Characteristics of 252 patients with bronchopulmonary neuroendocrine tumours treated at the Copenhagen NET Centre of Excellence

Mutational analysis of pulmonary large cell neuroendocrine carcinoma: APC gene mutations identify a good prognostic factor

Pulmonary large cell neuroendocrine carcinoma (LCNEC) is a highly aggressive neoplasm with biological heterogeneity. Mutations in multiple genes have been identified in LCNEC. However, associations between gene alterations, histopathological characteristics, and prognosis remain ambiguous. Here, we investigated the clinicopathologic, immunohistochemical, and genomic characteristics of 19 patients with LCNEC and 9 patients with atypical carcinoid (AC). We revealed high mutation frequencies of TP53 (89.5 %), RB1 (42.1 %), APC (31.6 %), and MCL1 (31.6 %) in LCNEC, while genetic alterations were rarely found in AC. APC alterations mainly occurred to the exon 16 and were only identified in LCNEC with wild-type RB1. The 19 LCNEC were further subgrouped into APC wild-type (LCNEC-APCMT, 6/19) and APC-mutated (LCNEC-APCWT, 13/19) subgroups. In comparison with LCNEC-APCWT, LCNEC-APCMT displayed lower TMB (median: 12.64 vs 4.20, P = 0.045), and relatively mild cytologic atypia. In addition, LCNEC-APCMT distinguished itself from AC and LCNEC-APCWT by obviously downregulated expression of neuroendocrine markers (CD56 and Syn, P < 0.01) and significantly altered expression of genes downstream of APC (β-catenin migrating into the cytoplasm and nucleus, P < 0.001; c-Myc upregulating, P = 0.005). The OS of LCNEC-APCMT was numerically intermediate between AC and LCNEC-APCWT. We first proposed that APC alterations were common in LCNEC with wild-type RB1 and that LCNEC-APCMT was associated with lower TMB and better OS in comparison with LCNEC-APCWT.

Prognostic thresholds of fluorine-18 fluorodeoxyglucose-positron emission tomography mean and maximum standardized uptake values for survival and nodal involvement in lung neuroendocrine neoplasms

OBJECTIVES

The mean standardized uptake value (SUVmean) and maximum standardized uptake value (SUVmax) on fluorine-18 fluorodeoxyglucose-positron emission tomography are prognostic biomarkers for survival and nodal involvement in non-small-cell lung cancer but their prognostic value in lung neuroendocrine neoplasms (NENs) remains unexplored. In this study, we aimed to examine whether they are also prognostic biomarkers for survival and nodal involvement in lung NENs.

METHODS

We retrospectively studied patients with typical carcinoid, atypical carcinoid or large cell neuroendocrine carcinoma who had been radically resected at our institution between 2008 and 2020. We measured SUVmean and SUVmax on all primary tumours and lymph nodes that were clinically and/or pathologically involved. We dichotomized the patients into groups of high or low SUVmean and SUVmax of the primary tumour using time-dependent receiver operating characteristic curves and compared their overall survival using Kaplan-Meier curves and Cox models. Lastly, we predicted the patients' pathological nodal status with SUVmean and SUVmax of the lymph nodes using binomial logistic models.

RESULTS

The study included 245 patients. Patients died earlier if their SUVmean of the primary tumour exceeded 3.9 [hazard ratio 1.97, 95% confidence interval (CI) 1.27-3.04, P = 0.002] or SUVmax exceeded 5.3 (hazard ratio 1.85, 95% CI 1.20-2.87, P = 0.006). Likewise, patients had a higher risk of pathological nodal involvement if their SUVmean of the lymph nodes exceeded 3.3 (odds ratio 10.00, 95% CI 2.59-51.01, P = 0.002) or SUVmax exceeded 4.2 (odds ratio 4.00, 95% CI 1.20-14.65, P = 0.028).

CONCLUSIONS

The fluorine-18 fluorodeoxyglucose-positron emission tomography SUVmean and SUVmax are strong prognostic biomarkers for survival and nodal involvement in lung NENs and could be important guides for making treatment decisions.

Prognostic Thresholds of Mitotic Count and Ki-67 Labeling Index for Recurrence and Survival in Lung Atypical Carcinoids

Atypical carcinoid (AC) is a rare neuroendocrine neoplasm of the lung, which exhibits a varying malignant potential. In this study, we aimed to identify the prognostic thresholds of the mitotic count and Ki-67 labeling index for recurrence and survival in AC. We retrospectively reviewed 78 patients who had been radically resected for AC and calculated said thresholds using time-dependent receiver operating characteristic curves and the Youden index. We then dichotomized the patients into groups of above or below these thresholds and estimated the cumulative incidences of the groups using the Aalen-Johansen estimator. We compared the groups using univariable and multivariable Fine-Gray subdistribution hazard models. Our findings show that more patients recurred and died from this disease if their mitotic count exceeded three and four mitoses per 2 mm2, respectively, or if their Ki-67 labeling index exceeded 14% and 11%, respectively. Both thresholds independently predicted survival (p < 0.001 and p = 0.015, respectively). These thresholds may serve as a valuable tool for clinicians and researchers in making treatment plans and predicting outcomes for patients with AC.

Use and perceived utility of [18 F]FDG PET/CT in neuroendocrine neoplasms: A consensus report from the European Neuroendocrine Tumor Society (ENETS) Advisory Board Meeting 2022

Somatostatin receptor (SST) PET/CT is the gold standard for well-differentiated neuroendocrine tumours (NET) imaging. Higher grades of neuroendocrine neoplasms (NEN) show preferential [18F]FDG (FDG) uptake, and even low-grade NET may de-differentiate over time. FDG PET/CT's prognostic role is widely accepted; however, its impact on clinical decision-making remains controversial and its use varies widely. A questionnaire-based survey on FDG PET/CT use and perceived decision-making utility in NEN was submitted to the ENETS Advisory Board Meeting attendees (November 2022, response rate = 70%). In 3/15 statements, agreement was higher than 75%: (i) FDG was considered useful in NET, irrespective of grade, in case of mis-matched lesions (detectable on diagnostic CT but negative/faintly positive on SST PET/CT), especially if PRRT is contemplated (80%); (ii) in NET G3 if curative surgery is considered (82%); and (iii) in NEC prior to surgery with curative intent (98%). FDG use in NET G3, even in the presence of matched lesions, as a baseline for response assessment was favoured by 74%. Four statements obtained more than 60% consensus: (i) FDG use in NET G3 if locoregional therapy is considered (65%); (ii) in neuroendocrine carcinoma before initiating active therapy as a baseline for response assessment (61%); (iii) biopsy to re-assess tumour grade prior to a change in therapeutic management (68%) upon detection of FDG-positivity on the background of a prior G1-2 NET; (iv) 67% were in favour to reconsider PRRT to treat residual SST-positive lesions after achieving complete remission on FDG of the SST-negative disease component. Multidisciplinary opinion broadly supports the use of FDG PET/CT for characterisation of disease biology and to guide treatment selection across a range of indications, despite the lack of full consensus in many situations. This may reflect existing clinical access due to lack of reimbursement or experience with this investigation, which should be addressed by further research.

Clinic and genetic similarity assessments of atypical carcinoid, neuroendocrine neoplasm with atypical carcinoid morphology and elevated mitotic count and large cell neuroendocrine carcinoma

Background

Pulmonary neuroendocrine neoplasms can be divided into typical carcinoid, atypical carcinoid, large cell neuroendocrine carcinoma, and small cell (lung) carcinoma. According to the World Health Organization, these four neoplasms have different characteristics and morphological traits, mitotic counts, and necrotic status. Importantly, “a grey-zone” neoplasm with an atypical carcinoid-like morphology, where the mitotic rate exceeds the criterion of 10 mitoses per 2 mm², have still not been well classified. In clinical practice, the most controversial area is the limit of 11 mitoses to distinguish between atypical carcinoids and large cell neuroendocrine carcinomas.

Methods

Basic and clinical information was obtained from patient medical records. A series of grey-zone patients (n = 8) were selected for exploring their clinicopathological features. In addition, patients with atypical carcinoids (n = 9) and classical large cell neuroendocrine carcinomas (n = 14) were also included to compare their similarity to these neoplasms with respect to tumour morphology and immunohistochemical staining.

Results

We found that these grey-zone tumour sizes varied and affected mainly middle-aged and older men who smoked. Furthermore, similar gene mutations were found in the grey-zone neoplasms and large cell neuroendocrine carcinomas, for the mutated genes of these two are mainly involved in PI3K-Akt signal pathways and Pathways in cancer, including a biallelic alteration of TP53/RB1 and KEAP1.

Conclusions

Our findings indicate that neuroendocrine neoplasm with atypical carcinoid morphology and elevated mitotic counts is more similar to large cell neuroendocrine carcinoma than atypical carcinoid. Furthermore, this study may help improve diagnosing these special cases in clinical practice to avoid misdiagnosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09391-w.

Prognosis of Patients with Bronchopulmonary Neuroendocrine Neoplasms in a Tertiary Neuroendocrine Tumor Centre of Excellence

INTRODUCTION

The European Neuroendocrine Tumor Society (ENETS) reports variables of prognostic significance in bronchopulmonary neuroendocrine neoplasms (BP-NENs). The aim of this study was to investigate prognostic factors, recurrence-free survival (RFS), and overall survival (OS) for patients with typical carcinoid (TC), atypical carcinoid (AC), and large-cell neuroendocrine carcinoma (LCNEC). Current follow-up practices vary as the evidence is sparse, and we aimed to explore the relevance of routine bronchoscopy in follow-up.

METHODS

This was a cohort study of 208 patients with BP-NENs followed at Aarhus University Hospital in 2008-2019. RFS and OS were determined using the Kaplan-Meier method for the variables such as primary tumor, primary treatment, smoking status, gender, and histological subtypes.

RESULTS

The study included 153 patients with TC, 29 with AC, and 26 with LCNEC. Median follow-up was 48 months. The majority of patients (n = 191) received surgical resection, of which 22 (11%) recurred over time. Seventeen patients had nonsurgical treatment, of which 10 (59%) progressed. The 5-year OS rate was 86% for operated and 9% for nonoperated patients (p < 0.05). Patients with TC had a 5-year OS of 90% compared with 63% and 39% for AC and LCNEC, respectively. As for prognostic factors, nonsmokers did not secure a significant difference in OS compared with current/previous smokers (p = 0.51). In the follow-up period, only 2 (9%) of the 22 recurrences were found on a routine bronchoscopy. Both of these recurrences were also found by diagnostic imaging.

CONCLUSIONS

Surgical treatment, especially, and diagnosis of TC were associated with a good prognosis. Furthermore, our data did not support routine bronchoscopy as part of a follow-up program for bronchial carcinoids.

N-staging in large cell neuroendocrine carcinoma of the lung: diagnostic value of [18F]FDG PET/CT compared to the histopathology reference standard

Background

Large cell neuroendocrine carcinoma of the lung (LCNEC) is a rare entity occurring in less than 4% of all lung cancers. Due to its low differentiation and high glucose transporter 1 (GLUT1) expression, LCNEC demonstrates an increased glucose turnover. Thus, PET/CT with 2-[¹⁸F]-fluoro-deoxyglucose ([¹⁸F]FDG) is suitable for LCNEC staging. Surgery with curative intent is the treatment of choice in early stage LCNEC. Prerequisite for this is correct lymph node staging. This study aimed at evaluating the diagnostic performance of [¹⁸F]FDG PET/CT validated by histopathology following surgical resection or mediastinoscopy. N-staging interrater-reliability was assessed to test for robustness of the [¹⁸F]FDG PET/CT findings.

Methods

Between 03/2014 and 12/2020, 46 patients with LCNEC were included in this single center retrospective analysis. All underwent [¹⁸F]FDG PET/CT for pre-operative staging and subsequently either surgery (n = 38) or mediastinoscopy (n = 8). Regarding the lymph node involvement, sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) were calculated for [¹⁸F]FDG PET/CT using the final histopathological N-staging (pN0 to pN3) as reference.

Results

Per patient 14 ± 7 (range 4–32) lymph nodes were resected and histologically processed. 31/46 patients had no LCNEC spread into the lymph nodes. In 8/46 patients, the final stage was pN1, in 5/46 pN2 and in 2/46 pN3. [¹⁸F]FDG PET/CT diagnosed lymph node metastasis of LCNEC with a sensitivity of 93%, a specificity of 87%, an accuracy of 89%, a PPV of 78% and a NPV of 96%. In the four false positive cases, the [¹⁸F]FDG uptake of the lymph nodes was 33 to 67% less in comparison with that of the respective LCNEC primary. Interrater-reliability was high with a strong level of agreement (κ = 0.82).

Conclusions

In LCNEC N-staging with [¹⁸F]FDG PET/CT demonstrates both high sensitivity and specificity, an excellent NPV but a slightly reduced PPV. Accordingly, preoperative invasive mediastinal staging may be omitted in cases with cN0 disease by [¹⁸F]FDG PET/CT. In [¹⁸F]FDG PET/CT cN1-cN3 stages histological confirmation is warranted, particularly in case of only moderate [¹⁸F]FDG uptake as compared to the LCNEC primary.

Optimal Cut-Off Values of the Positive Lymph Node Ratio and the Number of Removed Nodes for Patients Receiving Resection of Bronchopulmonary Carcinoids: A Propensity Score-Weighted Analysis of the SEER Database

Background

Although lymph node dissection (LND) has been commonly used for patients with bronchopulmonary carcinoids (PCs), the prognostic values of the positive lymph node ratio (PLNR) and the number of removed nodes (NRN) remain unclear.

Methods

Patients with resected PCs were identified in the Surveillance, Epidemiology, and End Results (SEER) database (2010–2015). The optimal cut-off values of the PLNR and NRN were determined by X-tile. The inverse probability of treatment weighting (IPTW) method was used to reduce the selection bias. IPTW-adjusted Kaplan-Meier curves and Cox proportional hazards models were used to compare the overall survival (OS) and cancer-specific survival (CSS) of patients in different PLNR and NRN groups.

Results

The study included 1622 patients. The optimal cut-off values of the PLNR and NRN for survival were 13% and 13, respectively. In both Kaplan-Meier analysis and univariable Cox proportional hazards regression analysis before IPTW, a PLNR ≥13% was significantly associated with worse OS (HR = 3.364, P<0.001) and worse CSS (HR = 7.874, P<0.001). These findings were corroborated by the IPTW-adjusted Cox analysis OS (HR = 2.358, P = 0.0275) and CSS (HR = 8.190, P<0.001) results. An NRN ≥13 was not significantly associated with worse OS in either the Kaplan-Meier or Cox analysis before or after IPTW adjustment. In the Cox proportional hazards analysis before and after IPTW adjustment, an NRN ≥13 was significantly associated with worse CSS (non-IPTW: HR = 2.216, P=0.013; IPTW-adjusted: HR = 2.162, P=0.024).

Conclusion

A PLNR ≥13% could predict worse OS and CSS in patients with PCs and might be an important complement to the present PC staging system. Extensive LND with an NRN ≥13 might have no therapeutic value for OS and may even have an adverse influence on CSS. Its application should be considered on an individual basis.

Long-term survival and recurrence after resection of bronchopulmonary carcinoids: A single-center cohort study of 236 patients

OBJECTIVE

The aim of this study was to determine overall survival and recurrence-free survival after resection of bronchopulmonary carcinoids by means of predominantly minimally invasive surgery and lung-sparing resections. In addition, we aimed to identify prognostic factors for overall survival.

MATERIALS AND METHODS

Retrospective review of consecutive patients operated for bronchopulmonary carcinoids between January 2009 and October 2020 identified from a prospectively collected database.

RESULTS

A total of 236 patients representing 240 cases of bronchopulmonary carcinoids were included. Of these, 212 (88.3 %) were typical carcinoids, while 28 (11.7 %) were atypical carcinoids. A Video-Assisted Thoracoscopic Surgery (VATS) approach was used in 75 % of cases. There was no 30-day mortality. The median follow-up was 5.6 years for overall survival and 4.7 years for recurrence-free survival. 5- and 10-year overall survival rates were 89 % and 71 %, while 5- and 10-year recurrence-free survival rates were 84 % and 71 %. Patients with atypical carcinoids had significantly reduced overall survival and recurrence-free survival rates (HR 3.4; 95 % CI 1.5-7.6; p = 0.003 and HR 5.4; 95 % CI 2.6-11.4; p < 0.001). Independent predictors of overall survival included atypical carcinoid (HR 2.7; 95 % CI 1.2-6.0; p = 0.018) and age > 60 years (HR 2.9; 95 % CI 1.2-7.3; p = 0.021).

CONCLUSION

Surgery for bronchopulmonary carcinoids by means of predominantly VATS and lung-sparing resections provides favorable long-term survival. Atypical carcinoids and age > 60 years are independent predictors of poor overall survival.

Multiple endocrine neoplasia type 1 (MEN-1) and neuroendocrine neoplasms (NENs)

Neuroendocrine neoplasms (NENs) are relatively rare neoplasms with 6.4-times increasing age-adjusted annual incidence during the last four decades. NENs arise from neuroendocrine cells, which release hormones in response to neuronal stimuli and they are distributed into organs and tissues. The presentation and biological behaviour of the NENs are highly heterogeneous, depending on the organ. The increased incidence is mainly due to increased awareness and improved detection methods both in the majority of sporadic NENs (non-inherited), but also the inherited groups of neoplasms appearing in at least ten genetic syndromes. The most important one is multiple endocrine neoplasia type 1 (MEN-1), caused by mutations in the tumour suppressor gene MEN1. MEN-1 has been associated with different tumour manifestations of NENs e.g. pancreas, gastrointestinal tract, lungs, thymus and pituitary. Pancreatic NENs tend to be less aggressive when arising in the setting of MEN-1 compared to sporadic pancreatic NENs. There have been very important improvements over the past years in both genotyping, genetic counselling and family screening, introduction and validation of various relevant biomarkers, as well as newer imaging modalities. Alongside this development, both medical, surgical and radionuclide treatments have also advanced and improved morbidity, quality of life and mortality in many of these patients. Despite this progress, there is still space for improving insight into the genetic and epigenetic factors in relation to the biological mechanisms determining NENs as part of MEN-1. This review gives a comprehensive update of current evidence for co-occurrence, diagnosis and treatment of MEN-1 and neuroendocrine neoplasms and highlight the important progress now finding its way to international guidelines in order to improve the global management of these patients.

Antitumoral Activity of the MEK Inhibitor Trametinib (TMT212) Alone and in Combination with the CDK4/6 Inhibitor Ribociclib (LEE011) in Neuroendocrine Tumor Cells In Vitro

OBJECTIVES

This study assessed the antitumoral activity of the MEK inhibitor trametinib (TMT212) and the ERK1/2 inhibitor SCH772984, alone and in combination with the CDK4/6 inhibitor ribociclib (LEE011) in human neuroendocrine tumor (NET) cell lines in vitro.

METHODS

Human NET cell lines BON1, QGP-1, and NCI-H727 were treated with trametinib or SCH772984, alone and in combination with ribociclib, to assess cell proliferation, cell cycle distribution, and protein signaling using cell proliferation, flow cytometry, and Western blot assays, respectively.

RESULTS

Trametinib and SCH772984, alone and in combination with ribociclib, significantly reduced NET cell viability and arrested NET cells at the G1 phase of the cell cycle in all three cell lines tested. In addition, trametinib also caused subG1 events and apoptotic PARP cleavage in QGP1 and NCI-H727 cells. A western blot analysis demonstrated the use of trametinib alone and trametinib in combination with ribociclib to decrease the expression of pERK, cMyc, Chk1, pChk2, pCDK1, CyclinD1, and c-myc in a time-dependent manner in NCI-H727 and QGP-1 cells.

CONCLUSIONS

MEK and ERK inhibition causes antiproliferative effects in human NET cell lines in vitro. The combination of the MEK inhibitor trametinib (TMT212) with the CDK4/6 inhibitor ribociclib (LEE011) causes additive antiproliferative effects. Future preclinical and clinical studies of MEK inhibition in NETs should be performed.

Diagnostic Value of Conventional PET Parameters and Radiomic Features Extracted from 18F-FDG-PET/CT for Histologic Subtype Classification and Characterization of Lung Neuroendocrine Neoplasms

Aim: To evaluate if conventional Positron emission tomography (PET) parameters and radiomic features (RFs) extracted by 18F-FDG-PET/CT can differentiate among different histological subtypes of lung neuroendocrine neoplasms (Lu-NENs). Methods: Forty-four naïve-treatment patients on whom 18F-FDG-PET/CT was performed for histologically confirmed Lu-NEN (n = 46) were retrospectively included. Manual segmentation was performed by two operators allowing for extraction of four conventional PET parameters (SUVmax, SUVmean, metabolic tumor volume (MTV), and total lesion glycolysis (TLG)) and 41 RFs. Lu-NENs were classified into two groups: lung neuroendocrine tumors (Lu-NETs) vs. lung neuroendocrine carcinomas (Lu-NECs). Lu-NETs were classified according to histological subtypes (typical (TC)/atypical carcinoid (AC)), Ki67-level, and TNM staging. The least absolute shrink age and selection operator (LASSO) method was used to select the most predictive RFs for classification and Pearson correlation analysis was performed between conventional PET parameters and selected RFs. Results: PET parameters, in particular, SUVmax (area under the curve (AUC) = 0.91; cut-off = 5.16) were higher in Lu-NECs vs. Lu-NETs (p < 0.001). Among RFs, HISTO_Entropy_log10 was the most predictive (AUC = 0.90), but correlated with SUVmax/SUVmean (r = 0.95/r = 0.94, respectively). No statistical differences were found between conventional PET parameters and RFs (p > 0.05) and TC vs. AC classification. Conventional PET parameters were correlated with N+ status in Lu-NETs. Conclusion: In our study, conventional PET parameters were able to distinguish Lu-NECs from Lu-NETs, but not TC from AC. RFs did not provide additional information.

Somatostatin Receptor Imaging PET in Neuroendocrine Neoplasm

PET/computed tomography (CT) imaging increasingly is used in neuroendocrine neoplasms (NENs) for diagnosis, staging, monitoring, prognostication, and choosing treatment. Somatostatin PET analog tracers have added to the specificity by obtaining higher affinity to somatostatin receptors with ⁶⁸Ga-labeled or ⁶⁴Cu-labeled DOTA peptides compared with single-photon emission CT imaging isotopes. PET uptake correlates to tumor grade and is an essential part of theranostics with peptide receptor radionuclide treatment. This article focuses on the literature on head-to-head studies and meta-analyses of different combinations of peptide agonists and a few antagonists. Overall, the published data support the diagnostic capability of PET/CT imaging in NENs.

Challenges in Ki-67 assessments in pulmonary large-cell neuroendocrine carcinomas

AIMS

To gather the best available evidence regarding Ki-67% values in large-cell neuroendocrine carcinoma (LCNEC) and determine whether certain cut-off values could serve as a prognostic feature in LCNEC.

METHODS AND RESULTS

Aperio ScanScope AT Turbo, eSlide Manager and ImageScope software (Leica Biosystems) were used to measure Ki-67% in 77 resected LCNEC diagnosed by World Health Organisation (WHO) criteria. Cases were stratified into six classes by 10% Ki-67 increments. Using the Kaplan-Meier method, overall (OS) and disease-free survivals (DFS) were compared by AJCC stage, by six Ki-67% classes and with Ki-67% cut-points ≥20% and ≥40%. Tumours were from 0.9 to 11.5 cm and pathological stages 1-3. The system measured Ki-67% positivity using 4072-44 533 tumour nuclei per case (mean 16610 ± 8039). Ki-67% ranged from 1 to 64% (mean = 26%; median = 26%). Only 16 (21%) tumours had Ki-67% ≥40%. OS ranged from 1 to 298 months (median follow-up = 25 months). DFS ranged from 1 to 276 months (median follow-up = 9 months). OS and DFS differed across AJCC stage (overall log-rank P = 0.038 and P = 0.037). However, neither OS nor DFS significantly correlated with Ki-67% when six or two classes were used with either ≥20% Ki-67 or ≥40% Ki-67 as cut-point. A literature review identified 14 reports meeting our inclusion criteria with ≥10 LCNEC. Reported Ki-67% ranged from 2% to 100%. Problems contributing to variability in Ki-67% measurements are discussed.

CONCLUSION

Our findings caution against a blanket use of 20%, 40% or other Ki-67% cut-points for LCNEC diagnosis or prognostication.

Pulmonary large cell neuroendocrine carcinoma (LCNEC) with confirmed liver metastases negative on 18F-FDG and 68Ga-DOTATATE PET

Lung neuroendocrine neoplasms (NENs) encompass the low-, intermediate-, and high-grade entities. Differentiated NENs overexpress somatostatin receptors, which are targeted by ⁶⁸Ga-DOTA-conjugated peptides in molecular imaging with positron emission tomography. Less differentiated NENs may have lost their expression of somatostatin receptors and thus show lower uptake of ⁶⁸Ga-DOTA-peptides; however, these tumors express GLUT-1 and can be imaged with (18)F-fluordeoxyglucose (FDG).

We report the case of a 72-year-old patient with a poorly differentiated, high grade lung NEN, which was ¹⁸F-FDG-positive at initial diagnosis. After treatment and remission, the patient had histologically confirmed relapse in the liver. Interestingly, these hepatic metastases did not demonstrated radiopharmaceutical uptake at neither ¹⁸F-FDG nor ⁶⁸Ga-DOTATATE positron emission tomography/computed tomography.

Neuroendocrine syndrome in bronchial carcinoid tumors

Pulmonary carcinoid tumors represent bronchopulmonary neuroendocrine neoplasms which might synthetize serotonin, histamine, bombesin or other types of hormones responsible for the development of a broad spectrum of signs and symptoms, known as carcinoid syndrome. Data of 98 patients submitted to surgery for bronchial carcinoid tumors in the Thoracic Surgery Clinic of the 'Marius Nasta' Institute of Pneumophtisiology between 2014 and 2018 were retrospectively reviewed. All patients were submitted to paraclinical tests, imagistic studies (computed tomography or magnetic resonance imaging), bronchoscopy and biopsy in order to have a positive diagnostic of pulmonary carcinoid. The most common clinical symptoms at the time of presentation were: Persistent cough followed by dyspnea and recurrent pulmonary infections. The main neuroendocrine syndromes found were Cushing and Carcinoid Syndrome. All patients were submitted to surgery with curative intent consisting of wedge resection (in 4 cases, 4.08%), lobectomy (in 79 cases, 80.61%), bilobectomy (in 5 cases, 5.1%) and pneumonectomy respectively (in 10 cases, 10.2%). In all cases neuroendocrine specific symptoms disappeared once the carcinoid tumor was removed. In conclusion, bronchial carcinoid tumors have a positive outcome in most cases. Specific neuroendocrine markers as well as neuroendocrine syndrome disappears once the tumor is removed.

Lung carcinoids with high proliferative activity: Further support for the identification of a new tumor category in the classification of lung neuroendocrine neoplasms

Highly proliferative lung carcinoids (HPLC) have been recently reported but information about this subset remains scarce.

OBJECTIVES

Clinical and pathological data of 630 patients with lung carcinoids (LC) referred to Gustave Roussy Institute (GR) and European Institute of Oncology (IEO) were retrospectively reviewed to select HPLC and analyze their frequency, behavior and compare their outcome to conventional LC with Ki-67 ≤ 20 % and mitotic count (MC)≤10/2 mm².

MATERIALS AND METHODS

Selection criteria were: diagnosis of LC confirmed by local pathologist, and available clinical and follow-up data. Patients with Ki-67 > 20 % and/or MC > 10/ 2 mm2 in primary or metastatic specimens were identified as HPLC.

RESULTS

30/514 patients (6%) met the selection criteria of HPLC. Based on primary tumor evaluation, 22/25 (88 %) were classified as atypical carcinoids (AC). Median MC was 4.5/2 mm² (1-11) 6/2 mm² (3-15) in primary tumors and metastasis, respectively. Median Ki-67 was respectively 23 % (15-65) and 25 % (8-60). Recurrence rate was 66 % (12/18) in HPLC and 9 % (33/352) in conventional LC. Median RFS was 24 (10-NR) months in HPLC, 288 (141-NR) months in LC with Ki-67 index≤5 % and NR (148-NR) months in LC with Ki-67 6-20% (p < 001). Median OS was 203 (83-NR) months in LC with Ki-67 index≤5%, 101 (79-NR) months in LC with Ki-67 index 6-20 % and 53 (39-NR) months in HPLC (p = 002). Among 20 metastatic patients with HPLC, median PFS under platinum-based chemotherapy, everolimus, alkylating-based chemotherapy, FOLFOX and PRRT was 5.1 (95 % CI 0.7-9.4), 12.1(95 %CI 0.3-24), 6.8 (95 % CI 0-14.9), 10.2 (95 % CI 0.4-19.9) and 14.2 months (95 % CI 0-30) respectively. Best response was stable disease (SD) under platinum-based chemotherapy and partial response (PR) under alkylating-based chemotherapy and FOLFOX.

CONCLUSION

This study confirms the existence and rarity of HPLC. Their characteristics and clinical behavior are more similar to LC rather than neuroendocrine carcinomas (NECs), suggesting that this entity could be managed accordingly.