. Main endpoints are disease control rate (DCR) at 9 months (primary; investigator-assessed), median progression-free survival (PFS), biomarkers, and safety. Results: The number of patients was 40; 60% were male. Primary tumor site was lung (90%) and thymus (10%). Carcinoid type was typical (20.0%) and atypical (52.5%). DCR at 9 months was 35.0% (95% confidence interval (CI) 20.63–51.68; nonacceptability threshold ≤10%, p < 0.0001; not significantly above clinically relevant threshold ≥30%, p = 0.2968). DCR between 7.5 and 10.5 months (sensitivity analysis) was 45.0% (95% CI: 29.26–61.51) and clinically relevant (p = 0.0320 at ≥30% threshold). Median PFS was 37.1 (95% CI: 24.1–52.9) weeks. No association was observed between biomarker variations (chromogranin A, neuron-specific enolase, somatostatin receptor type-2, Ki-67, 6-O-methylguanine-DNA-methyl-transferase) and DCR or PFS. Most patients (97.5%) had treatment-emergent adverse events (TEAEs); 72.5% had treatment-related TEAEs. TEAEs were mainly grade 1/2. No unanticipated TEAEs were reported. Conclusions: This study showed that the LAN/TMZ combination has promising efficacy in progressive T-NETs, and was well tolerated. Larger studies are warranted to support the clinical benefits of LAN/TMZ in patients with T-NETs.

Background: Broncho-pulmonary neuroendocrine tumors (bpNETs) are rare malignancies and there is no consensus on therapeutical management of metastatic disease and follow-up after radical resection. Methods: Clinical records of patients with a cytological or histological diagnosis of bpNETs and distant metastases (metachronous or synchronous), evaluated at the European Institute of Oncology between 1997 and 2014, were retrospectively analyzed. Data on patient demographics, pathology, imaging exams, surgical and non-surgical treatments were collected. P value descriptive data, uni- and multi-variate survival analysis were generated for all variables. Results: With a median follow-up of 53 [9–215] months, 61 patients with metachronous and 47 with synchronous metastases were analysed. The most common tool of first recurrence detection was computed tomography. Liver (67%), lymph node (25%), bone (22%) and lung (16%) were the most common sites of relapse. Median time to recurrence was 5 years. Median overall survival (OS) was 72 months for the whole population, with no significant difference between patients with synchronous and metachronous metastases. Age, bone metastases, liver metastases and Ki-67 as a continuous variable all significantly correlated with prognosis at the multivariate analysis. Conclusions: This is one of the largest, single-centre, series of metastatic bpNETs. Among patients with metachronous metastases the pattern of recurrences was heterogeneous as were the follow-up exams used to detect them. The results of our analysis may represent solid bases for designing prospective clinical trials in homogeneous settings of bpNETs.

Background: The success of targeted therapies in the treatment of pancreatic neuroendocrine tumors has emphasized the strategy of targeting angiogenesis and the PI3K/AKT/mTOR pathway. However, the major challenge in the targeted era remains the early identification of resistant tumors especially when the efficacy is rarely associated to a clear tumor shrinkage at by imaging assessment. Methods: In this prospective study (NCT02305810) we investigated the predictive and prognostic role of soluble biomarkers of angiogenesis turnover (VEGF, bFGF, VEGFR2, TSP-1) circulating endothelial cells and progenitors, in 43 patients with metastatic panNET receiving everolimus. Results: Among all tested biomarkers, we found a specific subpopulation of circulating cells, CD31+CD140b-, with a significantly increased tumor progression hazard for values less or equal to the first quartile. Conclusion: Our study suggested the evidence that circulating cells might be surrogate biomarkers of angiogenesis activity in patients treated with everolimus and their baseline levels can be correlated with survival. However, further studies are now needed to validate the role of these cells as surrogate markers for the selection of patients to be candidates for antiangiogenic treatments.

Merkel cell carcinoma (MCC) is a very rare and aggressive neuroendocrine carcinoma originating from Merkel cells, typically with a skin nodule; however, it exceptionally presents with only a basin lymph node localization, with neither a cutaneous primary site nor distant metastases. From 1996 to 2020, among patients with histologically confirmed MCC managed at a neuroendocrine neoplasm-referral center, we selected those with an exclusive nodal basin, no distant metastasis, and an unknown primary site defined by cross-sectional and physical examination. A total of 55 out of 310 patients fulfilled the selection criteria. The median age was 64 years and the majority were males. Inguinal lymph-nodes were the most common anatomic site. With a median follow-up of 4.3 years, the 5-year relapse-free survival (RFS) rate was 56.6 (95% CI 42.0–68.8%) and the 5-year cancer specific survival (CSS) rate was 68.5 (95% CI 52.8–79.9%) for the whole population. The 36 patients (65.5%) undergoing lymphadenectomy (LND) + radiotherapy (RT) ± chemotherapy had a 5-year RFS rate of 87.2% (95% CI 65.5–95.7%) and a 5-year CSS rate of 90.5% (95% CI 67.0–97.5), which were better than those receiving LND alone. In a multivariable analysis, the survival benefit for LND + RT remained significant. Results from one of the largest single-center series of nMCC-UP suggest that a curative approach including RT can be effective, similar to what is observed for stage IIIB MCC. Multicentric studies with homogenous populations should be carried out in this controversial clinical entity, to minimize the risk of biases and provide robust data.