Prognostic markers in patients with typical bronchial carcinoid tumors

Molecular challenges of neuroendocrine tumors

Neuroendocrine tumors (NETs) are a very heterogeneous group that are thought to originate from the cells of the endocrine and nervous systems. These tumors develop in a number of organs, predominantly in the gastrointestinal and pulmonary systems. Clinical detection and diagnosis are reliable at the late stages when metastatic spread has occurred. However, traditional conventional therapies such as radiation and chemotherapy are not effective. In the majority of cases even surgical resection at that stage is unlikely to produce promising reusults. NETs present a serious clinical challenge, as the survival rates remain low, and as these rare tumors are very difficult to study, novel approaches and therapies are required. This review will highlight the important points of accumulated knowledge covering the molecular aspects of the role of neuroendocrine cells, hormonal peptides, the reasons for ectopic hormone production in NET, neuropeptides and epigenetic regulation as well as the other challenging questions that require further understanding.

Atelectasis in pediatrics: a case of carcinoid tumor

Carcinoid pulmonary tumors occur in the fourth to sixth decades of life. Usually, typical carcinoid arise a decade earlier when compared to atypical carcinoid (45 years and 55 years, respectively). Typical carcinoid tumors are the most common primary lung neoplasm in children and late adolescents, but there are less than 40 cases described in the literature. The clinical presentation is nonspecific and usually the symptoms are due to bronchial obstruction, sometimes with recurrent pneumonia. Its rarity may delay diagnosis but in most cases a favorable course after treatment is observed. The authors describe the case of a 13-year-old girl diagnosed with a carcinoid tumor located on the intermediate bronchus. The treatment approach included endoscopic laser resection, for obstruction resolution, followed by a right inferior bilobectomy with mediastinal lymph node dissection as definitive treatment. Histopathology confirmed a typical carcinoid tumor with mediastinal ipsilateral lymph node involvement.

Classification of pulmonary neuroendocrine tumors: new insights

Neuroendocrine tumors of the lung (Lu-NETs) embrace a heterogeneous family of neoplasms classified into four histological variants, namely typical carcinoid (TC), atypical carcinoid (AC), large cell neuroendocrine carcinoma (LCNEC) and small cell lung carcinoma (SCLC). Defining criteria on resection specimens include mitotic count in 2 mm2 and the presence or absence of necrosis, alongside a constellation of cytological and histological traits including cell size and shape, nuclear features and overall architecture. Clinically, TC are low-grade malignant tumors, AC intermediate-grade malignant tumors and SCLC/LCNEC high-grade malignant full-blown carcinomas with no significant differences in survival between them. Homologous tumors arise in the thymus that occasionally have some difficulties in differentiating from the lung counterparts when presented with large unresectable or metastatic lesions. Immunohistochemistry (IHC) helps refine NE diagnosis at various anatomical sites, particularly on small-sized tissue material, in which only TC and small cell carcinoma categories can be recognized easily on hematoxylin & eosin stain, while AC and LCNEC can only be suggested on such material. The Ki-67 labeling index effectively separates carcinoids from small cell carcinoma and may prove useful for the clinical management of a metastatic disease to help the therapeutic decision-making process. Although carcinoids and high-grade neuroendocrine carcinomas in the lung and elsewhere make up separate tumor categories on molecular grounds, emerging data supports the concept of secondary high-grade NETs arising in the preexisting carcinoids, whose clinical and biological relevance will have to be placed into the proper context for the optimal management of these patients. In this review, we will discuss the selected, recent literature with a focus on current issues regarding Lu-NET nosology, i.e., classification, derivation and tumor evolution.

Ki-67 labeling index of neuroendocrine tumors of the lung has a high level of correspondence between biopsy samples and surgical specimens when strict counting guidelines are applied

Optimal histopathological analysis of biopsies from metastases of neuroendocrine tumor (NET) of the lung requires more than morphology only. Additional parameters such as Ki-67 labeling index are required for adequate diagnosis, but few studies have compared reproducibility of different counting protocols and modalities of reporting on biopsies of lung NET. We compared the results of four different manual counting techniques to establish Ki-67 LI. On 47 paired biopsies and surgical specimens from 22 typical carcinoids (TCs), 14 atypical carcinoids (ACs), six large cell neuroendocrine carcinomas (LCNECs), and five small cell carcinomas (SCCs) immunohistochemical staining of Ki-67 antigen was performed. We counted, in regions of highest nuclear staining (HSR), a full ×40-high-power field (diameter = 0.55 mm), 500 or 2000 cells, or 2 mm² surface area, including the HSR or the entire biopsy fragment(s). Mitoses and necrosis were evaluated in an area of 2 mm² or the entire biopsy fragment(s). Between the four counting methods, no differences in Ki-67 LI were observed. However, a Ki-67 LI higher than 5% was found in only four cases when in an HSR, 500 cells were counted (18%), five (23%) when in an HSR 2000 cells were counted, four (18%) when 2 mm² were counted, and one (5%) TC case when the entire biopsy was counted. A 20% cutoff distinguished TC and AC from LCNEC and SCC with 100% specificity and sensitivity, while mitoses and necrosis failed to a large extent. Ki-67 LI in biopsy samples was concordant with that in resection specimens when 2000 cells, 2 mm², or the entire biopsy fragment(s) were counted. Our results are important for clinical management of patients with metastases of a lung NET.

Evaluation of diagnostic and prognostic significance of Ki-67 index in pulmonary carcinoid tumours

BACKGROUND

Pulmonary carcinoid (PC) tumours are classified as either typical (TC) or atypical (AC) according to mitotic index (MI) and presence of necrosis. The aim of this study was to analyse the diagnostic and prognostic values of the Ki-67 index in PC.

METHODS/PATIENTS

Between January 2001 and March 2015, we evaluated 94 consecutive patients with a confirmed diagnosis of TC (n = 75) or AC (n = 19) at our institution. Diagnostic histology was centrally reviewed by a local expert neuroendocrine pathologist, with assessment of Ki-67, MI, and necrosis.

RESULTS

Median patient follow-up was 35 months. Eighty-four patients who underwent curative surgical resection were included in the survival analysis for identification of prognostic factors. Ki-67 index showed high diagnostic accuracy to predict histological subtype when assessed by receiver operator characteristic curves with an area under the curve of 0.923 (95% CI 0.852-0.995, p < 0.001). Multivariate analysis showed that MI, Ki-67 index, and the presence or absence of necrosis were independent prognostic factors for relapse-free survival. Combination of MI, Ki-67, and necrosis led to the classification of patients into four different prognostic groups (very low, low, intermediate, and high risks of relapse).

CONCLUSIONS

The current study proposes the incorporation of Ki-67 index in the prognostic classification of PC tumours. Due to the limited number of patients and length of follow-up, the current model needs validation by larger cohort studies. Nevertheless, our results suggest that Ki-67 index and MI have continuous effect on prognosis. Prognostic models incorporating multiple cutoffs of Ki-67 and MI might better predict outcome and inform clinical decisions.

Usefulness of Ki-67, Mitoses, and Tumor Size for Predicting Metastasis in Carcinoid Tumors of the Lung: A Study of 48 Cases at a Tertiary Care Centre in Canada

Background. Evaluation of Ki-67 index in lung carcinoid tumors (LCTs) has been of interest in order to identify high risk subsets. Our objectives are (1) to evaluate the usefulness of Ki-67 index, mitoses, and tumor size in predicting metastasis and (2) to compare the Manual Conventional Method (MCM) and the Computer Assisted Image Analysis Method (CIAM) for Ki-67 calculation. Methods. We studied 48 patients with LCTs from two academic centres in Canada. For Ki-67 calculation, digital images of 5000 cells were counted using an image processing software and 2000 cells by MCM. Mitoses/10 HPF was counted. Results. We had 37 typical carcinoids (TCs) and 11 atypical carcinoids (ACs). 7/48 patients developed metastasis. There was a positive relationship between metastasis and carcinoid type (P = 0.039) and metastasis and mitoses (≥2) (P = 0.017). Although not statistically significant, the mean Ki-67 index for ACs was higher than for TCs (0.95% versus 0.72%, CIAM, P = 0.299). Similarly, although not statistically significant, the mean Ki-67 index for metastatic group (MG) was higher than for nonmetastatic group (NMG) (1.01% versus 0.71% by CIAM, P = 0.281). However when Ki-67 index data was categorized at various levels, there is suggestion of a useful cutoff (≥0.50%) to predict metastasis (P = 0.106, CIAM). A significantly higher proportion of patients with mitosis ≥2 and Ki-67 index ≥0.50% had metastasis (P = 0.033) compared to other patients. Similarly patients with tumor size ≥3 cm and Ki-67 ≥0.50% had a greater percentage of metastases than others (P = 0.039). Although there was a strong correlation between two (MCM versus CIAM) counting methods (r = 0.929, P = 0.001), overall the calculated Ki-67 index was slightly higher by MCM (range 0 to 6.4, mean 1.5) compared to CIAM (range 0 to 2.9, mean 0.75). Conclusion. This study confirms that mitoses ≥2 is a powerful predictor of metastasis in LCTs. Although this is a small sample size, there is suggestion that analysis of Ki-67 index along with mitoses and tumor size may be a useful adjunct for predicting metastasis in LCTs.

Unraveling tumor grading and genomic landscape in lung neuroendocrine tumors

Currently, grading in lung neuroendocrine tumors (NETs) is inherently defined by the histological classification based on cell features, mitosis count, and necrosis, for which typical carcinoids (TC) are low-grade malignant tumors with long life expectation, atypical carcinoids (AC) intermediate-grade malignant tumors with more aggressive clinical behavior, and large cell NE carcinomas (LCNEC) and small cell lung carcinomas (SCLC) high-grade malignant tumors with dismal prognosis. While Ki-67 antigen labeling index, highlighting the proportion of proliferating tumor cells, has largely been used in digestive NETs for assessing prognosis and assisting therapy decisions, the same marker does not play an established role in the diagnosis, grading, and prognosis of lung NETs. Next generation sequencing techniques (NGS), thanks to their astonishing ability to process in a shorter timeframe up to billions of DNA strands, are radically revolutionizing our approach to diagnosis and therapy of tumors, including lung cancer. When applied to single genes, panels of genes, exome, or the whole genome by using either frozen or paraffin tissues, NGS techniques increase our understanding of cancer, thus realizing the bases of precision medicine. Data are emerging that TC and AC are mainly altered in chromatin remodeling genes, whereas LCNEC and SCLC are also mutated in cell cycle checkpoint and cell differentiation regulators. A common denominator to all lung NETs is a deregulation of cell proliferation, which represents a biological rationale for morphologic (mitoses and necrosis) and molecular (Ki-67 antigen) parameters to successfully serve as predictors of tumor behavior (i.e., identification of pathological entities with clinical correlation). It is envisaged that a novel grading system in lung NETs based on the combined assessment of mitoses, necrosis, and Ki-67 LI may offer a better stratification of prognostic classes, realizing a bridge between molecular alterations, morphological features, and clinical behavior.

Atypical or typical adrenocorticotropic hormone-producing pulmonary carcinoids and the usefulness of 11C-5-hydroxytryptophan positron emission tomography: two case reports

Introduction

Pulmonary carcinoids associated with ectopic adrenocorticotropic hormone secretion have a good prognosis if histological examination shows typical pulmonary carcinoid and low proliferation, whereas a poor outcome is linked to atypical pulmonary carcinoid and high proliferation. Here we describe the diagnostic challenges to find the tumor in Cushing’s syndrome secondary to ectopic adrenocorticotropic hormone secretion in two cases with an atypical and a typical pulmonary carcinoid, respectively.

Case presentation

A 63-year-old Caucasian woman presented with aggressive clinical features related to Cushing’s syndrome, having very high levels of urinary cortisol and circulating adrenocorticotropic hormone and cortisol. Magnetic resonance imaging showed no pituitary tumor, and bilateral inferior petrosal sinus sampling revealed no central peripheral ratio of adrenocorticotropic hormone. Computed tomography and ¹¹¹Indium-pentetreoide somatostatin receptor scintigraphy could not visualize any ectopic tumor. The patient was referred for an ¹¹C-5-hydroxytryptophan positron emission tomography, and a small 8mm nodule in her left lung was found. The tumor was removed via a lateral thoracic incision and wedge excision. The histological examination showed an atypical carcinoid with Ki-67 index of 9 to 10%, and an additional lobectomy was performed.

The second patient, a 22-year-old Caucasian man, also presented with aggressive Cushing’s syndrome, with very high urinary cortisol levels and increased circulating cortisol as well as adrenocorticotropic hormone levels. A magnetic resonance imaging scan of the pituitary showed no tumor, whereas a 12×9×14mm tumor was detected in the right lung on the primary computed tomography scan and no further investigation was performed. The tumor was removed via a lateral thoracic incision and wedge excision. A typical carcinoid with Ki-67 index of 1 to 2% was found and no further surgery was performed.

After surgical removal, the biochemical disturbances resolved and significant clinical improvement were achieved in both patients after 24 months of follow up.

Conclusions

Diagnostic evaluation time is limited due to the aggressive course in ectopic adrenocorticotropic hormone-dependent Cushing’s syndrome. We suggest that ¹¹C-5-hydroxytryptophan positron emission tomography could be considered early as a secondary diagnostic tool when primary computed tomography and/or magnetic resonance imaging scans fail to show any tumor.

Typical bronchial carcinoid metastasizing to the brain: a case presentation

INTRODUCTION

Typical bronchial carcinoid tumors are known for their relatively indolent behavior. There are only four reported cases in the medical literature describing typical bronchial carcinoids metastasizing to the brain. Little is known about the pathogenesis and presentation of this disease due to the very small patient population.

CASE PRESENTATION

A 67-year-old Hispanic female presented to our hospital with a three-week history of right arm numbness and poor coordination. Computed tomography (CT) with intravenous contrast of the brain and subsequent magnetic resonance imaging demonstrated multiple enhancing nodular densities throughout the brain. CT with intravenous contrast of the chest, abdomen, and pelvis revealed a left hilar mass and a medial left upper lobe mass. Histopathological findings were consistent with a neuroendocrine neoplasm of bronchial origin.

CONCLUSION

Although metastases to the central nervous system are very frequent with small cell carcinomas, their presence is very uncommon in well-differentiated neuroendocrine tumors such as the one we present here. This case raises questions about whether these tumors contain biomarkers that might predict a more aggressive behavior and if these patients might benefit from aggressive interventions similar to those taken in small cell carcinomas, such as prophylactic cranial radiation.

Deletions of 11q22.3-q25 are associated with atypical lung carcinoids and poor clinical outcome

Carcinoids are slow-growing neuroendocrine tumors that, in the lung, can be subclassified as typical (TC) or atypical (AC). To identify genetic alterations that improve the prediction of prognosis, we investigated 34 carcinoid tumors of the lung (18 TCs, 15 ACs, and 1 unclassified) by using array comparative genomic hybridization (array CGH) on 3700 genomic bacterial artificial chromosome arrays (resolution ≤1 Mb). When comparing ACs with TCs, the data revealed: i) a significant difference in the average number of chromosome arms altered (9.6 versus 4.2, respectively; P = 0.036), with one subgroup of five ACs having more than 15 chromosome arms altered; ii) chromosomal changes in 30% of ACs or more with additions at 9q (≥1 Mb) and losses at 1p, 2q, 10q, and 11q; and iii) 11q deletions in 8 of 15 ACs versus 1 of 18 TCs (P = 0.004), which was confirmed via fluorescence in situ hybridization. The four critical regions of interest in 45% ACs or more comprised 11q14.1, 11q22.1-q22.3, 11q22.3-q23.2, and 11q24.2-q25, all telomeric of MEN1 at 11q13. Results were correlated with patient clinical data and long-term follow-up. Thus, there is a strong association of 11q22.3-q25 loss with poorer prognosis, alone or in combination with absence of 9q34.11 alterations (P = 0.0022 and P = 0.00026, respectively).

Expression of p-AKT and p-mTOR in a large series of bronchopulmonary neuroendocrine tumors

Bronchopulmonary neuroendocrine tumors (BP-NETs) are separated into four subgroups: typical carcinoid tumor (TC), atypical carcinoid tumor (AC), large-cell neuroendocrine carcinoma (LCNEC) and small-cell lung carcinoma (SCLC). The signaling pathway involving AKT/mammalian target of rapamycin (mTOR) is crucial to the regulation of cell growth, proliferation and survival, and is frequently activated in human cancers. Consequently, mTOR is considered an attractive target for anticancer agents. The present study aimed to evaluate the expression of phosphorylated AKT and mTOR in a series of BP-NETs, and to analyze the correlations with clinicopathological parameters. p-AKT and p-mTOR levels were determined by immunohistochemistry in a series of 210 BP-NETs, including 85 SCLCs, 17 LCNECs, 26 ACs, 75 TCs and 7 tumorlets. Higher p-AKT and p-mTOR expression levels were identified in the majority of tumorlets and carcinoids in comparison to the LCNECs (P=0.0001) and SCLCs (P=0.0002). Furthermore, a significant association was observed between p-mTOR expression and tumor size (T) in SCLCs (P=0.04) and LCNECs (P=0.03): T3-T4 tumors exhibited significantly lower p-mTOR expression compared to T1-T2 tumors. In conclusion, most of the BP-NETs examined in this study expressed p-AKT and p-mTOR, suggesting that the AKT/mTOR pathway plays an important role in these tumors. Additionally, our results confirm that low- to intermediate-grade tumors are more closely associated to each other than to high-grade tumors, despite sharing common classification and a common origin from neuroendocrine cells. These findings improve our knowledge of the biological characterization of these tumors and indicate new therapeutic opportunities for the treatment of BP-NETs.

[Retrospective study of clinicopathological characteristics in bronchopulmonary carcinoid]

背景与目的

支气管肺类癌（bronchopulmonary carcinoid, BPC）占全部肺原发性恶性肿瘤不到2%，相关研究报道较少，本研究拟分析BPC的总体及其两个亚型——典型类癌（typical carcinoid, TC）和不典型类癌（atypical carcinoid, AC）的临床、病理学特点。

方法

回顾性分析中山大学肿瘤防治中心1994年1月-2009年6月收治的28例BPC的临床资料，调取可再行切片的病理蜡块，重新切片染色及病理玻片会诊，分析BPC的总体及其亚型的临床特征和相关免疫组化指标与预后的关系。

结果

全部28例患者的总体5年生存率为56%，TC的5年生存率为70%，AC为41%，单因素分析示TNM分期（P=0.037)、有无淋巴结转移（P=0.001）、Ki-67核阳性数是否大于5%（P=0.009）是BPC总体的预后因素。相关性分析示BPC亚型与CD99、Bcl-2及Ki-67的表达具有相关性（P值分别0.017、0.043、0.033）。20例行肺癌根治性手术患者的5年生存率为73%，TC的5年生存率为83%，AC为57%。单因素分析示BPC亚型（P=0.013）、术后有无淋巴结转移（P=0.004)、Ki-67核阳性数是否大于5%（P=0.006）、TNM分期（P=0.047）是行肺癌根治性手术患者的预后因素。肿瘤复发（n=4）与Ki-67核阳性的表达和Bcl-2表达具有相关性（P值分别为0.027、0.045）。

结论

BPC是预后较好的肺原发性恶性肿瘤，Ki-67、Bcl-2的高表达是提示BPC复发及预后不良的影响因素，TNM分期是影响预后的独立因素，行根治性手术是主要的治疗手段。

The influence of tobacco smoking on adhesion molecule profiles

Sequential interactions between several adhesion molecules and their ligands regulate lymphocyte circulation and leukocyte recruitment to inflammatory foci. Adhesion molecules are, therefore, central and critical components of the immune and inflammatory system. We review the evidence that tobacco smoking dysregulates specific components of the adhesion cascade, which may be a common factor in several smoking-induced diseases. Smoking causes inappropriate leukocyte activation, leukocyte-endothelial adhesion, and neutrophil entrapment in the microvasculature, which may help initiate local tissue destruction. Appropriate inflammatory reactions may thus be compromised. In addition to smoke-induced alterations to membrane bound endothelial and leukocyte adhesion molecule expression, which may help explain the above phenomena, smoking has a profound influence on circulating adhesion molecule profiles, most notably sICAM-1 and specific sCD44 variants. Elevated concentrations of soluble adhesion molecules may simply reflect ongoing inflammatory processes. However, increasing evidence suggests that specific soluble adhesion molecules are immunomodulatory, and that alterations to soluble adhesion molecule profiles may represent a significant risk factor for several diverse diseases. This evidence is discussed herein.