Mixed neuroendocrine non-neuroendocrine neoplasms (MiNENs) represent a rare diagnosis of the gastro-entero-pancreatic tract. Evidence from the current literature regarding their epidemiology, biology, and management is of variable quality and conflicting. Based on available data, the MiNEN has an aggressive biological behaviour, mostly driven by its (often high-grade) neuroendocrine component, and a dismal prognosis. In most cases, the non-neuroendocrine component is of adenocarcinoma histology. Due to limitations in diagnostic methods and poor awareness within the scientific community, the incidence of MiNENs may be underestimated. In the absence of data from clinical trials, MiNENs are commonly treated according to the standard of care for pure neuroendocrine carcinomas or adenocarcinomas from the same sites of origin, based on the assumption of a biological similarity to their pure counterparts. However, little is known about the molecular aberrations of MiNENs, and their pathogenesis remains controversial; molecular/genetic studies conducted so far point towards a common monoclonal origin of the two components. In addition, mutations in tumour-associated genes, including TP53, BRAF, and KRAS, and microsatellite instability have emerged as potential drivers of MiNENs. This systematic review (91 full manuscripts or abstracts in English language) summarises the current reported literature on clinical, pathological, survival, and molecular/genetic data on MiNENs.

Background: Appendix goblet cell carcinoids are known to share histological features of adenocarcinoma and neuroendocrine tumours. Due to their low incidence, quality evidence is lacking for the management of these patients. Methods: We performed a single-centre retrospective study of patients with a confirmed diagnosis of appendiceal goblet cell carcinoid (GCC; 1996-2014). Patients were divided into curative intent (CI) and palliative intent (PI) cohorts. Our primary end point was overall survival (OS). Results: Seventy-four patients were eligible; 76% were treated with CI [surgery only (36%), cytoreductive surgery (CRS) and hyperthermic intra-peritoneal chemotherapy (HIPEC; 36%), adjuvant chemotherapy (20%) and a combination of CRS and HIPEC followed by adjuvant chemotherapy (9%)], and 23% had advanced-stage disease amenable to palliative treatment (chemotherapy or supportive care) only. Completion right hemicolectomy, performed in 64% of the CI cohort, did not impact on the relapse rate or disease-free survival. FOLFOX chemotherapy was used in both the adjuvant and palliative settings; safety was as expected, and we observed a high rate (60%) of disease control in the palliative cohort. The estimated median OS (all patients), disease-free survival (CI patients) and progression-free survival (PI patients) were 52.1 (95% CI 29.4-90.3), 75.9 (26.6-not reached) and 5.3 (0.6-5.7) months, respectively. Age and stage were independent factors associated with OS in the multivariable analysis. Tang classification showed a trend for impact on OS. No benefit from specific adjuvant approach was identified; however, selection bias for treatment approach was observed. Conclusion: Prospective trials are needed to define optimal approaches in GCC. All GCC patients should be managed by specialized centres due to their esoteric behaviour; we provide management considerations based on our experience and conclusions.

This study identified two LAMN subtypes. Type II lesions have pathological features of increased risk for dissemination and should be considered for risk-reducing cytoreductive surgery.

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BACKGROUNDMixed neuroendocrine non-neuroendocrine neoplasm (MiNEN) is a rare diagnosis, mainly encountered in the gastro-entero-pancreatic tract. There is limited knowledge of its epidemiology, prognosis and biology, and the best management for affected patients is still to be defined.AIMTo investigate clinical-pathological characteristics, treatment modalities and survival outcomes of a retrospective cohort of patients with a diagnosis of MiNEN.METHODSConsecutive patients with a histologically proven diagnosis of MiNEN were identified at 5 European centres. Patient data were retrospectively collected from medical records. Pathological samples were reviewed to ascertain compliance with the 2017 World Health Organisation definition of MiNEN. Tumour responses to systemic treatment were assessed according to the Response Evaluation Criteria in Solid Tumours 1.1. Kaplan-Meier analysis was applied to estimate survival outcomes. Associations between clinical-pathological characteristics and survival outcomes were explored using Log-rank test for equality of survivors functions (univariate) and Cox-regression analysis (multivariable).RESULTSSixty-nine consecutive patients identified; Median age at diagnosis: 64 years. Males: 63.8%. Localised disease (curable): 53.6%. Commonest sites of origin: colon-rectum (43.5%) and oesophagus/oesophagogastric junction (15.9%). The neuroendocrine component was; predominant in 58.6%, poorly differentiated in 86.3%, and large cell in 81.25%, of cases analysed. Most distant metastases analysed (73.4%) were occupied only by a poorly differentiated neuroendocrine component. Ninety-four percent of patients with localised disease underwent curative surgery; 53% also received perioperative treatment, most often in line with protocols for adenocarcinomas from the same sites of origin. Chemotherapy was offered to most patients (68.1%) with advanced disease, and followed protocols for pure neuroendocrine carcinomas or adenocarcinomas in equal proportion. In localised cases, median recurrence free survival (RFS); 14.0 mo (95%CI: 9.2-24.4), and median overall survival (OS): 28.6 mo (95%CI: 18.3-41.1). On univariate analysis, receipt of perioperative treatment (vs surgery alone) did not improve RFS (P = 0.375), or OS (P = 0.240). In advanced cases, median progression free survival (PFS); 5.6 mo (95%CI: 4.4-7.4), and median OS; 9.0 mo (95%CI: 5.2-13.4). On univariate analysis, receipt of palliative active treatment (vs best supportive care) prolonged PFS and OS (both, P < 0.001).CONCLUSIONMiNEN is most commonly driven by a poorly differentiated neuroendocrine component, and has poor prognosis. Advances in its biological understanding are needed to identify effective treatments and improve patient outcomes.

BackgroundThe extent of resistance to immune surveillance in patients with well-differentiated (Wd) (grade 1/2) small-intestinal neuroendocrine tumours (Si-NETs) is unknown.MethodsPatients diagnosed with Wd Si-NETs (excluding appendix, which are considered to have a different biology to other midgut NETs) were eligible. Tumoural programmed death (PD)-ligand(L) 1 (PD-L1)/PD-L2/PD-1 and tumour infiltrating lymphocytes (TILs) [presence and phenotype] were analysed in archival tissue by immunohistochemistry (IHC); reverse transcription quantitative polymerase chain reaction (RT-qPCR) was used for confirmation of IHC results.ResultsOf 109 patients screened, 62 were eligible: 54.8% were male; median age was 63.7 years (95%-CI 59.7-67.2); disease stage II: 4.8%, III: 40.3% and IV: 54.8%; 41.9% were functional. Analysed samples (67.1% from primary tumours, 32.9% from metastases) were of grade 1 (67.1%) or 2 (32.86%) with a median Ki-67 of 2%. From the total of 62 eligible patients, 70 and 63 samples were suitable for IHC and RT-qPCR analysis, respectively. PD-L1 expression within tumour cells and TILs were identified in 12.8% and 24.3% of samples respectively; 30% of samples showed PD-L1 expression within tumour cells and/or TILs. PD-1 was present in TILs in 22.8% of samples. Majority of samples showed significant presence of CD4+ (focal 42.86%; moderate 2.86%) and CD8+ (focal 92.86%; moderate 4.29%) TILs. IHC findings were confirmed with RT-qPCR; which showed higher expression levels of PD-L1 (p-value 0.007) and PD-1 (p-value 0.001) in samples positive for IHC compared to negative-IHC.ConclusionsThirty-percent of patients express PD-L1 within tumour cells and/or TILs. Identification of presence of TILs was also significant and warrant the investigation of immunotherapy in this setting.

This study quantifies the impact of cytoreductive surgery with hyperthermic intraperitoneal chemotherapy on overall and disease event-free survival for appendix adenocarcinoma, identifying key prognostic indicators that may guide treatment. It supports the referral of these rare tumors to specialist centers with appropriate expertise for initial management and follow-up. See Video Abstract at http://links.lww.com/DCR/A595.

ObjectivesTo assess the use of MRI-determined tumour regression grading (TRG) in local response assessment and detection of salvageable early local relapse after chemoradiotherapy (CRT) in patients with anal squamous cell carcinoma (ASCC).MethodsFrom a prospective database of patients with ASCC managed through a centralised multidisciplinary team, 74 patients who completed routine post-CRT 3- and 6-month MRIs (2009–2012) were reviewed. Two radiologists blinded to the outcomes consensus read and retrospectively assigned TRG scores [1 (complete response) to 5 (no response)] and related these to early local relapse (within 12 months) and disease-free survival (DFS).ResultsSeven patients had early local relapse. TRG 1/2 scores at 3 and 6 months had a 100 % negative predictive value; TRG 4/5 scores at 6 months had a 100 % positive predictive value. All seven patients underwent salvage R0 resections. We identified a novel ‘tram-track’ sign on MRI in over half of patients, with an NPV for early local relapse of 83 % at 6 months. No imaging characteristic or TRG score independently prognosticated for late relapse or 3-year DFS.ConclusionsPost-CRT 3- and 6-month MRI-determined TRG scores predicted salvageable R0 early local relapses in patients with ASCC, challenging current clinical guidelines.Key Points• Post-chemoradiotherapy MRI (3 and 6 months) helps local response assessment in ASCC.• The MRI-TRG system can be used reproducibly in patients with ASCC.• The TRG system facilitates patient selection for examination under anaesthesia and biopsy.• The use of MRI-TRG predicts for detection of salvageable early local relapses.• The TRG system allows for a standardised follow-up pathway.Electronic supplementary materialThe online version of this article (doi:10.1007/s00330-016-4337-z) contains supplementary material, which is available to authorized users.