Ploidy, proliferative activity, p53 and bcl-2 expression in bronchopulmonary carcinoids: relationship with prognosis

Ki-67 Labeling Index in Pulmonary Carcinoid Tumors: Comparison Between Small Biopsy and Resection Using Tumor Tracing and Hot Spot Methods

CONTEXT.—

Pulmonary carcinoids are classified as typical or atypical by assessing necrosis and mitoses, which usually cannot be adequately assessed on small biopsies. Ki-67 is not currently used to grade pulmonary carcinoids, but it may be helpful to determine preliminary grade in biopsies. However, the rate at which Ki-67 could underestimate or overestimate grade on small biopsies has not been well studied.

OBJECTIVE.—

To compare Ki-67 labeling obtained on small biopsies to subsequent resection.

DESIGN.—

Ki-67 was performed on paired biopsy and resection specimens from 55 patients. Slides were scanned using Aperio ScanScope. Labeling index was determined using automated hot spot and tumor tracing methods.

RESULTS.—

The study included 41 typical and 14 atypical carcinoids. Atypical carcinoids were larger and had more distant metastases. Death from disease occurred in 3 patients (all had atypical carcinoids). Median hot spot Ki-67 labeling index was greater in resection compared with biopsy by 0.7% (P = .02). Median tumor tracing Ki-67 was lower in resection compared with biopsy by 0.5% (P < .001). Receiver-operating characteristic analysis showed similar hot spot Ki-67 cutoffs to predict atypical histology (3.5% for biopsy, 3.6% for resection; area under the curve [AUC], 0.75 and 0.74, respectively). Different optimal cutoffs were needed for tracing method based on biopsy (2.1%; AUC, 0.75) compared with resection (1.0%; AUC, 0.67).

CONCLUSIONS.—

Hot spot Ki-67 tends to underestimate grade on small biopsies, whereas grade is overestimated by tumor tracing. Hot spot Ki-67 cutoff of 3.5% predicted atypical histology for both biopsy and resection. Different biopsy and resection cutoffs were necessary for tumor tracing, which would make clinical implementation more difficult.

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.

Limited role of Ki-67 proliferative index in predicting overall short-term survival in patients with typical and atypical pulmonary carcinoid tumors

Pulmonary carcinoid tumors are currently classified as typical or atypical based on the mitotic index (2 per 10 hpf) and/or the presence of necrosis. Following incorporation of the Ki-67 index into the classification of GI carcinoid tumors, our oncologists have also been requesting this test as part of the work-up of pulmonary carcinoid tumors although there are currently no established criteria for interpreting Ki-67 index in these neoplasms. We utilized the Ariol(®) SL50 Image Analyzer system to measure the Ki-67 index in 101 pulmonary carcinoid tumors (78 typical and 23 atypical) and then correlated the Ki-67 index and the histological diagnoses in univariate and multivariable analysis with overall survival. The mean Ki-67 indices for the typical carcinoids (3.7 s.d.± 4.0) and the atypical carcinoids (18.8 s.d.± 17.1) were significantly different (P<0.001) although the frequency distributions of Ki-67 indices in the two groups overlapped considerably. Receiver operating characteristic curve analysis showed that a Ki-67 index cutoff value of 5% provided the best fit for specificity and sensitivity in predicting overall survival. Histological diagnosis and the Ki-67 index cutoff of 5% were each independently strong predictors of survival (P<0.001 and P=0.003, respectively). When considered together in multivariable analysis, histological diagnosis was the stronger predictor of overall survival and a Ki-67 index cutoff of 5% did not provide additional significant predictive survival information within either the typical carcinoid or the atypical carcinoid patient group. A few typical carcinoid patients with Ki-67 indices of 5% appeared to have worse survival after 5 years than those with Ki-67 indices <5%, but the data set was insufficiently powered to further analyze this. These findings do not provide best evidence for the routine use of Ki-67 index to prognosticate overall short-term survival in patients with pulmonary carcinoid tumors.

Well-Differentiated Neuroendocrine Carcinomas: The Spectrum of Histologic Subtypes and Various Clinical Behaviors

The term "well-differentiated neuroendocrine carcinoma" was coined to describe a variety of demonstrably neuroendocrine tumors which were more aggressive (both with respect to their histologic appearance and their clinical course) than (typical) bronchial carcinoids but were also clearly distinguishable from small cell neuroendocrine carcinomas. This umbrella term encompasses a variety of tumors previously described by a variety of terms including "atypical" carcinoids, "malignant tumorlets," peripheral stage I small-cell carcinoma, as well as neoplasms described simply as "undifferentiated carcinoma" (prior to the recognition of their neuroendocrine properties). As such, this term is a broad term and is not simply synonymous with "atypical carcinoid." Over time, at least 3 subtypes have been identified based upon their histologic appearance and mitotic index, with correspondingly aggressive clinical courses.

Ki-67 expression and patients survival in lung cancer: systematic review of the literature with meta-analysis

Among new biological markers that could become useful prognostic factors for lung carcinoma, Ki-67 is a nuclear protein involved in cell proliferation regulation. Some studies have suggested an association between Ki-67 and poor survival in lung cancer patients. In order to clarify this point, we have performed a systematic review of the literature, using the methodology already described by our Group, the European Lung Cancer Working Party. In total, 37 studies, including 3983 patients, were found to be eligible. In total, 49% of the patients were considered as having a tumour positive for the expression of Ki-67 according to the authors cutoff. In all, 29 of the studies dealt with non-small-cell lung carcinoma (NSCLC), one with small-cell carcinoma (SCLC), two with carcinoid tumours and five with any histology. In terms of survival results, Ki-67 was a bad prognosis factor for survival in 15 studies while it was not in 22. As there was no statistical difference in quality scores between the significant and nonsignificant studies evaluable for the meta-analysis, we were allowed to aggregate the survival results. The combined hazard ratio for NSCLC, calculated using a random-effects model was 1.56 (95% CI: 1.30–1.87), showing a worse survival when Ki-67 expression is increased. In conclusion, our meta-analysis shows that the expression of Ki-67 is a factor of poor prognosis for survival in NSCLC.

Typical and Atypical Pulmonary Carcinoid Tumor Overdiagnosed as Small-Cell Carcinoma on Biopsy Specimens

Seven patients with typical or atypical pulmonary carcinoid tumors overdiagnosed as small-cell carcinoma on bronchoscopic biopsies are described. Bronchial biopsies from 9 consecutive small-cell lung carcinoma patients were used as control group for histologic and immunohistochemical studies (cytokeratins, chromogranin A, synaptophysin, Ki-67 [MIB-1], and TTF-1). The carcinoid tumors presented as either central or peripheral lesions composed of tumor cells with granular, sometimes coarse chromatin pattern, high levels of chromogranin A/synaptophysin immunoreactivity, and low (<20%) Ki-67 (MIB-1) labeling index. The tumor stroma contained thin-walled blood vessels. Small-cell carcinomas always showed central tumor location, finely dispersed nuclear chromatin, lower levels of chromogranin A/synaptophysin, and high (>50%) Ki-67 (MIB-1) labeling index. The stroma contained thick-walled blood vessels with glomeruloid configuration. Judging from this study, overdiagnosis of carcinoid tumor as small-cell carcinoma in small crushed bronchial biopsies remains a significant potential problem in a worldwide sample of hospital settings. Careful evaluation of hematoxylin and eosin sections remains the most important tool for the differential diagnosis, with evaluation of tumor cell proliferation by Ki-67 (MIB-1) labeling index emerging from our review as the most useful ancillary technique for the distinction.

p53, cellular proliferation, and apoptosis-related factors in thymic neuroendocrine tumors

Thymic neuroendocrine tumors are biologically aggressive neoplasms with extensive local invasion and high mortality. Although various markers of cellular proliferation and apoptosis have correlated with degrees of tumor differentiation in pulmonary neuroendocrine neoplasms, they have not been systematically studied in thymic neuroendocrine tumors. We immunostained 21 cases of thymic neuroendocrine tumors for p53, MIB-1, and the apoptosis-related markers Bcl-2, Bcl-x, and Bax. By histological classification the cases were low-grade (nine cases), intermediate-grade (eight cases), and high-grade (four cases) thymic neuroendocrine tumors. p53 was expressed in five cases: 1/9 low grade, 3/8 intermediate grade, and 2/4 high grade. The mean cellular proliferation (MIB-1) was 7.1% (range 2-12%) in low-grade thymic neuroendocrine tumors, 6.1% (range 2-15%) in intermediate-grade thymic neuroendocrine tumors, and 34.2% (range 2-80%) in high-grade thymic neuroendocrine tumors. Bcl-2 was expressed in 16 cases: 7/9 low grade, 5/8 intermediate grade, and 4/4 high grade. Bcl-x was expressed in 16 cases: 7/9 low grade, 6/8 intermediate grade, and 3/4 high grade. Bax was expressed in 13 cases: 5/9 low grade, 4/8 intermediate grade, and 4/4 high grade. The presence of mutant p53 in the tumor was associated with a statistically significant decreased mean survival (P<0.05). In contrast, either by positive or negative staining or by the score technique (staining intensity x percentage of cells staining), the presence of Bcl-x was associated with an increased mean survival (P<0.05). Finally, a Bcl-x : Bax ratio >or=1 was also associated with an increased mean survival, as compared to a Bcl-x : Bax ratio >or=1 (P<0.05). Our study shows that p53 expression and certain apoptosis markers correlate with survival. The expression of these markers may account for differences in biological behavior.

The diffuse endocrine system: from embryogenesis to carcinogenesis

In the present review we will summarise the current knowledge about the cells comprising the Diffuse Endocrine System (DES) in mammalian organs. We will describe the morphological, histochemical and functional traits of these cells in three major systems gastrointestinal, respiratory and prostatic. We will also focus on some aspects of their ontogeny and differentiation, as well as to their relevance in carcinogenesis, especially in neuroendocrine tumors. The first chapter describes the characteristics of DES cells and some of their specific biological and biochemical traits. The second chapter deals with DES in the gastrointestinal organs, with special reference to the new data on the differentiation mechanisms that leads to the appearance of endocrine cells from an undifferentiated stem cell. The third chapter is devoted to DES of the respiratory system and some aspects of its biological role, both, during development and adulthood. Neuroendocrine hyperplasia and neuroendocrine lung tumors are also addressed. Finally, the last chapter deals with the prostatic DES, discussing its probable functional role and its relevance in hormone-resistant prostatic carcinomas.

Independent value of fascin immunoreactivity for predicting lymph node metastases in typical and atypical pulmonary carcinoids

Immunoreactivity for fascin, an actin-bundling protein related to cell motility, has been reported in breast, ovary, pancreas, skin, and non-small cell carcinomas, and associated with more advanced disease stage and poorer prognosis. Data on pulmonary neuroendocrine (NE) tumors, however, are lacking. We evaluated the expression of fascin by immunohistochemistry--using two different monoclonal antibodies--in surgical specimens of pulmonary NE tumors of all the diverse histological types from 128 consecutive patients recruited between 1987 and 2001, and investigated its relationship with the presence of lymph node metastases. Overall, fascin immunoreactivity was detected in 5% of 38 typical carcinoids (TC), 35% of 23 atypical carcinoids (AC), 83% of 40 large-cell neuroendocrine carcinomas (LCNEC), and 100% of 27 small-cell lung carcinomas (SCLC) (P<0.001), Normal NE cells or hyperplastic NE tumorlets were consistently unreactive. No statistically significant differences in fascin immunoreactivity were found between the two antibodies. In TC and AC but not high-grade NE tumors, fascin immunoreactivity closely correlated with the occurrence of lymph node metastases, the pN class and the number of involved lymph nodes (P<0.001). It was also significantly associated with an increased proliferative activity (Ki-67 labeling index >5%) (P=0.020), and with either down-regulation or altered subcellular compartmentalization of E-cadherin (P<0.001) and CD99 (P=0.030), two cell adhesion complexes in pulmonary NE tumors. At multivariate analysis, only fascin emerged as an independent predictor of lymph node metastases in this tumor group (HR 30.28; 95% confidence intervals: 1.59-574.49; P=0.023). This study indicates that fascin immunoreactivity may identify subsets of pulmonary carcinoid patients with different metastatic potential to regional lymph nodes. Targeting the fascin pathway could be a novel therapeutic strategy of pulmonary carcinoids.

Role of Bcl-2 as a prognostic factor for survival in lung cancer: a systematic review of the literature with meta-analysis

The role of the anti-apoptotic protein Bcl-2 in lung cancer remains controversial. In order to clarify its impact on survival in small and non-small cell lung cancer (NSCLC), we performed a systematic review of the literature. Trials were selected for further analysis if they provided an independent assessment of Bcl-2 in lung cancer and reported analysis of survival data according to Bcl-2 status. To make it possible to aggregate survival results of the published studies, their methodology was assessed using a quality scale designed by the European Lung Cancer Working Party (including study design, laboratory methods and analysis). Of 28 studies, 11 identified Bcl-2 expression as a favourable prognostic factor and three linked it with poor prognosis; 14 trials were not significant. No differences in scoring measurement were detected between the studies, except that significantly higher scores were found in the trials with the largest sample sizes. Assessments of methodology and of laboratory technique were made independently of the conclusion of the trials. A total of 25 trials, comprising 3370 patients, provided sufficient information for the meta-analysis. The studies were categorised according to histology, disease stage and laboratory technique. The combined hazard ratio (HR) suggested that a positive Bcl-2 status has a favourable impact on survival: 0.70 (95% confidence interval 0.57-0.86) in seven studies on stages I-II NSCLC; 0.50 (0.39-0.65) in eight studies on surgically resected NSCLC; 0.91 (0.76-1.10) in six studies on any stage NSCLC; 0.57 (0.41-0.78) in five studies on squamous cell cancer; 0.75 (0.61-0.93) and 0.71 (0.61-0.83) respectively for five studies detecting Bcl-2 by immunohistochemistry with Ab clone 100 and for 13 studies assessing Bcl-2 with Ab clone 124; 0.92 (0.73-1.16) for four studies on small cell lung cancer; 1.26 (0.58-2.72) for three studies on neuroendocrine tumours. In NSCLC, Bcl-2 expression was associated with a better prognosis. The data on Bcl-2 expression in small cell lung cancer were insufficient to assess its prognostic value.

Classification of low-grade neuroendocrine tumors of midgut and unknown origin

Metastasized neuroendocrine tumors of the gastrointestinal tract and of unknown origin show a highly variable clinical course. Within this group, low-grade and high-grade malignant tumors can be recognized based on the revised classification of neuroendocrine tumors of the lung, pancreas, and gut published by Capella et al in 1995. The present study investigated whether fine-tuning the prediction of prognosis was possible by dividing the group of low-grade malignant tumors of the midgut and of unknown origin into typical and atypical carcinoids by grading them according to the World Health Organization (WHO) classification criteria for neuroendocrine tumors of the lung. Moreover, the prognostic value of immunohistochemical stainings and clinical parameters was evaluated. The study group comprised patients diagnosed between 1983 and 1999 with liver metastases of a neuroendocrine tumor of the midgut n = 40) or of unknown origin (n = 16). As a control for the consistency of grading, 10 patients with metastasized neuroendocrine tumors of the lung also were evaluated. Immunohistochemical stainings for chromogranin A, synaptophysin, Leu 7/CD57, neural cell adhesion molecule/CD56, cytokeratin 8, bcl-2, p53, ki67, and HER2/neu were performed. The clinical parameters age, gender, urinary 5-HIAA level, and presence or absence of the carcinoid syndrome were evaluated. Tumors of the midgut and of unknown origin were evaluated together, because they were clinically similar. In this group of 56 patients, both the Capella and the WHO classification systems recognized the high-grade malignant tumors with a bad prognosis. When the low-grade malignant tumors (Capella) were divided into typical and atypical carcinoids (WHO), no difference in survival was observed, but when the dichotomy into typical and atypical was based on mitotic count alone, the difference became borderline significant (P =.072). Of the immunohistochemical stainings used, synaptophysin, cytokeratin 8, and ki67 had limited prognostic value. Age above 60 was the only clinical parameter of unfavorable prognostic significance. We conclude that high-grade malignant neuroendocrine tumors of the midgut and of unknown origin are recognized by both the Capella classification and the WHO classification of neuroendocrine tumors of the lung. Further subdividing low-grade malignant tumors at this location appears to be of less value than in the lung, but assessing the mitotic activity of these tumors might be of prognostic value.

Expression of p53 protein and tumor angiogenesis as prognostic factors in nasopharyngeal carcinoma patients

The objective of this study was to evaluate the possible prognostic significance of p53 protein overexpression and tumor angiogenesis (TA) in nasopharyngeal carcinoma (NPC) patients, together with other clinicopathological variables. Forty-two NPC patients were evaluated in relation to survival. Nuclear p53 overexpression in neoplastic and endothelial cells was detected by immunohistochemistry (IHC) with the monoclonal antibody DO-7 and the polyclonal antibody against factor VIII-related antigen, respectively. Thereafter, we evaluated p53 cases in order to determine their nuclear immunoreactivity from negative (-) to positive (+, ++, +++). In addition, microvessels were counted in the most active areas of tumor neovascularization or hotspots using an image computer analyzer (MicroImage). A Cox multiple regression survival analysis was used to determine the best prognostic indicators in NPC patients. As a result, tumor microvessel count, considered as a continuous variable, was the most important independent prognostic indicator in relation to survival (p = 0.0273), with a relative risk of death of 2,4399 [95% confidence interval = 1.1051 ; 5.3871] associated with the highest microvessel counts. Moreover, the only clinicopathological variable that demonstrated prognostic value in a Cox multiple regression survival analysis was histological type (p = 0.05). In addition, we did not observe any statistical association between intratumoral microvessel density (IMD), clinicopathological variables and p53 protein expression.

Neuroendocrine tumors of the bronchopulmonary tract: a reappraisal of their classification after 20 years

This article is an overview of the classification of pulmonary neuroendocrine neoplasms, their presentation, their pathologic appearance, and their clinical management. In addition, the original classification, based on histologic features, is reassessed in the light of newer areas in study, including neurosecretory products, neuroendocrine markers, ultrastructural studies, ploidy analysis, cell adhesion markers, apoptosis, oncogene mutation analysis, and genetic alterations. The histologic classification proposed in 1983 remains the single most valuable factor in establishing the diagnosis and, together with the TNM status, the prognosis of this group of interesting neoplasms.

Ki67 protein: the immaculate deception?

This article updates our previous review of Ki67 published in Histopathology 10 years ago. In this period the numbers of papers published featuring this antibody has increased 10-fold from 338 to 3489 indicating the considerable enthusiasm with which this antibody has been studied. This review attempts to provide an update on the characterization of the Ki67 protein, its function and its use as a prognostic or diagnostic tool.