Advanced typical and atypical carcinoid tumours of the lung: management recommendations

Myc family proteins: Molecular drivers of tumorigenesis and resistance in neuroendocrine tumors

Neuroendocrine cancers are a diverse and poorly understood collection of malignancies derived from neuroendocrine cells throughout the body. These cancers uniquely exhibit properties of both the nervous and endocrine systems. Only a limited number of genetic driver mutations have been identified in neuroendocrine cancers, however the mechanisms of how these genetic aberrations alter tumor biology remain elusive. Recent studies have implicated the MYC family of transcription factors as important oncogenic factors in neuroendocrine tumors. We take a systematic approach to understand the roles of the MYC family (c-MYC, n-MYC, l-MYC) in the tumorigenesis of neuroendocrine cancers of the lung, GI tract, pancreas, kidney, prostate, pediatric neuroblastoma, and adrenal glands. Reflecting the complexity of neuroendocrine cancers, we highlight the roles of the MYC family in deregulating the cell cycle and transcriptional networks, invoking cellular plasticity, affecting proliferation capacity, aiding in chromatin remodeling, angiogenesis, metabolic changes, and resistance mechanisms. Depicting the diversity of neuroendocrine cancers, we suggest new approaches in understanding the underlying tumorigenic processes of neuroendocrine cancers from the perspective of MYC.

Capecitabine and temozolomide or temozolomide alone in patients with atypical carcinoids

BACKGROUND

Lung neuroendocrine neoplasms (NENs) represent about 20% of all lung cancers. Few therapeutic options are available for atypical carcinoids (ACs). Single-agent temozolomide (TEM) is active in lung NENs, but whether the addition of capecitabine (CAPTEM) is associated with improved outcomes, is unknown. We sought to investigate the TEM-based therapies (TEM or CAPTEM) in patients with advanced AC.

MATERIAL AND METHODS

This was a retrospective analysis of prospectively collected data from patients with AC of the lung referred to our institution from January 2003 to January 2023 who have received chemotherapy with either TEM or CAPTEM as any line treatment. Primary endpoint was progression free survival (PFS), secondary endpoints included overall response rate (ORR) and overall survival (OS).

RESULTS

In this study we included 31 patients with advanced AC. Median Ki-67 was 14.4% (3-30). CAPTEM in 17 patients (54.8%), while TEM was administered in 14 patients (45.2%). Overall, ORR was 39% (N = 12/31, all partial responses), while median PFS and OS were 57.4 months (95%CI: 43.2-71.7) and 24.4 months (95% confidence interval [95%CI]: 14.7-34.1). Median PFS was 33.9 months (15.6-52.1) in the CAPTEM group, while it was 15.5 (7.3-23.8) in the TEM group (p = 0.047). When adjusting for potential confounding factors, treatment with TEM vs CAPTEM retained its independent association with an increased risk of progression (HR: 4.01 [95%CI: 1.18-13.68]; p = 0.027).

CONCLUSIONS

Treatment with CAPTEM is associated with longer PFS than TEM alone in patients with AC. Prospective studies with larger sample size are needed to validate this finding.

Primary Typical Carcinoid Tumor of the Sphenoid Sinus: Case Report and Literature Review

Carcinoid tumors, a subset of neuroendocrine tumors, are exceptionally rare in the nose and paranasal sinuses. Owing to their indolent nature, nonspecific clinical symptoms, and variable radiological features, treatment of carcinoid tumors remains a challenge. In this report, we present a case involving a 49 year-old female patient who presented with a carcinoid tumor originating in the sphenoid sinuses. The patient underwent a surgical resection of the tumor and has been followed up in the outpatient clinic, recurrence-free. In addition, we performed an English literature search of cases of carcinoid tumor of the nose and paranasal sinuses from January 2000 through January 2024 in the MEDLINE, EMBASE, and Scopus databases. Furthermore, the clinical characteristics and interventions of carcinoid tumor of the nose and paranasal sinuses were discussed, which might enhance the early diagnosis and provide appropriate management strategies.

Neuroendocrine Neoplasms of the Lungs, Thyroid, and Thymus

Neuroendocrine neoplasms (NENs) comprise a group of tumours that can develop in various internal organs, but in this review, we will describe only those arising in the lungs, thyroid, and thymus. Pulmonary neuroendocrine neoplasms (pulmonary NENs) account for approximately 25% of all lung cancers. They are classified into four groups of tumours: typical carcinoids (TCs), atypical carcinoids (ACs), small cell lung carcinoma, and large cell lung carcinoma. This review focuses on TC and AC. The treatment consists mainly of radiotherapy, chemotherapy, and surgical resection, but novel drugs like atezolizumab are also utilised. The most common neuroendocrine neoplasm of the thyroid gland is medullary thyroid carcinoma (MTC), which commonly possesses RET protooncogene mutations. MTC is treated by a total thyroidectomy. Recently, tyrosine kinase inhibitors (TKIs) have emerged as an effective treatment option for patients with advanced MTC. Neuroendocrine tumours of the thymus (NETTs) are also being treated with a radical surgery.

A case of carcinoid syndrome after CT guided lung biopsy of a neuroendocrine tumor

Carcinoid tumors of the lung are an uncommon malignancy that can rarely lead to carcinoid syndrome. Carcinoid tumors represent less than 1% of all lung cancers. This case describes a rare presentation in which a previously asymptomatic woman began to experience tachycardia, shortness of breath, and anxiety after biopsy of a pulmonary carcinoid tumor. Chest CT, histology, and clinical course supported the diagnosis and the patient's symptoms quickly resolved with medication. Ultimately, surgical removal of the tumor led to complete resolution of symptoms.

Head-to-head: Should Ki67 proliferation index be included in the formal classification of pulmonary neuroendocrine neoplasms?

The reporting of lung neuroendocrine neoplasms (NENs) according to the 2021 World Health Organisation (WHO) is based on mitotic count per 2 mm2, necrosis assessment and a constellation of cytological and immunohistochemical details. Accordingly, typical carcinoid and atypical carcinoid are low- to intermediate-grade neuroendocrine tumours (NETs), while large-cell neuroendocrine carcinoma (NEC) and small-cell lung carcinoma are high-grade NECs. In small-sized diagnostic material (cytology and biopsy), the noncommittal term of carcinoid tumour/NET not otherwise specified (NOS) and metastatic carcinoid NOS have been introduced with regard to primary and metastatic diagnostic settings, respectively. Ki-67 antigen, a well-known marker of cell proliferation, has been included in the WHO classification as a non-essential but desirable criterion, especially to distinguish NETs from high-grade NECs and to delineate the provisional category of carcinoid tumours/NETs with elevated mitotic counts (> 10 mitoses per mm2) and/or Ki-67 proliferation index (≥ 30%). However, a wider use of this marker in the spectrum of lung NENs continues to be highly reported and debated, thus witnessing a never-subsided attention. Therefore, the arguments for and against incorporating Ki-67 in the classification and clinical practice of these neoplasms are discussed herein in detail.

Antitumor Activity of Axitinib in Lung Carcinoids: A Preclinical Study

Lung carcinoids (LCs) comprise well-differentiated neuroendocrine tumors classified as typical (TCs) and atypical (ACs) carcinoids. Unfortunately, curative therapies remain elusive for metastatic LCs, which account for 25-30% of cases. This study evaluated the antitumor activity of axitinib (AXI), a second-generation tyrosine kinase inhibitor selectively targeting vascular endothelial growth factor receptors (VEGFR-1, VEGFR-2, VEGFR-3) in human lung TC (NCI-H727, UMC-11, NCI-H835) and AC (NCI-H720) cell lines. In vitro and in vivo (zebrafish) assays were performed following AXI treatment to gather several read-outs about cell viability, cell cycle, the secretion of proangiogenic factors, apoptosis, tumor-induced angiogenesis and migration. AXI demonstrated relevant antitumor activity in human LC cells, with pronounced effects observed in UMC-11 and NCI-H720, characterized by cell cycle perturbation and apoptosis induction. AXI significantly hindered tumor induced-angiogenesis in Tg(fli1a:EGFP)y1 zebrafish embryos implanted with all LC cell lines and also reduced the invasiveness of NCI-H720 cells, as well as the secretion of several proangiogenic factors. In conclusion, our study provides initial evidence supporting the potential anti-tumor activity of AXI in LC, offering a promising basis for future investigations in mammalian animal models and, eventually, progressing to clinical trials.

Tracheal atypical solitary carcinoid in a so-called "difficult asthma": a diagnostic challenge

This report describes the case of a 46-year-old non-smoker housewife. She presented to our attention with a diagnosis of "difficult asthma" from another center in the previous two years. She had no allergies and had not been exposed to an excessive amount of noxious stimuli. Her chronic respiratory symptoms (dyspnea on exertion with wheezing) remained uncontrolled despite maximal anti-asthmatic inhaled therapy. A high-resolution computed tomography scan was performed to further investigate other pulmonary diseases that mimic asthma. It revealed a pedunculated endotracheal lesion with regular borders that obstructed 90% of the tracheal lumen. The lesion was removed via rigid bronchoscopy with laser endobronchial; histological examination revealed the presence of an atypical carcinoid. Atypical carcinoids are a rare subtype of neuroendocrine lung tumor that accounts for 2% of all thoracic malignancies. They frequently arise from the central airways and cause obstructive symptoms such as coughing, wheezing, chest pain, or recurrent obstructing pneumonia, which is caused by central airway obstruction. Clinical onset is gradual and characterized by non-specific symptoms, which frequently result in misdiagnosis. As a result, in a young patient with progressive dyspnea, chronic cough, and wheezing that is not responding to anti-asthmatic treatment, second-level investigations are required and may lead to a definite diagnosis, allowing the appropriate course of treatment to begin.

Growth Rates of Pulmonary Carcinoid Tumors and Hamartomas

BACKGROUND

Pulmonary nodule growth is often measured by volume doubling time (VDT), which may guide management. Most malignant nodules have a VDT of 20 to 400 days, with longer VDTs typically observed in indolent nodules. We assessed the utility of VDT in differentiating pulmonary carcinoids and hamartomas.

METHODS

A review was performed from January 2012 to October 2021 to identify patients with pathologic diagnoses and at least 2 chest computed tomography scans obtained 6 or more months apart. Visualization software was used to segment nodules and calculate diameter and volume. Volume doubling time was calculated for scans with 1-mm slices. For the remainder, estimated nodule volume doubling time (eVDT) was calculated using nodule diameter. Volume doubling times/eVDTs were placed into growth categories: less than 400 days; 400-600 days; and more than 600 days.

RESULTS

Sixty nodules were identified, 35 carcinoids and 25 hamartomas. Carcinoids were larger than hamartomas (median diameter, 13.5 vs 11.5 mm; P = 0.05). For carcinoid tumors, median VDT (n = 15) was 1485 days, and median eVDT (n = 32) was 1309 days; for hamartomas, median VDT (n = 8) was 2040 days and median eVDT (n = 25) was 2253 days. Carcinoid tumor eVDT was significantly shorter than hamartomas ( P = 0.03). By growth category, 1 of 25 hamartomas and 5 of 35 carcinoids had eVDT less than 400 days and 24 of 25 hamartomas and 27 of 35 carcinoids had eVDT more than 600 days. Of 4 carcinoid tumors with metastases, 2 had eVDT less than 400 days and 2 had eVDT more than 600 days.

CONCLUSIONS

Growth rate was not a reliable differentiator of pulmonary hamartomas and carcinoids. Slow growing carcinoids can metastasize. Radiologists should be cautious when discontinuing computed tomography follow-up based on growth rates alone.

Nanoparticles advanced from preclinical studies to clinical trials for lung cancer therapy

Lung cancer is the leading cause of cancer mortality. As a heterogeneous disease, it has different subtypes and various treatment modalities. In addition to conventional surgery, radiotherapy and chemotherapy, targeted therapy and immunotherapy have also been applied in the clinics. However, drug resistance and systemic toxicity still cannot be avoided. Based on the unique properties of nanoparticles, it provides a new idea for lung cancer therapy, especially for targeted immunotherapy. When nanoparticles are used as carriers of drugs with special physical properties, the nanodrug delivery system ensures the accuracy of targeting and the stability of drugs while increasing the permeability and the aggregation of drugs in tumor tissues, showing good anti-tumor effects. This review introduces the properties of various nanoparticles including polymer nanoparticles, liposome nanoparticles, quantum dots, dendrimers, and gold nanoparticles and their applications in tumor tissues. In addition, the specific application of nanoparticle-based drug delivery for lung cancer therapy in preclinical studies and clinical trials is discussed.

A carcinoid tumor of the middle ear masquerading as a glomus tympanicum presenting with temporal lobe hemorrhage in a 70-year-old woman: Case report and review of the literature

BACKGROUND

Paragangliomas in the central nervous system account for 0.6% of all head and neck neoplasms, with glomus tympanicum being the most common middle ear tumor. Carcinoid tumors are neuroendocrine tumors, representing less than 1% of neuroendocrine neoplasms in the middle ear. Misdiagnoses have been reported in the literature regarding glomus and carcinoid tumors, however, none have been in the central nervous system or middle ear.

CASE DESCRIPTION

A 70-year-old female with a history of left temporal lobe tumor underwent unsuccessful resection due to intraoperative bleeding at an outside institution. However, biopsy prior to aborting the case led to the diagnosis of paraganglioma. Eight years postoperatively, the patient presented at our institution with acute confusion, aphasia, and altered mental status. Imaging revealed a 4 cm left temporal intraparenchymal hematoma at the known tumor site with concern for intracranial tumor extension. Surgical resection was performed and previous symptoms resolved. Final pathology revealed a Grade II atypical carcinoid tumor with an unusually high Ki-67 of 50%.

CONCLUSIONS

Carcinoid tumors of the middle ear constitute a differential diagnosis for patients presenting with temporal lobe hemorrhage. A combination of immunohistochemical staining with electron microscopy can assist in differentiating the tumor types. This atypical presentation for a carcinoid tumor in the middle ear suggests the need to consider carcinoid as the diagnosis in patients with a middle ear tumor invading into the temporal lobe and causing hemorrhage. These tumors may demonstrate an unusually high Ki-67 rate, in which case they should be treated aggressively.

Modeling Lung Carcinoids with Zebrafish Tumor Xenograft

Lung carcinoids are neuroendocrine tumors that comprise well-differentiated typical (TCs) and atypical carcinoids (ACs). Preclinical models are indispensable for cancer drug screening since current therapies for advanced carcinoids are not curative. We aimed to develop a novel in vivo model of lung carcinoids based on the xenograft of lung TC (NCI-H835, UMC-11, and NCI-H727) and AC (NCI-H720) cell lines and patient-derived cell cultures in Tg(fli1a:EGFP)y1 zebrafish embryos. We exploited this platform to test the anti-tumor activity of sulfatinib. The tumorigenic potential of TC and AC implanted cells was evaluated by the quantification of tumor-induced angiogenesis and tumor cell migration as early as 24 h post-injection (hpi). The characterization of tumor-induced angiogenesis was performed in vivo and in real time, coupling the tumor xenograft with selective plane illumination microscopy on implanted zebrafish embryos. TC-implanted cells displayed a higher pro-angiogenic potential compared to AC cells, which inversely showed a relevant migratory behavior within 48 hpi. Sulfatinib inhibited tumor-induced angiogenesis, without affecting tumor cell spread in both TC and AC implanted embryos. In conclusion, zebrafish embryos implanted with TC and AC cells faithfully recapitulate the tumor behavior of human lung carcinoids and appear to be a promising platform for drug screening.

Advanced atypical lung carcinoid tumour successfully treated with carboplatin, etoposide and atezolizumab: A case report

Atypical carcinoid tumours are relatively rare among lung cancers. Surgery is regarded as standard treatment for localized cases, but there is little established evidence on treatment strategies for advanced cases. Moreover, the efficacy of immune checkpoint inhibitors for advanced carcinoid tumours is unclear. Here, we report a case of a patient with an atypical carcinoid tumour in whom successful disease control was achieved with the use of combined cytotoxic chemotherapy and immunotherapy.

SURGICAL APPROACH OF LUNG CARCINOID TUMORS

Bronchial carcinoid tumours (typical and atypical carcinoid) are endobronchial tumours that can benefit from both local endobronchial treatment and surgical treatment. Given their relatively good prognosis compared to the other two forms of pulmonary neuroendocrine tumours, there is a current concern about the implications of lymph node involvement as well as the identification of new prognostic factors to shape the treatment of these patients in the future.

Molecular Pathology of Lung Cancer

This overview of the molecular pathology of lung cancer includes a review of the most salient molecular alterations of the genome, transcriptome, and the epigenome. The insights provided by the growing use of next-generation sequencing (NGS) in lung cancer will be discussed, and interrelated concepts such as intertumor heterogeneity, intratumor heterogeneity, tumor mutational burden, and the advent of liquid biopsy will be explored. Moreover, this work describes how the evolving field of molecular pathology refines the understanding of different histologic phenotypes of non-small-cell lung cancer (NSCLC) and the underlying biology of small-cell lung cancer. This review will provide an appreciation for how ongoing scientific findings and technologic advances in molecular pathology are crucial for development of biomarkers, therapeutic agents, clinical trials, and ultimately improved patient care.

Cushing syndrome secondary to a mediastinal carcinoid tumor: a case report

Neuroendocrine tumors (NET) are a rare and diverse set of malignancies that can develop anywhere within the body. ACTH-producing mediastinal NETs often originate from the thymus in the anterior mediastinum and are very rare. Primary diagnostic modalities for NETs include CT scan, MRI, scintigraphy, and Ga-DOTA PET scan. Here we report a case of a young male without any past medical history presenting with hypercortisolism secondary to a middle mediastinal typical carcinoid tumor. The patient underwent a successful resection which reduced serum ACTH levels. To the best of our knowledge, this is the first case of Cushing syndrome caused by a middle mediastinal NET.

Treatment of Pulmonary Carcinoid Tumors With Bronchoscopic Cryotherapy: A 28-Year Single-center Experience

BACKGROUND

Pulmonary carcinoids are rare tumors originating from neuroendocrine cells in the lungs. Because of their potentially infiltrative nature, surgical resection remains the treatment of choice. However, not all patients with technically resectable disease will be able to undergo surgery, primarily because of poor lung function or medical co-morbidities. Centrally located, intraluminal tumors have been reported to be amenable to bronchoscopic treatment. We specifically examined the role of cryotherapy in the treatment of bronchial carcinoid tumors.

METHODS

Sixty-three patients (52.38% female) who underwent a combined total of 243 cryotherapy procedures for treatment of bronchial carcinoid between 1992 and 2020 in our institution were included in the study. Following discussion in multidisciplinary meetings, patients were considered for first-line cryotherapy when lung resection was deemed not possible or when they had rejected surgery.

RESULTS

Cryotherapy resulted in complete remission in 21 (33.33%) patients with maximum tumor diameter less than 20 mm (mean: 11.08 mm, 95% confidence interval: 8.76-13.40), and allowed 22 (34.92%) patients with larger lesions (mean: 24.04 mm, 95% confidence interval: 18.78-29.30) to proceed with parenchymal sparing resections. Marked symptomatic relief (P<0.001) was reported by 58 (92.06%) patients. The median follow-up was 33 months (range: 0 to 243 mo). One (1.59%) patient was diagnosed with recurrence in a contralateral lobe 3 years after surgery and was treated with radiofrequency ablation.

CONCLUSIONS

In the absence of a definitive randomized controlled trial comparing bronchoscopic treatment with surgical resection, we provide evidence on the safety and efficacy of cryotherapy and encourage wider adoption of this inexpensive and minimally invasive technique for treatment of bronchial carcinoids.

The Ki-67 antigen in the new 2021 World Health Organization classification of lung neuroendocrine neoplasms

Prof. Rosai's work has permeated the surgical pathology in many fields, including the 2017 World Health Organization classification on tumors of endocrine organs and pulmonary neuroendocrine cell pathology, with stimulating contributions which have also anticipated the subsequent evolution of knowledge. Among the many studies authored by Prof. Rosai, we would like to recall one of which whose topic has been encased in the new 2021 World Health Organization classification on lung tumors. This is an eminently practical paper dealing with the use of the proliferation antigen Ki-67 in lung neuroendocrine neoplasms. While these neoplasms are primarily ranked upon histologic features and Ki-67 labeling index does not play any role in classification, diagnostic dilemmas may however arise in severely crushed biopsy or cytology samples where this marker proves helpful to avoid misdiagnoses of carcinoids as small cell carcinoma. Another application of Ki-67 labeling index endorsed by the 2021 World Health Organization classification regards, alongside mitotic count, the emerging recognition of lung atypical carcinoids with increased mitotic or proliferation rates, whose biological boundaries straddle a subset of large cell neuroendocrine carcinoma.

This article focuses on these two practical applications of the proliferation marker Ki-67 in keeping with the 2021 World Health Organization classification, which provides standards for taxonomy, diagnosis and clinical decision making in lung neuroendocrine neoplasm patients.

Lung cancer prediction by Deep Learning to identify benign lung nodules

INTRODUCTION

Deep Learning has been proposed as promising tool to classify malignant nodules. Our aim was to retrospectively validate our Lung Cancer Prediction Convolutional Neural Network (LCP-CNN), which was trained on US screening data, on an independent dataset of indeterminate nodules in an European multicentre trial, to rule out benign nodules maintaining a high lung cancer sensitivity.

METHODS

The LCP-CNN has been trained to generate a malignancy score for each nodule using CT data from the U.S. National Lung Screening Trial (NLST), and validated on CT scans containing 2106 nodules (205 lung cancers) detected in patients from from the Early Lung Cancer Diagnosis Using Artificial Intelligence and Big Data (LUCINDA) study, recruited from three tertiary referral centers in the UK, Germany and Netherlands. We pre-defined a benign nodule rule-out test, to identify benign nodules whilst maintaining a high sensitivity, by calculating thresholds on the malignancy score that achieve at least 99 % sensitivity on the NLST data. Overall performance per validation site was evaluated using Area-Under-the-ROC-Curve analysis (AUC).

RESULTS

The overall AUC across the European centers was 94.5 % (95 %CI 92.6-96.1). With a high sensitivity of 99.0 %, malignancy could be ruled out in 22.1 % of the nodules, enabling 18.5 % of the patients to avoid follow-up scans. The two false-negative results both represented small typical carcinoids.

CONCLUSION

The LCP-CNN, trained on participants with lung nodules from the US NLST dataset, showed excellent performance on identification of benign lung nodules in a multi-center external dataset, ruling out malignancy with high accuracy in about one fifth of the patients with 5-15 mm nodules.

Primary Mediastinal Neuroendocrine Tumor: A Case of Atypical Carcinoid

Primary mediastinal neuroendocrine tumor (PMNET) is an extremely rare clinical entity and few cases have been described in the literature. Here, we report a histologically confirmed rare PMNET case of a 66-year-old male patient with a mass detected in the anterior upper mediastinum by chest high-resolution computed tomography (HRCT). Early detection and surgical intervention of this neoplasm are critical for long term survival, though the tumor is associated with a dismal outcome.

Anterior mediastinal large cell neuroendocrine carcinoma with elevated AFP: A case report and review

Large cell neuroendocrine carcinoma (LCNEC) is a rare and aggressive cancer that typically presents in the lung. The current case report describes a 56 year old male who presented to Strong Memorial Hospital with progressive dyspnea and was revealed to have a large anterior mediastinal tumor with metastases to axillary, hilar and mediastinal lymph nodes. Tumor marker results revealed an elevated plasma level of α-fetoprotein (AFP), which initially pointed towards a diagnosis of teratoma, but the tumor stained positive for neuroendocrine markers CD56, chromogranin, and synaptophysin on biopsy, consistent with LCNEC. AFP-positive tumor cells were identified, and no alternate cause for the elevated AFP was identified. The patient underwent genetic testing revealing the tumor to be ALK, ROS1, KRAS, BRAF and EGFR wild type. The patient received 6 cycles of chemotherapy with cisplatin (80 mg/m²) and etoposide (100 mg/m²) and then radiation with an initial minor response. The patients course was complicated by the development of superior vena cava syndrome requiring emergency stenting. The results of the current case suggest that AFP may be worthy of further exploration as a potential tumor marker in LCNEC.

Diagnosis and management of small pulmonary atypical carcinoid tumor associated with Cushing syndrome

Ectopic adrenocorticotropic hormone (ACTH) syndrome is rare and identification of its source is often challenging. We report the case of an ectopic Cushing syndrome in a young adult male secondary to an occult ACTH producing atypical carcinoid tumor. Extensive biochemical and imaging workup was unrevealing. The diagnosis was aided by Ga-DOTA PET scan demonstrating a suspicious left upper lobe lung nodule. The patient underwent video-assisted thoracoscopic exploration with wedge resection and mediastinal lymphadenectomy of a T2aN2M0 atypical carcinoid, resulting in the normalization of ACTH levels and complete resolution of symptoms. The role of a Ga-DOTA PET scan in diagnosing pulmonary carcinoid tumors and their management are discussed.

Theranostic implications of molecular imaging phenotype of well-differentiated pulmonary carcinoid based on 68Ga-DOTATATE PET/CT and 18F-FDG PET/CT

PURPOSE

This study aimed to analyse the molecular imaging (MI) phenotype of typical carcinoid (TC) and atypical carcinoid (AC) by ⁶⁸Ga-DOTATATE (GaTATE) and ¹⁸F-FDG (FDG) PET/CT with the emphasis on its potential theranostic implications for peptide receptor radionuclide therapy (PRRT).

METHODS

Retrospective review of patients with biopsy-proven TC or AC undergoing both GaTATE and FDG PET/CT at presentation. Based on correlative CT or MRI, positive lesions on either scan were defined by uptake above liver parenchyma. Per patient MI phenotypic pattern was classified as score 1, if all lesions were negative on both scans; score 2, if all were GaTATE positive/FDG negative; score 3, if all lesions were GaTATE positive but some or all were also FDG positive and score 4, if there were any GaTATE negative/FDG positive lesions. Scores 1 and 4 were deemed unsuitable for PRRT.

RESULTS

Of 56 patients (median age 66.5 years, 32 female), 22 had TC, and 34 had AC. Distant metastases were seen in 32% of TC and 94% of AC. At a median follow-up of 37 months for TC and 38 months for AC, 100% and 63% were alive, respectively. Median OS for AC was 56 months (95% CI 43, not reached [NR]), and TC was NR. On inter-patient dual-tracer analysis, scores 1, 2, 3 and 4 were 23%, 18%, 36% and 23% in TC and 3%, 15%, 32% and 50% in AC, respectively. In 16 patients (score 2, N = 3; score 3, N = 12; score 4, N = 1) who were treated with PRRT, disease control rate at 3 months and OS were, 85% and 54.6 months (95% CI 44-70), respectively.

CONCLUSIONS

TC and AC showed a wide inter-patient phenotypic heterogeneity on GaTATE and FDG with around half of patients (46% TC and 53% AC) having an unsuitable phenotype for PRRT. Dual-tracer MI phenotype can be used to select the most suitable patients for PRRT.

miR375-3p Distinguishes Low-Grade Neuroendocrine From Non-neuroendocrine Lung Tumors in FFPE Samples

Lung cancer is still one of the leading cause of death worldwide. The clinical variability of lung cancer is high and drives treatment decision. In this context, correct discrimination of pulmonary neuroendocrine tumors is still of critical relevance. The spectrum of neuroendocrine tumors is various, and each type has molecular and phenotypical differences. In order to advance in the discrimination of neuroendocrine from non-neuroendocrine lung tumors, we tested a series of 95 surgically resected and formalin-fixed paraffin embedded lung cancer tissues, and we analyzed the expression of miR205-5p and miR375-3p via TaqMan RT-qPCR. Via a robust mathematical approach, we excluded technical outliers increasing the data reproducibility. We found that miR375-3p levels are higher in low-grade neuroendocrine lung tumor samples compared to non-neuroendocrine lung tumors. However, miR375-3p is not able to distinguish among different types of neuroendocrine lung tumors. In this work, we provide a new molecular marker for distinguishing non-neuroendocrine from low-grade neuroendocrine lung tumors samples establishing an easy miRNA score to be used in clinical settings, enabling the pathologist to classify more accurately lung tumors biopsies, which may be ambiguously cataloged in routine examination.

Atypical carcinoid: A rare finding of a man with mediastinal mass: A case report

The present case report describes a case of mediastinal atypical carcinoid and a favorable outcome linked with the treatment. Mediastinal atypical carcinoid is a rare and aggressive type of neuroendocrine tumor. A 56-year-old man was admitted at the Respiratory Department due to intermittent tightness of the chest for 1 month. An initial diagnosis of a mass in the left anterior mediastinum was conducted using CT scan and immunohistochemistry. Laboratory data revealed the following values: Neuron Specific Enolase of 62.13 ng/ml (reference range, 0-40 ng/ml); CYFRA21 of 3.01 ng/ml (reference range, 0-3.3 ng/ml); CEA of 4.22 (0-6.5) ng/ml; SCC of 0.5 (0-1.5) ng/ml; CA125 of 67.24 (0-35) U/ml; AFP of 23 (0-25) U/ml; CRP of 96.7 (0-10) mg/l; PCT <0.05 (0-0.05) ng/ml; and ESR of 48 (0-20) mm/h. Tissue pathology revealed tumor cells with small cell pattern, and cell proliferation activity was 10%. Combined chemotherapy with bevacizumab (0.4 g, qd, once every 21 days) and capecitabine (0.15 g, Bid, Po) and timozolamine (0.34 mg, qd, po) was administered for 6 cycles. After the patient was given chemotherapy, the symptoms and CT exhibited improvement. On March 11, 2018, the lesion progressed into the lymph and pleura. The patient was commenced on radiotherapy and new chemotherapeutic regimen etoposide (0.5 g)-carboplatin (0.4 g)-bevacate (0.4 g). Another CT scan was performed after a month which revealed a substantial decrease in tumor size. Hence, a CT scan was performed for this patient who further revealed a decrease in tumor size. Currently patients are treated with bevacizumab maintenance therapy. Further studies of conservative treatment of chemotherapy and radiotherapy may provide a treatment to improve atypical carcinoid.

Méthodes diagnostiques et stratégie thérapeutique des TNE pulmonaires (tumeurs carcinoïdes typiques et atypiques)

Les carcinoïdes bronchiques typiques ou atypiques sont des tumeurs rares. La prise en charge des formes localisées repose essentiellement sur la chirurgie, et leur pronostic reste bon. Le traitement des formes métastatiques demeure difficile et repose sur un niveau de preuve faible. De nouveaux traitements émergent (évérolimus, lutathérapie), mais leur place respective dans l’algorithme thérapeutique est à préciser. L’accès à l’expertise et à la recherche clinique via les réseaux RENATEN-TENpath doit être favorisé.

Multiple Assays to Determine Methylguanine-Methyltransferase Status in Lung Carcinoids and Correlation with Clinical and Pathological Features

BACKGROUND

O6-methylguanine-methyltransferase (MGMT) is a key enzyme for the DNA repair machinery strongly associated with response to alkylating agents in different tumors. Data on its expression and related clinical impact in neuroendocrine tumors are limited to the gastro-entero-pancreatic system, with controversial results in terms of prognostic or predictive value. In lung carcinoids, although clinical efficacy of alkylating agents has been shown in small studies, very few data to date are available on MGMT status.

OBJECTIVE

To assess MGMT status in lung carcinoids using multiple assays and to compare data with major clinical and pathological features.

METHODS

A retrospective series of 95 lung carcinoids and 51 control cases of high-grade neuroendocrine lung carcinomas was analyzed for MGMT promoter methylation, MGMT gene expression, and MGMT protein expression using pyrosequencing, quantitative real-time PCR, and immunohistochemistry, respectively.

RESULTS

MGMT protein expression was inversely correlated with MGMT promoter methylation and positively with MGMT gene expression. MGMT promoter methylation progressively increased from carcinoids to high-grade carcinomas. In the carcinoid group, decreased MGMT gene expression was significantly associated with aggressive features (atypical histotype, grade G2, larger tumor size, higher T stage, and positive nodal status) but not with survival. MGMT promoter methylation was associated with lower stage and negative nodal status.

CONCLUSIONS

Our study investigated MGMT status in a large series of lung carcinoids in the attempt to move forward a rational use of alkylating agents in these tumors. Interestingly, low MGMT gene expression defines a subgroup of lung carcinoids with aggressive features.

99mTc-EDDA/HYNIC-TOC is a New Opportunity in Neuroendocrine Tumors of the Lung (and in other Malignant and Benign Pulmonary Diseases)

Neuroendocrine tumors (NETs) consist of a relatively rare spectrum of malignancies that can arise from neuroendocrine cells; lung NETs (L-NETs) represent about 25% of primary lung neoplasm and 10% of all carcinoid tumors. Diagnostic algorithm usually takes into consideration chest Xray, contrast-enhanced CT and MRI. Nuclear medicine plays a crucial role in the detection and correct assessment of neoplastic functional status as it provides in vivo metabolic data related to the overexpression of Somatostatin Receptors (SSTRs) and also predicting response to peptide receptor radionuclide therapy (PRRT). 111In-Pentreotide (Octreoscan®) is commercially available for imaging of neuroendocrine tumors, their metastases and the management of patients with NETs. More recently, 99mTc-EDDA/HYNIC-TOC(Tektrotyd®) was introduced into the market and its use has been approved for imaging of patients with L-NETs and other SSTR-positive tumors. 99mTc-EDDA/HYNIC-TOC could also represent a good alternative to 68Ga-DOTA-peptides (DOTA-TOC, DOTA-NOC, DOTATATE) in hospitals or centers where PET/CT or 68Ge/68Ga generators are not available. When compared to 111In-Pentetreotide, Tektrotyd® showed slightly higher sensitivity, in the presence of higher imaging quality and lower radiation exposure for patients. Interesting perspectives depending on the kinetic analysis allowed by Tektrotyd® may be obtained in differential diagnosis of non-small cells lung cancer (NSCLC) versus small cells lung cancer (SCLC) and NETs. An interesting perspective could be also associated with a surgery radio-guided by Tektrotyd® in operable lung tumors, including either NETs and NSCLC.

Cancer stem-neuroendocrine cells in an atypical carcinoid case report

Lung neuroendocrine cells tumor (NET) classification and diagnosis, particularly for typical and atypical carcinoids, are complicated by a variable natural history and nonspecific symptoms. Mechanisms for the development and progression of well-differentiated lung NETs are still unclear. An accurate and timely diagnosis can ensure the implementation of appropriate treatment and impact on prognosis. One of the main unclear point is the definition of these cells' composition. In fact, it is known that carcinoids are mainly constituted by neuroendocrine cells. Aim of our report is to show for the first time the presence of a high percentage of cancer stem cells (CSCs) in an atypical carcinoid. The ALDEFLUOR assay was used to identify and sort ALDHhigh and ALDHlow human lung cancer cells following tissue digestion. SOX2 was additionally determined by immunohistochemistry. All specimens contained the 53.10% of ALDHhigh cells among all viable lung cancer cells, which indicates that more than half of the entire tumor cell population was composed by CSCs. As expected also in immunohistochemistry, about a half of the nuclei of the cells were positive for SOX2. We strongly support the hypothesis of the presence of cancer stem-neuroendocrine cells (CSCs-NETs) as subpopulation in these types of tumors.

Treatment of atypical pulmonary carcinoid with combination ipilimumab and nivolumab

Atypical pulmonary carcinoid (APC) is a lung neuroendocrine neoplasm (NEN), whose treatment draws from management of gastrointestinal NENs and small-cell lung carcinoma. We present a patient with recurrent metastatic APC and persistent mediastinal lymphadenopathy refractory to cisplatin and etoposide. After pursuing alternative treatments, he returned with significant progression, including diffuse subcutaneous nodules, weight loss and worsening cough. New biopsy analysis demonstrated APC with low mutational burden, low Ki-67 and Programmed Death-Ligand 1 (PD-L1), and without microsatellite instability. We pursued combination nivolumab and ipilimumab treatment based on success of CheckMate 032 in small-cell lung cancer. The patient's symptoms dramatically responded within a month, with almost complete resolution of lymphadenopathy following four cycles. He has been successfully maintained on nivolumab for the last 18 months. This suggests combination immunotherapy may be beneficial in the treatment of metastatic APC, and that PD-L1 and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) inhibitors may be valuable in treating tumours lacking traditional biomarkers.