Molecular prognostic factors in small-intestinal neuroendocrine tumours.

BACKGROUND: Small-intestinal neuroendocrine tumours (SI-NETs) represent a heterogeneous group of rare tumours. In recent years, basic research in SI-NETs has attempted to unravel the molecular events underlying SI-NET tumorigenesis. AIM: We aim to provide an overview of the current literature regarding prognostic and predictive molecular factors in patients with SI-NETs. METHOD: A PubMed search was conducted on (epi)genetic prognostic factors in SI-NETs from 2000 until 2019. RESULTS: The search yielded 1522 articles of which 20 reviews and 35 original studies were selected for further evaluation. SI-NETs are mutationally quiet tumours with a different genetic make-up compared to pancreatic NETs. Loss of heterozygosity at chromosome 18 is the most frequent genomic aberration (44-100%) followed by mutations of CDKN1B in 8%. Prognostic analyses were performed in 16 studies, of which 8 found a significant (epi)genetic association for survival or progression. Loss of heterozygosity at chromosome 18, gains of chromosome 4, 5, 7, 14 and 20p, copy gain of the SRC gene and low expression of RASSF1A and P16 were associated with poorer survival. In comparison with genetic mutations, epigenetic alterations are significantly more common in SI-NETs and may represent more promising targets in the treatment of SI-NETs. CONCLUSION: SI-NETs are mutationally silent tumours. No biomarkers have been identified yet that can easily be adopted into current clinical decision making. SI-NETs may represent a heterogeneous disease and larger international studies are warranted to translate molecular findings into precision oncology.

Clinical benefit of systemic treatment in patients with advanced pancreatic and gastrointestinal neuroendocrine tumours according to ESMO-MCBS and ASCO framework.

Background: Assessment of clinical benefit of systemic treatments of rare diseases including gastroenteropancreatic neuroendocrine tumours (GEP-NET) is challenging. Recently several tools have been developed to grade the clinical benefit of cancer drugs. The European Society for Medical Oncology (ESMO) has developed the ESMO Magnitude of Clinical Benefit Scale (ESMO-MCBS). The American Society of Clinical Oncology (ASCO) has developed and revised the ASCO framework consisting of the Net Health Benefit (NHB) score juxtaposed against the costs of the treatment. In this review, we graded systemic treatments for GEP-NET patients with both frameworks. Methods: The electronic databases (PubMed and EMBASE) were searched for papers reporting comparative trials, conducted in adult GEP-NET patients in the English language. Papers were assessed according to the ESMO-MCBS and the NHB part of the ASCO revised Framework (NHB-ASCO-F) by four independent assessors, and discrepancies were discussed. Results: The search yielded 32 trials of which 6 were eligible for grading with the ESMO-MCBS resulting in scores of 2 or 3. Eight trials were eligible for grading with the NHB-ASCO-F, resulting in scores between 37.6 and 57.4. Trials that were not primary assessable by the tools were analysed separately. Consensus between assessors was reached in 68% of trials with the ESMO-MCBS and in 23% of trials with the NHB-ASCO-F. Conclusion: The currently used systemic treatments for GEP-NET patients had low scores according to the NHB-ASCO-F and none could be graded as meaningful clinical beneficial according to the ESMO-MCBS. Despite the low incidence, the heterogeneous patient population and relatively long natural course of NET, future studies on new treatment modalities should aim for high clinical benefit outcomes.

Efficacy of isolated limb perfusion (ILP) in patients with Merkel cell carcinoma (MCC): A multicenter experience.

BACKGROUND: Merkel cell carcinoma (MCC) is a rare and potentially aggressive neuroendocrine tumor of the skin, with a propensity for locoregional metastases. In two expert referral centers, isolated limb perfusion (ILP) is used to obtain locoregional control in selected locoregionally advanced MCC patients. This study describes our experience. METHOD: Patients who underwent ILP for MCC were analyzed. ILP was performed with melphalan and tumor necrosis factor (TNF) combination therapy. Depending on the institution, either a normothermic or a hyperthermic temperature regimen was used. Baseline characteristics, toxicity data, locoregional progression-free survival (LPFS) and overall survival (OS) were assessed. RESULTS: Four males and 6 females with a median age of 78 years (IQR 61-84 years) were included. Four patients underwent ILP for upper extremity disease and 6 for lower extremity disease. All patients received combination therapy with Melphalan and TNF, one patient with the addition of interferon-gamma. No signs of systemic toxicity were present post-ILP. Severe locoregional toxicity (compartment syndrome) occurred in 1 patient and 1 elderly patient with extensive atherosclerosis had to undergo transfemoral amputation due to critical ischemia. Eight patients could be included for response evaluation. The overall response rate (ORR) was 87.5% with a complete response (CR) rate of 62.5%. Two long-term responses of 53 months and 71 months were observed. Median LPFS was 5 months and median OS was 54 months. CONCLUSION: ILP shows a high CR rate that can be durable. Therefore, ILP should be considered an effective treatment modality for locally advanced MCC.