Nutrition and neuroendocrine tumors: An update of the literature

Nutritional status and gastroenteropancreatic neuroendocrine neoplasms: lights and shadows with a clinical guide from the NIKE Group

Neuroendocrine neoplasms (NENs) originating in the gastroenteropancreatic (GEP) tract are rare tumors often associated with significant metabolic disturbances and nutritional challenges. This review explores the intricate relationship between nutritional status and the development, progression, and prognosis of GEP-NENs. Through an extensive literature search encompassing studies up to April 2024, we examined various factors, including obesity, malnutrition, metabolic syndrome and type 2 diabetes mellitus, and their roles in the development and progression of GEP-NENs. The review highlights the dual role of obesity, both as a risk factor and a potential prognostic indicator, drawing attention to the 'obesity paradox' observed in cancer research. Additionally, we discuss the impact of malnutrition on patient outcomes and emphasize the need for comprehensive nutritional assessments beyond BMI. This analysis highlights the importance of incorporating nutritional interventions into preventive and therapeutic strategies for GEP-NEN patients. Future research should further clarify these associations and develop personalized nutritional management protocols to improve patient prognosis and quality of life. Acronyms adopted in the text and tables: AOR: adjusted odd ratio, BIA: Bioelectrical Impedance Analysis, BMI: Body Mass Index, CI: confidence interval, CLARINET: Controlled Study of Lanreotide Antiproliferative Response in Neuroendocrine Tumor, FLI: fatty liver index, GEP: gastroenteropancreatic, GLIM: global leadership into malnutrition, HR: hazard ratio, MS: metabolic syndrome, MUST: malabsorption universal screening tool, NEC: neuroendocrine carcinoma, NENs: Neuroendocrine neoplasms, NETs: Neuroendocrine tumors, NRS: Nutritional Risk Screening, OR: odd ratio, OS: overall survival, PFS: progression-free survival, RR: risk ratio, SGA: Subjective Global Assessment, T2DM: type 2 diabetes mellitus, VAI: visceral adiposity index, WD: well-differentiated.

Nutritional status and quality of life of patients with advanced gastroenteropancreatic neuroendocrine neoplasms in Spain: the NUTRIGETNE (GETNE-S2109) study

Patients with advanced gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) have impaired nutritional and physical performance due to the cancer pathophysiology and its treatment. The NUTRIGETNE study sought to characterize the nutritional status of patients with advanced GEP-NENs in Spain. This is a cross-sectional study that included patients with advanced GEP-NENs receiving active oncological treatment. Patients had a complete physical examination, anthropometry, bioelectrical impedance, dynamometry, laboratory analysis, and a comprehensive nutritional risk assessment. Malnutrition was defined according to Global Leadership Initiative on Malnutrition (GLIM) criteria. The study included 399 patients out of the 400 planned (Pearson's χ2; α 0.05). Median age was 62 years (22-83). Tumors most commonly originated in the small intestine (43.9%) and the pancreas (41.6%), 94.7% were metastatic, and 36.7%, 49.4%, and 12.5% were G1, G2, and G3, respectively. Malnutrition prevalence was 61.9% (25.8% moderate; 36.1% severe), mainly due to low muscle mass (50.9%), which was the most prevalent GLIM phenotypic criteria. Moreover, malnutrition showed a correlation with decreased hand grip strength (mean 23 vs 31.9 kg; P <.001) and phase angle (median 5o vs 5.6o; P <.001). The prevalence of sarcopenia was 15%. Malnutrition was more frequent in patients with diabetes (74.4% vs 56.7%; P <.001), NECs (82.1% vs 60.3%; P =.062), and in those treated with chemotherapy (71.2% vs 59.7%; P =.058), whereas it did not correlate with tumor origin (P =.507), histological grade (P =.781), or functionality (P =.465). Malnutrition was correlated to body mass index (BMI) (P =.015), although it was also diagnosed in a high proportion of patients with no weight loss (63%, 54.1%, and 65.1% of patients with normal BMI, overweight, and obesity, respectively). Cachexia was present in 109 (27.3%) patients. Malnutrition is very prevalent and commonly underdiagnosed in patients with GEP-NENs. It is associated with sarcopenia and a worse QoL, requiring a multifactorial nutritional assessment. Certain factors such as the presence of diabetes may require closer monitoring due to a higher risk of malnutrition.

Nutritional aspects in neuroendocrine neoplasms. bridging the gap between dietary interventions and cancer care strategies: a scoping review

PURPOSE

Neuroendocrine neoplasms (NENs) represent heterogeneous tumors arising from neuroendocrine cells in different organs. Despite growing interest in the nutritional aspects of NEN management, research in this area is limited. Aim of this review is to summarize the current state of knowledge, highlight research gaps, and underscore the significance of nutrition in the comprehensive care of NEN patients.

METHODS

We conducted an extensive bibliographic search focusing on studies (including retrospective and prospective studies, systematic reviews, case series, and guidelines) exploring the relationship between nutritional assessments, dietary interventions, micronutrient deficiencies, and their impact on NEN outcomes.

RESULTS

Significant gaps exist in current research, particularly in understanding the specific nutritional needs of NEN patients and how tailored nutritional interventions can improve clinical outcomes. Evidence suggests that a high-fat Western diet may promote the growth of NEN, while a Mediterranean diet may help lower insulin levels and strengthen the immune system, potentially preventing tumor development. The ketogenic diet and intermittent fasting may also have positive impacts. Addressing common micronutrient deficiencies, such as vitamin D and niacin, is crucial to mitigate disease progression. There's a crucial need for future studies to include a comprehensive nutritional assessment incorporating patient-reported outcomes, to fully capture the impact of nutritional strategies.

CONCLUSION

Nutritional management, an important but under-researched facet of NEN treatment, significantly improves patients' quality of life and survival. Integrating nutrition into personalized cancer care is essential, highlighting the role of nutritional strategies in optimizing patient outcomes.

Gastroenteropancreatic neuroendocrine neoplasms: current development, challenges, and clinical perspectives

Neuroendocrine neoplasms (NENs) are highly heterogeneous and potentially malignant tumors arising from secretory cells of the neuroendocrine system. Gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) are the most common subtype of NENs. Historically, GEP-NENs have been regarded as infrequent and slow-growing malignancies; however, recent data have demonstrated that the worldwide prevalence and incidence of GEP-NENs have increased exponentially over the last three decades. In addition, an increasing number of studies have proven that GEP-NENs result in a limited life expectancy. These findings suggested that the natural biology of GEP-NENs is more aggressive than commonly assumed. Therefore, there is an urgent need for advanced researches focusing on the diagnosis and management of patients with GEP-NENs. In this review, we have summarized the limitations and recent advancements in our comprehension of the epidemiology, clinical presentations, pathology, molecular biology, diagnosis, and treatment of GEP-NETs to identify factors contributing to delays in diagnosis and timely treatment of these patients.

Role of Mediterranean diet in endocrine diseases: a joint overview by the endocrinologist and the nutritionist

PURPOSE

The purpose of this review is to examine the current evidence on the potential role of Mediterranean diet (MD) in the prevention and management of endocrine disorders and to highlight the importance of interdisciplinary collaboration between endocrinologists and nutritionists.

METHODS

A literature search was conducted using PubMed and Google Scholar databases to identify relevant studies published in English. Studies were selected based on their relevance to the role of MD in the prevention and management of endocrine disorders. The search terms included "Mediterranean diet," "endocrine disorders," "thyroid disorders," "gonadal disorders," and "neuroendocrine tumors".

RESULTS

The studies reviewed suggest that MD may have a beneficial effect in the prevention and management of various endocrine disorders, including thyroid disorders, gonadal disorders, and neuroendocrine tumors. MD has been associated with decreased risk of nodular thyroid disease and thyroid cancer, improved male and female reproductive health, and a potential role in the management of neuroendocrine tumors. MD's anti-inflammatory and antioxidant properties, as well as its high levels of phytochemicals, may play a role in its beneficial effects.

CONCLUSION

Interdisciplinary collaboration between endocrinologists and nutritionists is essential for the optimal management of endocrine disorders, including the potential role of MD in their prevention and management. While further research is needed, the current evidence suggests that MD may have a protective effect against endocrine disorders, and its incorporation into dietary recommendations may be beneficial.

Low Prognostic Nutritional Index Is Common and Associated with Poor Outcomes following Curative-Intent Resection for Gastro-Entero-Pancreatic Neuroendocrine Tumors

INTRODUCTION

To investigate the impact of prognostic nutritional index (PNI) on short- and long-term outcomes of patients who underwent curative-intent resection for gastro-entero-pancreatic neuroendocrine tumors (GEP-NETs).

METHODS

Patients with GET-NETs who underwent curative-intent resection were identified from a multi-center database. The prognostic impact of clinicopathological factors including PNI on post-operative outcomes were evaluated. A novel nomogram was developed and externally validated.

RESULTS

A total of 2,099 patients with GEP-NETs were included in the training cohort; 255 patients were in the external validation cohort. Median PNI (n = 973) was 47.4 (IQR 43.1-52.4). At the time of presentation, 1,299 (61.9%) patients presented with some type of clinical symptom. Low-PNI (≤42.2) was associated with gastrointestinal symptoms, as well as nodal metastasis and distant metastasis (all p < 0.05). Patients with a low PNI had a higher incidence of severe (≥Clavien-Dindo grade IIIa: low PNI 24.9% vs. high PNI 15.4%, p = 0.001) and multiple (≥3 types of complications: low PNI 14.5% vs. high PNI 9.2%, p = 0.024) complications, as well as a worse overall survival (OS)(5-year OS, low PNI 73.7% vs. high PNI 88.5%, p < 0.001), and RFS (5-year RFS, low PNI 68.5% vs. high PNI 79.8%, p = 0.008) versus patients with high PNI (>42.2). A nomogram based on PNI, tumor grade and metastatic disease demonstrated excellent discrimination and calibration to predict OS in both the training (C-index 0.748) and two external validation (C-index 0.827, 0.745) cohorts.

CONCLUSIONS

Low PNI was common and associated with worse short- and long-term outcomes among patients with GEP-NETs.

Consideration of quality-of-life in the treatment decision-making for patients with advanced gastroenteropancreatic neuroendocrine tumors

INTRODUCTION

Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are a complex and heterogenous family of solid malignancies that originate from neuroendocrine tissue in the gastrointestinal tract or pancreas. Most patients diagnosed with GEP-NETs present with advanced or metastatic disease, and quality of life (QoL) is often an important priority when selecting treatments for these patients. Patients with advanced GEP-NETs often experience a substantial and persistent symptom burden that undermines their QoL. Addressing a patient's individual symptoms through judicious selection of treatment may improve QoL.

AREAS COVERED

The objectives of this narrative review are to summarize the impact of advanced GEP-NETs on patient QoL, assess the potential value of current treatments for maintaining or improving patient QoL, and offer a clinical framework for how these QoL data can be translated to inform clinical decision-making for patients with advanced GEP-NETs.

EXPERT OPINION

Patients with advanced GEP-NETs experience a significant and persistent symptom burden that impacts their daily lifestyle, activities, work life, and financial health, leading to erosion of their QoL. Ongoing and future studies incorporating longitudinal QoL assessments and head-to-head treatment evaluations will further inform the incorporation of QoL into clinical decision-making.

Impact of Change in Body Composition during Follow-Up on the Survival of GEP-NET

Background: Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are heterogeneous rare diseases causing malnutrition and cachexia in which the study of body composition may have an impact in prognosis. Aim: Evaluation of muscle and fat tissues by computed tomography (CT) at the level of the third lumbar (L3 level) at diagnosis and at the end of follow-up in GET-NET patients and their relationships with clinical and biochemical variables as predictors of survival. Methodology: Ninety-eight GEP-NET patients were included. Clinical and biochemical parameters were evaluated. Total body, subcutaneous, visceral and total fat areas and very low-density, low-density, normal density, high-density, very high-density and total muscle areas were obtained from CT images. Results: Body composition measures and overall mortality correlated with age, ECOG (Eastern Cooperative Oncology Group performance status) metastases, lactate dehydrogenase (LDH), albumin and urea levels. Although there was no relationship between body composition variables at diagnosis and overall and specific mortality, an increase in low-density muscle and a decrease in normal-density muscle during follow-up were independently correlated to overall (p <0.05) and tumor-cause mortality (p < 0.05). Conclusion: Although body composition measures obtained by CT at diagnosis did not impact survival of GEP-NET patients, a loss of good quality muscle during follow-up was associated with an increased overall and tumor-related mortality. Nutritional status should therefore be supervised by nutrition specialists and an increase in good quality muscle could improve prognosis.

Neuroendocrine Tumors: A Comprehensive Review on Nutritional Approaches

Neuroendocrine neoplasms are a heterogeneous group of neoplasms with increasing incidence, high prevalence, and survival worldwide. About 90% of cases are well differentiated forms, the so-called neuroendocrine tumors (NETs), with slow proliferation rates and prolonged survival but frequent development of liver metastases and endocrine syndromes. Both the tumor itself and systemic therapy may have an impact on patient nutrition. Malnutrition has a negative impact on outcome in patients with NETs, as well as obesity. In addition, obesity and metabolic syndrome have been shown to be risk factors for both the development and prognosis of NET. Therefore, dietary assessment based on body composition and lifestyle modifications should be an integral part of the treatment of NET patients. Nutrition plans, properly formulated by a dietician, are an integral part of the multidisciplinary treatment team for patients with NETs because they allow an improvement in quality of life, providing a tailored approach based on nutritional needs and nutritional manageable signs and/or symptoms related to pharmacological treatment. The aim of this review is to condense the latest evidence on the role of the most used dietary models, the Mediterranean diet, the ketogenic diet, and intermittent fasting, in the context of NETs, while considering the clinical and molecular mechanisms by which these dietary models act.

"Planeterranea": An attempt to broaden the beneficial effects of the Mediterranean diet worldwide

Non-communicable diseases (NCDs) lead to a dramatic burden on morbidity and mortality worldwide. Diet is a modifiable risk factor for NCDs, with Mediterranean Diet (MD) being one of the most effective dietary strategies to reduce diabetes, cardiovascular diseases, and cancer. Nevertheless, MD transferability to non-Mediterranean is challenging and requires a shared path between the scientific community and stakeholders. Therefore, the UNESCO Chair on Health Education and Sustainable Development is fostering a research project-"Planeterranea"-aiming to identify a healthy dietary pattern based on food products available in the different areas of the world with the nutritional properties of MD. This review aimed to collect information about eating habits and native crops in 5 macro-areas (North America, Latin America, Africa, Asia, and Australia). The information was used to develop specific "nutritional pyramids" based on the foods available in the macro-areas presenting the same nutritional properties and health benefits of MD.

Impact of baseline body mass index on the outcomes of patients with neuroendocrine neoplasms

OBJECTIVE

To assess the impact of baseline body mass index (BMI) on the outcomes of patients with neuroendocrine neoplasms (NENs) in a population-based setting.

METHODS

Linked provincial administrative databases (within the province of Alberta, Canada), 2004-2019, were accessed, and patients with NENs and complete information about BMI near the time of diagnosis were reviewed. The impact of BMI on overall survival was evaluated through the use of Kaplan-Meier survival estimates and multivariable Cox regression modeling.

RESULTS

A total of 1010 patients with NENs and BMI information were included. Using Kaplan-Meier survival estimates, survival outcomes were best with individuals with obesity and were worst with underweight individuals (P < 0.0001). The following factors were associated with worse overall survival, older age (HR: 1.02; 95% CI: 1.01-1.03), male sex (HR: 1.60; 95% CI: 1.32-1.93), higher Charlson comorbidity index (HR: 1.22; 95% CI: 1.13-1.31), non-small intestinal primary (HR for gastric primary versus small intestinal primary: 2.36; 95% CI: 1.44-3.85), stage 4 disease (HR: 2.67; 95% CI: 2.16-3.31), neuroendocrine carcinoma histology (HR: 1.76; 95% CI: 1.43-2.17), and underweight BMI (HR versus normal BMI: 1.74; 95% CI: 1.11-2.73). When the model was repeated using BMI as a continuous variable (rather than as a categorical variable), increasing BMI was associated with better overall survival (HR with increasing BMI: 0.97; 95% CI: 0.95-0.98).

CONCLUSIONS

Lower BMI is associated with worse overall survival among patients with NENs. This finding was demonstrable regardless of the tumor's stage or histology.

Morfo-functional nutritional status in patients with gastroenteropancreatic neuroendocrine tumors (GEPNET)

INTRODUCTION

Patients with gastroenteropancreatic neuroendocrine tumors (GEPNET) can suffer from malnutrition. This is the first descriptive study of morfo-functional evaluation in GEPNET.

OBJETIVES

To describe a morfo-functional evaluation, and to compare with reference population available, and to correlate different nutritional parameters. Moreover, to compare nutritional evaluation in our study with another same location non-neuroendocrine tumors.

MATERIALS AND METHODS

A retrospective observational study, 50 patients with GEPNET, medium age 61 years. It was collected clinico-pathological characteristics and nutritional status was assessed by anthropometric, laboratory test, bioelectrical impedance analysis, phase angle, hand grip strength, and rectus femoris ultrasound for the assessment of muscle mass. We used SPSS statistics to describe and to analyze correlations of different variables.

RESULTS

Most frequent location of tumor was pancreas and small bowel, tumor grade 1 and advance stage. In morfo-functional evaluation highlighted: a low fat mass percentage (23,5 vs 34,4%), low muscle mass percentage (36,5 vs 41,2%) and low body mass cell percentage (40,4 vs 48,8%) compared with reference population available by sex and age. Standarized phase angle by sex and age result as positive (+0,851). There was no difference in hand grip strength compared with reference population. After a review of differents studies available, phase angle and hand grip strength of non neuroendocrine tumors in same location, could suggest a minor affection of nutritional state in our GEPNET sample. A positive correlation was observed between non classic methods of nutritional evaluation such as bioelectrical impedance analysis, hand grip strength and rectus femoris ultrasound.

CONCLUSION

Patients with gastroenteropancreatic neuroendocrine tumors (GEPNET) show a moderate affection of nutritional status in comparison to general population. Morphofunctional assessment provide us a precise knowledge about nutritional status.

The associations between serum high-density lipoprotein cholesterol levels and malignant behavior in pancreatic neuroendocrine neoplasms

Background

The role of serum high-density lipoprotein cholesterol (HDL-c) in tumorigenesis are observed in several endocrine-related cancers. However, its role in pancreatic neuroendocrine neoplasms (PNENs) has not been understood. In the current study, the relationship between HDL-c levels and malignant behavior in PNENs was explored.

Methods

One hundred ninety-seven patients with histopathology confirmed PNENs were included. PNENs were divided into three grades (G1, G2 and G3) as 2017 WHO classification based on ki67 index and mitosis count. The demographic data, clinical information, tumor morphological and pathological features (organs invasion, lymph node metastasis, vascular invasion and perineural invasion), and serum tumor biomarkers were collected. The relationships between HDL-c levels and malignant behaviors in PNENs were analyzed using logistic regression analysis. Models were also developed for the identification of high grade PNENs.

Results

The levels of serum HDL-c in G2/G3 tumor were significantly lower than that in G1 tumor (P = 0.031). However, no such difference was found between G3 and G1/G2. The proportions of low HDL-c (≤ 0.9 mmol/L) were higher in high-grade PNENs (G2/G3 or G3) than those in low-grade (G1 or G1/G2) (29.0 vs 15.2%, P = 0.032; 37.0 vs 20.5%, P = 0.023). The risk of G2/G3 tumors in patients with high serum HDL-c levels was decreased (odds ratio (OR) = 0.35, 95% confidence interval (CI): 0.12–0.99). Similarly, the risk of G3 PNENs increased in patients with low HDL-c levels (OR = 2.51, 95%CI:1.12–5.60). HDL-c level was also associated with a high ki67 index (> 55%) (OR = 0.10, 95%CI: 0.02–0.51) and neuroendocrine carcinoma G3 (OR = 0.21, 95%CI: 0.06–0.80). The area under the curve (AUC) of HDL-c + tumor size + age was 0.85 (95% CI: 0.79–0.91) in identifying G2/G3 PNENs, and HDL-c (> 0.9 mmol/L) + tumor size + age had an AUC of 0.77 (95% CI: 0.70–0.84) in identifying G3 PNENs. HDL-c level was associated with lymph node metastasis (OR = 0.24, 95%CI:0.08–0.99).

Conclusion

Serum HDL-c levels were significantly associated with malignant behaviors in PNENs, in particular to tumor grade and lymph node metastasis.

Adherence to the Mediterranean Diet as a Modifiable Risk Factor for Thyroid Nodular Disease and Thyroid Cancer: Results From a Pilot Study

Iodine deficiency is the most important established nutritional risk factor for the development of thyroid nodular disease. Nevertheless, to the best of our knowledge, to date no study focused on the association between the adherence to the Mediterranean diet (MD) and thyroid nodular disease. Adherence to the MD was evaluated using the PREvención con DIetaMEDiterránea (PREDIMED) questionnaire. Physical activity, smoking habits, and anthropometric parameters were studied. PREDIMED was used to evaluate the degree of adherence to the MD. Evaluation of fine needle aspiration cytology of thyroid lesions based on 2013 Italian thyroid cytology classification system. Cytology of thyroid nodules was carried out through sonography-guided fine-needle aspiration and patients were divided into 5 categories: TIR2, TIR3a, TIR3b, TIR4, and TIR5. The study population consisted of 794 subjects (554 females, 69.8%), aged 18–65 years, with BMIs ranging from 19.4 to 55.3 kg/m². Thyroid nodular disease was present in 391 participants (49.2%), and the most frequent cytological categories was TIR2 (18.3 %), followed by a TIR4 (8.9 %). The presence of thyroid nodules was also significantly associated with the lowest adherence to the MD (OR 6.16, p < 0.001). Patients with TIR5 had the lower adherence to the MD (2.15 ± 1.12 score) compared to other TIRs (p < 0.001). The cytological category with high-risk of malignancy (TIR4/TIR5) was significantly associated with the lowest adherence to the MD (OR 137.55, p < 0.001) and PREDIMED score (OR = 0.33, p < 0.001, 95% IC = 0.26–0.41, R² = 0.462). At multiple regression analysis, PREDIMED score was the main predictor of both the presence of nodules (p < 0.001) and the cytological category with high-risk of malignancy (p < 0.001). At ROC analysis PREDIMED score ≤ 5 and ≤ 4 (p = 0.001) were the values that predicted the presence of thyroid nodular disease and cytological category with high-risk of malignancy, respectively. In conclusion, our study demonstrated that the low adherence to the MD is associated with the presence of thyroid nodular disease and in particular with those at high-risk of malignancy.

Prevalence of malnutrition and nutrition-related complications in patients with gastroenteropancreatic neuroendocrine tumours

Cross-sectional studies report that up to 25% of people with gastroenteropancreatic neuroendocrine tumours (GEP NET) are malnourished. However, the changes in nutritional status and dietary intake over time are unknown. The present study aimed to comprehensively describe the impact of a GEP NET on nutritional status and quality of life (QOL). Patients diagnosed with a GEP NET were recruited to this prospective longitudinal study on initial attendance to the NET Unit at two tertiary hospitals in Melbourne (VIC, Australia). Patient self-reported QOL measures (European Organisation for Research and Treatment Cancer QLC-C30 and QLC-GINET21) and nutritional outcomes (nutritional status, weight change, fat-free mass [FFM], dietary change, dietitian contact) were collected bi-monthly for six months. Sixty-one patients were recruited (66% male) with a mean ± SD age of 62 ± 12 years, predominantly diagnosed with small intestinal NET and Grade 1/2 disease. Commonly reported symptoms were fatigue (79%), abdominal discomfort (75%) and pain (68%). More patients were malnourished at baseline than at 6 months (29% vs. 13%). Over this 6 months, 48% lost weight, 20% lost ≥ 5% of their body weight, and 62% lost FFM with an average FFM loss of 2.8 kg (95% confidence interval = 2.0, 3.6), consistent with altered body composition. Dietary change was reported by 56% at baseline and 53% at six months, but only 21% consulted a dietitian at baseline and 18% at 6 months. Clinically significant loss of weight and FFM affected many patients with a GEP NET; however, few patients were referred to/or received a consultation with a dietitian. Valid screening practices are needed to identify weight loss and nutrition issues in GEP NET patients, and to facilitate referral to dietitian services.

Sex differences in carcinoid syndrome: A gap to be closed

The incidence of neuroendocrine neoplasms and related carcinoid syndrome (CS) has markedly increased over the last decades and women seem to be more at risk than men for developing CS. Nevertheless, very few studies have investigated sex differences in clinical presentation and outcomes of CS. However, as per other tumours, sex might be relevant in influencing tumour localization, delay in diagnosis, clinical outcomes, prognosis and overall survival in CS. The present review was aimed at evaluating sex differences in CS, as they emerge from an extensive search of the recent literature. It emerged that CS occurs more frequently in female than in male patients with NENs and women seem to have a better prognosis and a slight advantage in overall survival and response to therapy. Moreover, the disease likely impacts differently the quality of life of men and women, with different psychological and social consequences. Nevertheless, sex differences, even if partially known, are deeply underestimated in clinical practice and data from clinical trials are lacking. There is urgent need to increase our understanding of the sex-related differences of CS, in order to define tailored strategies of management of the disease, improving both the quality of life and the prognosis of affected patients.

Dietary Recommendations for Post-COVID-19 Syndrome

At the beginning of the coronavirus disease (COVID-19) pandemic, global efforts focused on containing the spread of the virus and avoiding contagion. Currently, it is evident that health professionals should deal with the overall health status of COVID-19 survivors. Indeed, novel findings have identified post-COVID-19 syndrome, which is characterized by malnutrition, loss of fat-free mass, and low-grade inflammation. In addition, the recovery might be complicated by persistent functional impairment (i.e., fatigue and muscle weakness, dysphagia, appetite loss, and taste/smell alterations) as well as psychological distress. Therefore, the appropriate evaluation of nutritional status (assessment of dietary intake, anthropometrics, and body composition) is one of the pillars in the management of these patients. On the other hand, personalized dietary recommendations represent the best strategy to ensure recovery. Therefore, this review aimed to collect available evidence on the role of nutrients and their supplementation in post-COVID-19 syndrome to provide a practical guideline to nutritionists to tailor dietary interventions for patients recovering from COVID-19 infections.

A practical nutritional guideline to manage neuroendocrine neoplasms through chronotype and sleep

Chronotype is the attitude of subjects to carry out their daily activities mainly in the morning ("lark") or in the evening ("owl"). The intermediate chronotype is located between these two categories. It has been demonstrated that chronotype can influence the incidence, course and response to treatments of tumors. In particular patients diagnosed with gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) and evening chronotype are characterized by unhealthy lifestyle, obesity, metabolic syndrome, a worsen cardiometabolic profile, a poor prognosis with a progressive disease and the development of metastasis. In addition, evening chronotype has been associated with sleep disturbances, which in turn have been related to tumor development and progression of tumors. There is a strict connection between sleep disturbances and NENs because of the hyperactivation of proangiogenic factors that caused aberrant neoangiogenesis. A nutritional tailored approach could represent a tool to align subjects with evening chronotype to physiological biological rhythms based on the properties of some macro and micronutrients of being substrate for melatonin synthesis. Thus, we aimed to provide an overview on the association of chronotype categories and sleep disturbances with NENs and to provide nutritional advices to manage subjects with NENs and these disturbances of circadian rhythm.

Vitamin D deficiency and tumor aggressiveness in gastroenteropancreatic neuroendocrine tumors

PURPOSE

Data regarding vitamin D status in patients affected by gastroenteropancreatic (GEP) neuroendocrine tumor (NET) are limited and often showing contrasting results. The aim of the study was to evaluate the incidence of vitamin D deficiency (<20 ng/mL) in GEP-NET patients and compare the 25-hydroxyvitamin D (25(OH)D) levels with clinicopathological parameters and clinical outcome.

METHODS

A retrospective cross-sectional study including 75 low grade (G1-G2) GEP-NETs and 123 healthy controls matched for age, sex, and body mass index, was performed.

RESULTS

GEP-NET patients had significantly lower 25(OH)D levels compared to controls (17.9 ± 7.8 vs 24.2 ± 7.7 ng/mL, p < 0.0001). Ileal NETs were associated to lower 25(OH)D levels compared to other primary tumor sites (p = 0.049) and small bowel resection posed a significant increased risk of severe vitamin D deficiency (OR = 2.81, 95% CI = 1.25-3.37, p = 0.018). No correlation with somatostatin analogs treatment was found. 25(OH)D levels were significantly lower in G2 compared to G1 GEP-NETs (15.6 ± 7.8 vs 19.9 ± 7.4 ng/mL, p = 0.016) and in patients with progressive disease (12.6 ± 5.7 ng/mL) compared to those with stable disease (mean 21.5 ± 8.2 ng/mL, p = 0.001) or tumor free after surgery (19.6 ± 7.3 ng/mL, p = 0.002). Patients with vitamin D deficiency and insufficiency had shorter progression-free survival compared to those with sufficiency (p = 0.014), whereas no correlation was found with disease-specific survival.

CONCLUSIONS

Vitamin D deficiency is highly prevalent among GEP-NETs and could be associated with high tumor grade and disease progression. Therefore, the monitoring of 25(OH)D levels is relevant in these patients and vitamin D supplementation should be considered in the management of GEP-NET patients with vitamin D deficiency or insufficiency.

Mediterranean Diet: What Are the Consequences for Menopause?

Menopause is a natural event occurring in a woman's life that is often accompanied by symptoms that might affect the quality of life. Diet has been shown to influence menopausal-related symptoms. Therefore, the present study aimed to investigate whether the adherence to the Mediterranean Diet (MD) might influence menopausal symptoms in women with obesity. This cross-sectional study involved postmenopausal women with obesity. Anthropometric and clinical parameters, and lifestyle habits were evaluated. All participants underwent interview questionnaires to assess: the adherence to the MD (PREDI PREvencion con DIetaMEDiterranea, PREDIMED), sleep quality (Pittsburgh Sleep Quality Index, PSQI), and severity of menopausal symptoms (Menopausal Rating Scale, MRS). One hundred postmenopausal women were enrolled (age 57.1 ± 7.3 years, BMI 35.0 ± 5.5 kg/m²). The mean PREDIMED score was 7.82 ± 1.66 showing moderate adherence to MD. Women in the marked MRS class had a significantly lower PREDIMED score than the none-to-moderate MRS class (p=0.036). The intake of legumes was associated with a lower MRS class (r= -0.201, p=0.045). In addition, the intake of extra-virgin olive oil inversely correlated with psychological symptoms (r= -0.230 p=0.021). Finally, 79% of participants were poor sleepers (mean PSQI score was 8.68 ± 3.6) and women in the severe MRS class had a worse sleep quality compared to other MRS classes. Post-menopausal women with marked menopausal symptoms had low adherence to MD. Legume consumption was associated with lower menopausal symptoms severity while extra virgin olive oil consumption was associated with lower psychological symptoms.

Sarcopenia and Ghrelin System in the Clinical Outcome and Prognosis of Gastroenteropancreatic Neuroendocrine Neoplasms

Simple Summary

Malnutrition and sarcopenia affect clinical outcomes in cancer patients. Nutritional evaluation in patients with neuroendocrine neoplasms (NENs) is not routinely performed. Currently, the evaluation of sarcopenia using CT scans is the gold standard in cancer patients, additionally, anthropometric, biochemical and molecular analysis of patients with gastroenteropancreatic NENs at diagnosis was perfomed. The expression levels of key ghrelin system components were assessed in 63 tumor samples. Results: Nutritional parameters were similar in GEP-NEN tumors of different origin. Relapsed disease was associated with decreased BMI. Patients who presented with weight loss at diagnosis had significantly lower overall survival (108 (25–302) vs. 263 (79–136) months). Ghrelin O-acyltransferase (GOAT) enzyme expression was higher in these patients. The prevalence of sarcopenia using CT images reached 87.2%. Mortality was observed only in patients with sarcopenia. Muscle evaluation was correlated with biochemical parameters but not with the expression of ghrelin system components. Conclusion: Survival is related to the nutritional status of patients with GEP-NENs and also to the molecular expression of some relevant ghrelin system components. Routine nutritional evaluation should be performed in these patients, in order to prescribe appropriate nutritional support, when necessary, for increasing quality of life and improving clinical outcomes.

Abstract

Background: Malnutrition and sarcopenia affect clinical outcomes and treatment response in cancer patients. Patients with neuroendocrine neoplasms (NENs) may present with additional symptoms related to tumor localization in the gastrointestinal tract and hormone secretion, increasing the risk and effects of sarcopenia. Aim: To explore the presence of malnutrition and sarcopenia in gastroenteropancreatic (GEP)-NEN patients, their relation to tumor characteristics, patient outcomes, survival and the molecular expression of ghrelin system components in the tumor. Patients and methods: One-hundred-and-four patients were included. Anthropometric, biochemical and CT-scans at diagnosis were evaluated. The expression levels of key ghrelin system components were assessed in 63 tumor samples. Results: Nutritional parameters were similar in GEP-NEN tumors of different origin. Relapsed disease was associated with decreased BMI. Patients who presented with weight loss at diagnosis had significantly lower overall survival (108 (25–302) vs. 263 (79–136) months). Ghrelin O-acyltransferase (GOAT) enzyme expression was higher in these patients. The prevalence of sarcopenia using CT images reached 87.2%. Mortality was observed only in patients with sarcopenia. Muscle evaluation was correlated with biochemical parameters but not with the expression of ghrelin system components. Conclusion: Survival is related to the nutritional status of patients with GEP-NENs and also to the molecular expression of some relevant ghrelin system components. Routine nutritional evaluation should be performed in these patients, in order to prescribe appropriate nutritional support, when necessary, for increasing quality of life and improving clinical outcomes.

Cardio-Metabolic Indices and Metabolic Syndrome as Predictors of Clinical Severity of Gastroenteropancreatic Neuroendocrine Tumors

BACKGROUND

Obesity, mainly visceral obesity, and metabolic syndrome (MetS) are major risk factors for the development of type 2 diabetes, cardiovascular diseases, and cancer. Data analyzing the association of obesity and MetS with gastroenteropancreatic neuroendocrine neoplasms (GEP-NEN) are lacking. Fatty liver index (FLI) is a non-invasive tool for identifying individuals with non-alcoholic fatty liver disease (NAFLD). Visceral adiposity index (VAI) has been suggested as a gender-specific indicator of adipose dysfunction. Both indexes have been proposed as early predictors of MetS. This study aimed to investigate the association of FLI VAI as early predictors of MetS with gastroenteropancreatic neuroendocrine tumors (GEP-NETs).

METHODS

A cross-sectional, case-control, observational study was carried out at the ENETS Centers of Excellence Multidisciplinary Group for Neuroendocrine Tumors, University "Federico II". VAI and FLI were calculated.

RESULTS

We enrolled 109 patients with histologically confirmed G1/G2 GEP-NET (53 M; 57.06 ± 15.96 years), as well as 109 healthy subjects, age, sex- and body mass index-matched. Forty-four GEP-NET patients were G2, of which 21 were with progressive disease, and 27 patients had metastases. GEP-NET patients had a higher value of VAI (p < 0.001) and FLI (p = 0.049) and higher MetS presence (p < 0.001) compared with controls. VAI and FLI values and MetS presence were higher in G2 than in G1 patients (p < 0.001), in patients with progressive disease, and in metastatic vs non-metastatic patients (p < 0.001). In addition, higher values of VAI and FLI and higher MetS presence were significantly correlated with the worst clinical severity of NENs. The cut-off values for the FLI and MetS to predict high grading of GEP-NETs and the presence of metastasis were also provided.

CONCLUSIONS

This is the first study investigating an association between VAI and FLI as early predictors of MetS and GEP-NET. Our findings report that the worsening of clinicopathological characteristics in GEP-NET is associated with higher presence of MetS, NAFLD, evaluated by FLI, and visceral adiposity dysfunction, evaluated by VAI. Addressing the clinical evaluation of MetS presence, NAFLD, and visceral adiposity dysfunction might be of crucial relevance to establish targeted preventive and treatment interventions of NEN-related metabolic comorbidities.

Could ketogenic diet "starve" cancer? Emerging evidence

Cancer cells (CCs) predominantly use aerobic glycolysis (Warburg effect) for their metabolism. This important characteristic of CCs represents a potential metabolic pathway to be targeted in the context of tumor treatment. Being this mechanism related to nutrient oxidation, dietary manipulation has been hypothesized as an important strategy during tumor treatment. Ketogenic diet (KD) is a dietary pattern characterized by high fat intake, moderate-to-low protein consumption, and very-low-carbohydrate intake (<50 g), which in cancer setting may target CCs metabolism, potentially influencing both tumor treatment and prognosis. Several mechanisms, far beyond the originally proposed inhibition of glucose/insulin signaling, can underpin the effectiveness of KD in cancer management, ranging from oxidative stress, mitochondrial metabolism, and inflammation. The role of a qualified Nutritionist is essential to reduce and manage the short and long-term complications of this dietary therapy, which must be personalized to the individual patient for the planning of tailored KD protocol in cancer patients. In the present review, we summarize the proposed antitumor mechanisms of KD, the application of KD in cancer patients with obesity and cachexia, and the preclinical and clinical evidence on KD therapy in cancer.

Role of Diet in the Management of Carcinoid Syndrome: Clinical Recommendations for Nutrition in Patients with Neuroendocrine Tumors

Nutrition and metabolism are altered in patients with gastroenteropancreatic neuroendocrine tumors, which is related to excessive production of gastrointestinal hormones, peptides, and amines that can cause maldigestion, diarrhea, steatorrhea, and altered gastrointestinal motility. Patients with carcinoid syndrome are at risk of malnutrition due to tryptophan depletion, reduced intake of food, and loss of appetite because of diarrhea and/or flushing. To date, there is limited information on the nutritional issues faced by patients with neuroendocrine tumors, and on what specific recommendations should be made to patients concerning nutrition at various stages of the disease process. Dietary planning should therefore be an integral part of multidisciplinary management for patients with neuroendocrine tumors. Herein, we review current guidance for nutrition in patients with neuroendocrine tumors, focusing on intake of amines and foods to avoid, as well as concurrent medications. We also propose a new and practical food pyramid based on the principles of Mediterranean diet 4.0 that can be easily adapted according to the unmet needs of patients with neuroendocrine tumors at all stages of disease. The overarching goal of the present review is to create greater awareness of nutritional care and considerations that should be given to patients with neuroendocrine tumors.

Ketogenic diet: a tool for the management of neuroendocrine neoplasms?

Neuroendocrine neoplasms (NENs) are a heterogeneous group of neoplasms, whose incidence has rapidly increased in the last years. Nutrition plays an important role in their management; indeed, malnutrition negatively impacts on rates of complications, hospitalization, hospital stay, costs and mortality. Furthermore, it has been reported that a poor nutritional status could influence the outcome of patients with pancreatic NENs. Moreover, obesity, predisposing to insulin resistance and compensatory hyperinsulinemia, could stimulate the growth of these neoplasms. Ketogenic diet (KD), a high-fat, low-carbohydrate diet with adequate amounts of protein, has been reported to be a promising approach for the management of several types of cancer, mostly gynecological and neurological ones. Indeed, it appears to sensitize most cancers to standard treatment by exploiting the reprogramed metabolism of cancer cells and thus resulting in a promising candidate as an adjuvant cancer therapy. Thus, the aim of this review is to provide an overview on the importance of nutrition in cancer management and in particular in NENs' setting. Furthermore, we reported the current evidence on the efficacy of KD in the management of cancer and based on molecular mechanisms; we also hypothesize the potential use of this nutritional pattern in the management of NENs.

Epidemiology of pancreatic neuroendocrine neoplasms: a gender perspective

PURPOSE

Pancreatic neuroendocrine neoplasms (PNENs) are a group of clinically rare and heterogeneous tumors of the pancreas. Currently there are no studies investigating the gender difference in PNEN susceptibility. Thus, the purpose of this study was aimed at examining how gender shapes risk factors, clinicopathological features, and comorbidities in PNENs.

METHODS

The study design consisted of an Italian multicenter, retrospective study. The study included all consecutive patients with PNENs followed at the participating centers. Two hundred and twenty-nine patients (105 males,124 females, age 54 ± 0.98 years) with PNENs were enrolled at the participating centers. The clinicopathological features (age, gender, BMI, histology, tumor size, tumor grade, distant metastasis, hormonal function, and diagnostic circumstances), comorbidities (cardiovascular diseases (CVD), pancreatitis, type 2 diabetes (T2DM), and potential risk factors (smoking and drinking) were included in the analysis.

RESULTS

Females were slightly prevalent (54.15%). PNENs were diagnosed at younger age in females compared to males (p = 0.04). The prevalence of CVD was significantly higher in males than in females (p = 0.006). In the female group, the presence of T2DM was significantly associated with higher tumor grade (p = 0.04) and metastatic disease (p = 0.02). The proportion of smokers and alcohol drinkers was significantly higher in the male group (p < 0.001). No significant gender differences were detected regarding the other parameters included in the analysis.

CONCLUSIONS

This study has identified gender differences of PNENs in terms of age at diagnosis, associated comorbidities, and potential risk factors. A gender-tailored approach could become a potential strategy to better understand the natural history of PNENs and improve the effectiveness of PNENs clinical management.

Nutrition and immune system: from the Mediterranean diet to dietary supplementary through the microbiota

The interaction between nutrition and the immune system is very complex. In particular, at every stage of the immune response, specific micronutrients, including vitamins and minerals play a key role and often synergistic, and the deficiency of only one essential nutrient may impair immunity. An individual's overall nutrition status and pattern of dietary intake (comprised of nutrients and non-nutritive bioactive compounds and food) and any supplementation with nutraceuticals including vitamins and minerals, can influence positively or negatively the function of the immune system. This influence can occur at various levels from the innate immune system and adaptive immune system to the microbiome. Although there are conflicting evidence, the current results point out that dietary supplementation with some nutrients such as vitamin D and zinc may modulate immune function. An update on the complex relationship between nutrition, diet, and the immune system through gut microbiota is the aim of this current review. Indeed, we will provide the overview of the link among immune function, nutrition and gut microbiota, paying particular attention at the effect of the Mediterranean diet on the immune system, and finally we will speculate the possible role of the main one functional supplements on immune function.

An Update on Gastroenteropancreatic Neuroendocrine Neoplasms: From Mysteries to Paradigm Shifts

Although neuroendocrine neoplasms (NEN) were once thought to be rare and mostly "benign" diseases, they are now being redefined in light of recently discovered molecular information. NENs constitute a spectrum of variably differentiated neoplasms, ranging from well-differentiated tumors with a protracted course over many years to very aggressive neuroendocrine carcinomas. Although the majority of NEN are non-functional lesions, some of these tumors, do produce a hormonal hypersecretion syndrome. Their reappraisal has led scientist to unveil previously unknown oncogenic pathways and connections that resulted in a new category in the International Classification of Diseases (ICD-11) and a revised version of the World Health Organization Classification (WHO 2018). Complex diseases like NEN require a multidisciplinary approach that includes the perspectives of endocrinologists, medical and surgical oncologists, radiation oncologists, imaging specialists and pathologists. There are currently virtually thousands of ongoing trials evaluating the efficacy and safety of several molecular targeted therapies. The purpose of this review was to critically evaluate recent information regarding the pathogenesis, diagnosis and treatment of NEN.

New-generation anti-obesity drugs: naltrexone/bupropion and liraglutide. An update for endocrinologists and nutritionists

The prevalence of obesity increases worldwide and has a significant economic impact on health care systems. A comprehensive program of lifestyle modification, including diet, exercise, and behavior therapy is considered the first option for achieving the significant weight loss. However, the intrinsic difficulties associated with maintenance of lifestyle changes contribute to the unsatisfactory long-term outcomes reported and weight regain in the obesity management. In this context, pharmacological approaches are useful to maximize non-pharmacological interventions in the long-term management of obesity. As add-on to lifestyle modification, pharmacological interventions are useful to facilitate clinically weight loss. In the past, anti-obesity drugs were limited. To date, the landscape has changed and naltrexone/bupropion and liraglutide have been recently added as new-generation anti-obesity drugs on obesity treatment and could represent important tools to manage of obesity. Liraglutide is a glucagon-like peptide 1 (GLP-1) receptor agonist that shares 97% homology to native GLP-1 with effects on the limbic system. The treatment with liraglutide 3.0 mg, in combination with a hypocaloric diet and increased physical activity, provides a clinically meaningful weight loss. The combination of naltrexone 32 mg and bupropion 360 mg acts on the mesolimbic reward pathway and the hypothalamic hunger system, two areas of the central nervous system. The combination of naltrexone/bupropion, an adjunct to a hypocaloric diet and increased physical activity, is approved for chronic weight management in adults with obesity or overweight and ≥1 weight-related comorbidity. In the present review, we have focused on the current evidence on two new-generation anti-obesity drugs, naltrexone/bupropion and liraglutide 3.0 mg addressing the main studies that investigated these two new drugs for obesity treatment. Furthermore, evidence on semaglutide, currently in the pipeline for potential future therapeutic use for weight loss, are reported.

Assessment and State of Nutrition of Patients with Gastroenteropancreatic Neuroendocrine Neoplasms

Introduction: In recent decades, the number of gastro-entero-pancreatic neuroendocrine neoplasms (GEP-NENs) cases, associated with coexisting metabolic disorders, has been continuously increasing. Patients with progressing neoplastic disease are at a risk of malnutrition. To improve the quality of life of neuroendocrine neoplasms (NEN) patients, the therapeutic approach should be supported by a well-balanced diet. The aim of the study was to analyze the nutritional errors and deficits in a group of GEP-NET patients. Materials and methods: The study group included 26 GEP-NET patients; 13 men and 13 women. The mean age of women was 68.77 ± 8.0, and the mean age of men was 64.69 ± 8.1. Three interviews on consumption in the last 24 h were performed, in order to evaluate the quality and quantity of nutrition. The data was incorporated into a dietetics software, which allows one to calculate the number of over 58 micronutrients and macronutrients with the participation of 52 menus. Subsequently, the mean values were compared with the current nutritional standards. Results: An energy deficit was observed in the group of women—76.9%, and men—100%, as well as high fat consumption in 23.1% in both groups. The proportions of SFA/MUFA/PUFA were very negative, whereas the consumption of saccharose was too high. Vitamin D deficiency was observed in 100% of men and women. Moreover, both men and women experienced the deficiency of vitamin E, folates and niacin. The consumption of sodium and phosphorus was twice as high as recommended, and an insufficient supply of calcium was observed in 80% of women and 90% of men. The insufficient consumption of magnesium, iodine and potassium in a significant part of the studied group was observed. All participants consumed too much cholesterol and insufficient amounts of fiber. The healthy diet indicator (HDI) and diet quality index (DQI) scores were 3.1 ± 1.8 (HDI) and 3.7 ± 1.6 (DQI) for women, and 7.2 ± 2.6 (HDI) and 8.5 ± 2.4 (DQI) for men. Conclusions: When analyzing the nutrition of GEP-NET patients, we highlight that they do not have a proper diet, despite the fact that they changed the way they eat. Dietetics support and the development of official nutritional standards seem to be a necessary element in the therapy of GEP-NET patients.

The Neuroendocrine Neoplasms of the Digestive Tract: Diagnosis, Treatment and Nutrition

Nuroendocrine neoplasms (NENs) are a group of rare neoplasms originating from dispersed neuroendocrine cells, mainly of the digestive and respiratory tract, showing characteristic histology and immunoprofile contributing to classification of NENs. Some NENs have the ability to produce biogenic amines and peptide hormones, which may be associated with clinical syndromes like, e.g., the carcinoid syndrome caused by unmetabolized overproduced serotonin, hypoglycemic syndrome in case of insulinoma, or Zollinger-Ellison syndrome accompanying gastrinoma. Diagnostics for these include ultrasound with endoscopic ultrasound (EUS), computed tomography (CT), magnetic resonance imaging (MRI), and positron-emission tomography/computed tomography (PET/CT). Different nuclear medicine procedures can also be used, like somatostatin analogues scintigraphy (SRS) and 68Ga-Dota-Peptide PET/CT, as well as biochemical methods to determine the level of general neuroendocrine markers, such as chromogranin A (CgA), 5-hydroxyindolacetic acid (5-HIAA), synaptopfysin and cell type-specific peptide hormones, and neurotransmitters like gastrin, insulin, serotonin, and histamine. NENs influence the whole organism by modulating metabolism. The treatment options for neuroendocrine neoplasms include surgery, somatostatin analogue therapy, radionuclide therapy, chemotherapy, molecular targeted therapies, alpha-interferon therapy, and inhibitors of serotonin production. In the case of hypersensitivity to biogenic amines, a diet that limits the main sources of amines should be used. The symptoms are usually connected with histamine, tyramine and putrescine. Exogenic sources of histamine are products that take a long time to mature and ferment. Patients with a genetic insufficiency of the diamine oxidase enzyme (DAO), and those that take medicine belonging to the group of monoamine oxidases (MAO), are particularly susceptible to the negative effects of amines. Diet plays an important role in the initiation, promotion, and progression of cancers. As a result of the illness, the consumption of some nutrients can be reduced, leading to nutritional deficiencies and resulting in malnutrition. Changes in metabolism may lead to cachexia in some patients suffering from NENs. The aim of this narrative review was to advance the knowledge in this area, and to determine possibilities related to dietary support. The authors also paid attention to role of biogenic amines in the treatment of patients with NENs. We can use this information to better understand nutritional issues faced by patients with gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs), and to help inform the development of screening tools and clinical practice guidelines.

Bone Metabolism and Vitamin D Implication in Gastroenteropancreatic Neuroendocrine Tumors

Patients affected by gastroenteropancreatic–neuroendocrine tumors (GEP–NETs) have an increased risk of developing osteopenia and osteoporosis, as several factors impact on bone metabolism in these patients. In fact, besides the direct effect of bone metastasis, bone health can be affected by hormone hypersecretion (including serotonin, cortisol, and parathyroid hormone-related protein), specific microRNAs, nutritional status (which in turn could be affected by medical and surgical treatments), and vitamin D deficiency. In patients with multiple endocrine neoplasia type 1 (MEN1), a hereditary syndrome associated with NET occurrence, bone damage may carry other consequences. Osteoporosis may negatively impact on the quality of life of these patients and can increment the cost of medical care since these patients usually live with their disease for a long time. However, recommendations suggesting screening to assess bone health in GEP–NET patients are missing. The aim of this review is to critically analyze evidence on the mechanisms that could have a potential impact on bone health in patients affected by GEP–NET, focusing on vitamin D and its role in GEP–NET, as well as on factors associated with MEN1 that could have an impact on bone homeostasis.

Nutritional status and follicular-derived thyroid cancer: An update

The incidence of differentiated thyroid cancer has been increasing in the last decades all over the world. Such a steady growth cannot be entirely attributable to more intensive thyroid nodule screening and more sensitive diagnostic procedures. Several environmental factors have changed with sufficient rapidity in the same time frame and may represent credible candidates for this increase. They include modified iodine intake, lifestyle-associated risk factors, exposure to various toxic compounds, pollutants and xenobiotics, nutritional deficiencies, eating habits and comorbidities. Foremost, nutritional patterns have gained high interest as possible promoters and modifiable risk factors for thyroid cancer in recent years. The aim of this narrative review is to focus on the relationship between thyroid cancer and nutritional factors, dietary habits and obesity. Low iodine intake has been associated to increased risk of thyroid cancer, favoring the development of more aggressive histotypes. Moreover, correction of iodine deficiency can shift thyroid cancer subtypes toward less aggressive forms, without affecting the overall risk for cancer. Actually, evidence regarding the association between selenium and vitamin D deficiency and thyroid cancer is very limited, despite their well-known anti-cancer potentials, and the clinical usefulness of their supplementation is still uncertain in this setting. Albeit the relationship between single foods and thyroid cancer is difficult to examine, fish and iodine-rich foods, vegetables, and fruits might exert protective effects on thyroid cancer risk. Conversely, no clear association has been found for other foods to date. Lastly, a clear association between obesity and the risk of thyroid cancer, with more aggressive behavior, seems to emerge from most studies, likely involving variations in thyroid function and chronic inflammation mediated by cytokines, insulin, leptin and adiponectins. Although no definite association between dietary factors and thyroid cancer has been firmly established so far, some nutritional patterns, together with excessive weight, seem to play a relevant role in thyroid cancer carcinogenesis as well as in its severity and aggressiveness. These effects may play an additive role to the well-established one exerted by environmental carcinogens, such as pollutants and radiation exposure.

Nutritional Complications and the Management of Patients with Gastroenteropancreatic Neuroendocrine Tumors

Neuroendocrine tumors (NETs) have increased in incidence and prevalence over the past 2 decades and affect approximately 170,000 people in the United States alone. Gastroenteropancreatic (GEP) NETs (GEP NET) are a heterogeneous group of rare tumors that have distinct effects on the body due to their tumor location and potential to secrete hormones and peptides. Clinical practice guidelines and consensus guidelines for GEP NETs with regard to best practice for diagnosis, treatment, and medical management are available, but the supportive care needs and optimal nutritional management of patients affected by these unique tumors remain under-researched: evidence to guide clinical practice is lacking. The pathophysiology of the disease and its treatment can cause various symptoms that can have significant effects on vitamin synthesis and absorption, dietary habits, weight change, and appetite. Deficiency of fat-soluble vitamins and niacin exists amongst patients with GEP NET, particularly those on treatment with somatostatin analogs and with serotonin-secreting tumors, respectively. Malnutrition and dietary modification amongst patients with GEP NET is more prevalent than initially thought: up to 25% of inpatients with GEP NET are malnourished. Food intolerance is also reported in up to 40-90% of these patients, though its misdiagnosis is common. This review summarizes the evidence regarding the impact of GEP NET and its treatment on nutritional factors in these patients with emphasis on malnutrition, vitamin deficiencies, dietary intake, and quality of life. Recommendations for clinical practice and research approaches to address these nutritional issues are discussed.

Carcinoid Syndrome: Updates and Review of Current Therapy

OPINION STATEMENT

Carcinoid syndrome (CS) is a complex disorder caused by functional neuroendocrine tumors (NETs). This debilitating disease is characterized by hyper-secretion of biologically active substances eliciting major hormonal symptoms burden and fibrotic changes that are often challenging for management. There have been a number of insights that have substantially advanced treatments since the introduction of somatostatin analogs (SSAs). Second-line treatments are needed in a substantial proportion of patients with advanced disease that have uncontrolled hormone secretion on the highest labeled doses of SSAs. International guidelines suggest several available options including dose escalation of SSAs, interferon alpha, everolimus, radionuclide therapy, liver-directed therapies, and the novel tryptophan hydroxylase 1 inhibitor, telotristat ethyl. The clear preference of one second-line therapy over the other is not stated since their relative and long-term efficacy are largely unknown, and standardized approach of hormonal response assessment is lacking in the literature. In the clinical setting, the treatment of CS is guided in conjunction with patients' performance status, tumor origin, grade, stage, and growth rate, with regard to both anti-hormonal, as well as anti-proliferative effect. There is an unmet need for further well-designed randomized placebo-controlled and head-to-head studies that systematically assess CS symptom control and biochemical response following a specific intervention.

Impact of Nutritional Status on Gastroenteropancreatic Neuroendocrine Tumors (GEP-NET) Aggressiveness

Neuroendocrine tumors (NETs) are rare neoplasms mostly originating from the gastroenteropancreatic tract (GEP-NETs). Data regarding nutritional status in GEP-NET patients are limited. The aim of the study was to investigate the nutritional status and adherence to the Mediterranean Diet (MD) in GEP-NET patients and to correlate them with tumor aggressiveness. A cross-sectional case-control observational study was conducted enrolling 83 patients with well-differentiated G1/G2 GEP-NETs after resection, as well as 83 healthy subjects, age, sex and body mass index-matched. Nutritional status was assessed by evaluating with Bioelectrical Impedance analysis and its phase angle (PhA), adherence to the MD according to PREDIMED score, dietary assessment, anthropometric parameters, and clinico-pathological characteristics. GEP-NET patients consumed less frequently vegetables, fruits, wine, fish/seafood, nuts, and more frequently red/processed meats, butter, cream, margarine, and soda drinks than controls. Patients with more aggressive disease presented a lower adherence to MD according to PREDIMED categories in comparison to G1, localized and free/stable disease status. A smaller PhA value and a lower PREDIMED score were significantly correlated with G2 tumor, metastases, and progressive disease. To the best of our knowledge, this is the first study reporting an association between nutritional status and tumor aggressiveness in a selected group of GEP-NETs. Moreover, higher intakes of food of MD, may represent a potential tool for prevention of tumor aggressiveness. Thus, a skilled nutritionist should be an integral part of the multidisciplinary management of GEP-NET patients.