Tumor/stromal caveolin-1 expression patterns in pleural mesothelioma define a subgroup of the epithelial histotype with poorer prognosis

OBJECTIVES

Malignant pleural mesothelioma (MPM) is a highly aggressive disease for which new prognostic biomarkers need to be identified. Caveolin-1 (CAV1), the most important member of caveolae, has been described as deregulated in MPM at the genomic level, but detailed histologic information on its distribution and prognostic role is still lacking.

METHODS

A series of 131 MPMs (91 epithelial, 17 biphasic, and 23 sarcomatous histotype) were investigated for CAV1 expression with immunohistochemistry and correlated with clinical-pathologic variables and outcome.

RESULTS

CAV1 was detected in neoplastic cells of 70 (77%) of 91 epithelial, 17 (100%) of 17 biphasic, and 23 (100%) of 23 sarcomatous MPMs. Furthermore, in the epithelial group, CAV1 expression in spindle-shaped stromal cells was detected in 61 (67%) of 91 cases.

CONCLUSIONS

The presence of stromal CAV1 expression was associated with a worse patient outcome. In MPM, CAV1 is differentially expressed according to low- to high-grade histotypes. Furthermore, in the MPM epithelial group, additional stromal CAV1 expression is associated with a worse prognosis.

Impact of pregnancy on prognosis of differentiated thyroid cancer: clinical and molecular features

OBJECTIVE

Differentiated thyroid cancer (DTC) commonly occurs in women of child-bearing age and represents the second most frequent tumor diagnosed during pregnancy only behind breast cancer. It is possible that associated physiological changes could favor tumor development and growth. However, few data are available about the outcome of DTC related to pregnancy, leading to conflicting results.

METHODS

Among the study population, 340 patients with DTC <45 years old were retrospectively studied. Patients were divided into three groups according to the time of tumor diagnosis in respect of pregnancy. Group 1, diagnosis of DTC at least 2 years after delivery; group 2, diagnosis during pregnancy or within the second year after delivery; and group 3, nulliparous patients at the time of diagnosis. We evaluated clinical outcome and immunohistochemical expression of estrogen receptor α (ERα), ERβ, progesterone receptor, and aromatase. We also analyzed the gene expression of NIS (SLC5A5) and the prevalence of BRAF(V600E) mutations.

RESULTS

Persistence/recurrence of disease was significantly higher in group 2 patients than control groups (P=0.023). No significant differences were observed in other clinical parameters. Furthermore, no differences among the groups were recorded about ER pattern, NIS expression, and BRAF mutations.

CONCLUSIONS

Persistence/recurrence of DTC is significantly higher in pregnant patients, suggesting that pregnancy could really exert a negative prognostic role in patients with DTC. The underlying mechanisms are not yet clarified and further studies are required. Our results suggest that a more careful follow-up is needed when diagnosis of DTC occurs during pregnancy or shortly after.

Differential expression of HER2, STAT3, SOX2, IFI16 and cell cycle markers during HPV-related head and neck carcinogenesis

The aim of this study was to analyze protein and gene expression of HER2 in 224 head and neck precancerous and malignant lesions by immunohistochemistry and FISH analysis. In parallel, expression of pStat3, Sox2, IFI16 and p16, Ki67 was evaluated. Immunohistochemical analysis was assessed on formalin-fixed paraffin-embedded (FFPE) tissue specimens. A combined method for HPV detection consisting of p16 immunostaining and two PCR probes was applied. HER2 gene status was evaluated by FISH analysis. HPV DNA was detected in 24% of cases with predominant HPV16 genotype. HPV-positive lesions had higher HER2, pStat3 and within carcinoma group, and higher IFI16 expression compared to the HPV-negative group (Fig. 1A-B-C). A strong positive correlation between Sox2 and proliferative activity was observed, whereas IFI16 expression displayed a negative relationship with Sox2 and Ki67 activity. The most striking result was higher pStat3 expression in HPV-positive lesions and its strong positive correlation with IFI16 expression. The presence of HPV may induce upregulation of HER2/neu, pStat3 and IFI16. High levels and a strong positive correlation between pStat3 and IFI16 suggest their synergistic pro-apoptotic effects in HPV-positive lesions.

Bevacizumab plus octreotide and metronomic capecitabine in patients with metastatic well-to-moderately differentiated neuroendocrine tumors: the XELBEVOCT study

Background

We assessed the activity and toxicity of the XELBEVOCT regimen in patients with metastatic well-to-moderately differentiated neuroendocrine neoplasms (WMD-NEN). Ancillary studies evaluated hypertension, proteinuria, and vascular endothelial growth factor (VEGF) polymorphisms in predicting progression-free survival (PFS) and the predictive role of serum vitamin D in progression-free survival and proteinuria onset.

Methods

This prospective phase 2 study included 45 patients with WMD-NEN arising from various primary sites. The treatment regimen was octreotide long-acting release (LAR), 20 mg monthly, metronomic capecitabine, 2000 mg/daily, and intravenous bevacizumab, 5 mg/kg every 2 weeks, without interruption for 9 months. Bevacizumab was continued until disease progression.

Results

Partial response was obtained in 8 patients (17.8%, 95% confidence interval [CI], 6.4%-28.2%); tumor response was more frequent in pancreatic than in non-pancreatic malignancies. The median PFS was 14.9 months; median overall survival was not attained. Biochemical and symptomatic responses were observed in 52.9% and 82.3% of cases, respectively. The treatment was well tolerated. Grade 3 toxicities included hand and foot syndrome (11.1%), proteinuria (4.4%), and renal toxicity (2.2%). Proteinuria (all grades) was correlated with longer PFS (p = 0.017). There was an inverse relationship between proteinuria and vitamin D levels. VEGF polymorphisms were not associated with patient outcome.

Conclusion

The XELBEVOCT regimen is active and well tolerated in patients with metastatic WMD-NEN. Proteinuria correlated with hypovitaminosis D status and was the best predictive factor of treatment efficacy.

Trial registration

Trial registration number NCT01203306.

Pathology of the adrenal cortex: a reappraisal of the past 25 years focusing on adrenal cortical tumors

A reappraisal of the major advances in the diagnostic pathology of adrenal cortical lesions and tumors in the last 25 years is presented, with special reference to the definition of malignancy in primary adrenal cancer and its variants. Slightly more than 25 years ago, Weiss proposed his diagnostic scoring system for adrenal cortical carcinoma. This represented a milestone for adrenal pathologists and the starting point for further modifications of the system, either through minor changes in the scoring procedure itself or concentrating on some particular Weiss criterion such as mitotic index, integrated into alternative scoring schemes or algorithms that are currently under validation. Improvements in diagnostic immunohistochemistry have led to the identification of markers of cortical origin, such as Melan-A, alpha-inhibin, and SF-1 and of prognostic factors in carcinoma, such as the Ki-67 proliferation index and SF-1 itself. With regard to hyperplastic conditions, genetic investigations have allowed the association of the majority of cases of primary pigmented nodular adrenocortical disease (PPNAD) in Carney complex to mutations in the gene encoding the regulatory subunit 1A of protein kinase A (PRKAR1A). Other hereditary conditions are also associated with adrenal cortical tumors, including the Li-Fraumeni, Beckwith-Wiedemann, Gardner, multiple endocrine neoplasia type 1, and neurofibromatosis type 1 syndromes. Moreover, several advances have been made in the knowledge of the molecular background of sporadic tumors, and a number of molecules/genes are of particular interest as potential diagnostic and prognostic biomarkers.

PI3KCA mutation status is of limited prognostic relevance in ER-positive breast cancer patients treated with hormone therapy

PI3K/AKT/mTOR pathway alterations are frequent in patients with infiltrating breast cancer (IBC). Their clinical and pathological relevance has been insufficiently documented. We evaluated PI3KCA for mutations and the expression of PTEN, AKT, mTOR and p70S6K by immunohistochemistry in 246 IBC patients treated with hormone therapy (median follow-up, 97 months). A PI3KCA mutation was observed in 50 out of 229 informative cases (21.8 %), PTEN loss in 107 out of 210 (51 %), moderate/high level of expression of AKT in 133 out of 188 (71 %), moderate/high level of expression of mTOR in 173 out of 218 (79 %) and moderate/high level of expression of p70S6K in 111 out of 192 cases (58 %). PI3KCA mutation was associated with the absence of Her2/neu amplification/overexpression and a low level of MIB1/Ki-67 labelling. The expression of p70S6K was associated with a high level of mTOR immunoreactivity, and high PTEN expression was associated with high AKT expression level. Univariate analysis showed that PI3KCA mutation status was not associated with clinical outcome in the series as a whole or in the node-negative subgroup. However, in the node-positive subgroup, exon 9 PI3KCA mutation was associated with unfavourable overall survival (OS), although its impact on the final model in multivariate analysis seemed to be limited. Of the other markers, only high p70S6K expression was associated with a significantly prolonged OS. PI3KCA mutation status is of limited prognostic relevance in oestrogen receptor-positive breast cancer patients treated with hormone therapy.

Grading the neuroendocrine tumors of the lung: an evidence-based proposal

Lung neuroendocrine tumors are catalogued in four categories by the World Health Organization (WHO 2004) classification. Its reproducibility and prognostic efficacy was disputed. The WHO 2010 classification of digestive neuroendocrine neoplasms is based on Ki67 proliferation assessment and proved prognostically effective. This study aims at comparing these two classifications and at defining a prognostic grading system for lung neuroendocrine tumors. The study included 399 patients who underwent surgery and with at least 1 year follow-up between 1989 and 2011. Data on 21 variables were collected, and performance of grading systems and their components was compared by Cox regression and multivariable analyses. All statistical tests were two-sided. At Cox analysis, WHO 2004 stratified patients into three major groups with statistically significant survival difference (typical carcinoid vs atypical carcinoid (AC), P=0.021; AC vs large-cell/small-cell lung neuroendocrine carcinomas, P<0.001). Optimal discrimination in three groups was observed by Ki67% (Ki67% cutoffs: G1 <4, G2 4-<25, G3 ≥25; G1 vs G2, P=0.021; and G2 vs G3, P≤0.001), mitotic count (G1 ≤2, G2 >2-47, G3 >47; G1 vs G2, P≤0.001; and G2 vs G3, P≤0.001), and presence of necrosis (G1 absent, G2 <10% of sample, G3 >10% of sample; G1 vs G2, P≤0.001; and G2 vs G3, P≤0.001) at uni and multivariable analyses. The combination of these three variables resulted in a simple and effective grading system. A three-tiers grading system based on Ki67 index, mitotic count, and necrosis with cutoffs specifically generated for lung neuroendocrine tumors is prognostically effective and accurate.

MEN1 gene mutation and reduced expression are associated with poor prognosis in pulmonary carcinoids

CONTEXT

MEN1 gene alterations have been implicated in lung carcinoids, but their effect on gene expression and disease outcome is unknown.

OBJECTIVE

Our objective was to analyze MEN1 gene and expression anomalies in lung neuroendocrine neoplasms and their correlations with clinicopathologic data and disease outcome.

DESIGN

We examined 74 lung neuroendocrine neoplasms including 58 carcinoids and 16 high-grade neuroendocrine carcinomas (HGNECs) for MEN1 mutations (n = 70) and allelic losses (n = 69), promoter hypermethylation (n = 65), and mRNA (n = 74) expression. Results were correlated with disease outcome.

RESULTS

MEN1 mutations were found in 7 of 55 (13%) carcinoids and in 1 HGNEC, mostly associated with loss of the second allele. MEN1 decreased expression levels correlated with the presence of mutations (P = .0060) and was also lower in HGNECs than carcinoids (P = .0024). MEN1 methylation was not associated with mRNA expression levels. Patients with carcinoids harboring MEN1 mutation and loss had shorter overall survival (P = .039 and P = .035, respectively) and low MEN1 mRNA levels correlated with distant metastasis (P = .00010) and shorter survival (P = .0071). In multivariate analysis, stage and MEN1 allelic loss were independent predictors of prognosis.

CONCLUSION

Thirteen percent of pulmonary carcinoids harbor MEN1 mutation associated with reduced mRNA expression and poor prognosis. Also in mutation-negative tumors, low MEN1 gene expression correlates with an adverse disease outcome. Hypermethylation was excluded as the underlying mechanism.

Cytotoxic activity of gemcitabine, alone or in combination with mitotane, in adrenocortical carcinoma cell lines

We aimed at investigating in vitro the cytotoxic activity (determined using WST-1, apoptosis and cell cycle assays) of gemcitabine, alone or in combination with mitotane, in mitotane-sensitive H295R and mitotane-insensitive SW-13 cells. Results of these experiments were compared with drug-induced modulation of RRM1 gene, the specific target of gemcitabine. In H295R cells, mitotane and gemcitabine combinations showed antagonistic effects and interfered with the gemcitabine-mediated inhibition of the S phase of the cell cycle. By contrast, in SW-13 cells, except when mitotane was sequentially administered prior to gemcitabine, the combination of the two drugs was synergistic. Such opposite effects were associated with opposite expression profiles of the target gene, with significant up-modulation in H295R but not in SW-13 under gemcitabine and mitotane combination treatment.

Mixed adenoneuroendocrine carcinomas of the gastrointestinal tract: targeted next-generation sequencing suggests a monoclonal origin of the two components

BACKGROUND

Mixed adenoneuroendocrine carcinomas (MANECs) of the gastrointestinal tract are rare neoplasms characterized by coexisting exocrine and neuroendocrine neoplastic components. MANECs' histogenetic classification and molecular characterization remain unclear, significantly affecting the identification of innovative therapeutic options for these tumors.

METHODS

The exocrine and neuroendocrine components of 6 gastrointestinal MANECs were microdissected and subjected to the simultaneous mutation assessment in selected regions of 54 cancer-associated genes using Ion Torrent semiconductor-based next-generation sequencing. Sanger sequencing and immunohistochemistry were used as validation of the mutational status.

RESULTS

A total of 20 driver gene somatic mutations were observed among the 12 neoplastic components investigated. In 11 of 12 (91.7%) samples, at least one mutation was detected; 7 samples (58.3%) were found to have multiple mutations. TP53 gene mutations were the most frequent genetic alterations observed in the series, occurring in 11/12 samples (91.7%). Somatic mutations in other genes were detected at lower frequencies: ATM, CTNNB1, ERBB4, JAK3, KDR, KRAS, RB1.

CONCLUSIONS

Five of the 6 MANECs presented an overlapping mutational profile in both components, suggesting a monoclonal origin of the two MANEC components.

CDC73 mutational status and loss of parafibromin in the outcome of parathyroid cancer

Inactivating mutations of the CDC73 tumor suppressor gene have been reported in parathyroid carcinomas (PC), in association with the loss of nuclear expression of the encoded protein, parafibromin. The aim of this study was to further investigate the role of the CDC73 gene in PC and evaluate whether gene carrier status and/or the loss of parafibromin staining might have an effect on the outcome of the disease. We performed genetic and immunohistochemical studies in parathyroid tumor samples from 35 patients with sporadic PC. Nonsense or frameshift CDC73 mutations were detected in 13 samples suitable for DNA sequencing. Six of these mutations were germline. Loss of parafibromin expression was found in 17 samples. The presence of the CDC73 mutation as well as the loss of parafibromin predicted a high likelihood of subsequent recurrence and/or metastasis (92.3%, P=0.049 and 94.1%, P=0.0017 respectively), but only the latter was associated with a decreased overall 5- and 10-year survival rates (59%, P=0.107, and 23%, P=0.0026 respectively). The presence of both the CDC73 mutation and loss of parafibromin staining compared with their absence predicted a lower overall survival at 10- (18 vs 84%, P=0.016) but not at 5-year follow-up. In conclusion, loss of parafibromin staining, better than CDC73 mutation, predicts the clinical outcome and mortality rate. The added value of CDC73 mutational analysis is the possibility of identifying germline mutations, which will prompt the screening of other family members.

Mitotane levels predict the outcome of patients with adrenocortical carcinoma treated adjuvantly following radical resection

CONTEXT

Mitotane plasma concentrations ≥ 14 mg/l have been shown to predict tumor response and better survival in patients with advanced adrenocortical carcinoma (ACC). A correlation between mitotane concentrations and patient outcome has not been demonstrated in an adjuvant setting.

OBJECTIVE

To compare recurrence-free survival (RFS) in patients who reached and maintained mitotane concentrations ≥ 1 4 mg/l vs patients who did not.

DESIGN AND SETTING

Retrospective analysis at six referral European centers.

PATIENTS

Patients with ACC who were radically resected between 1995 and 2009 and were treated adjuvantly with mitotane targeting concentrations of 14-20 mg/l.

MAIN OUTCOME MEASURES

RFS (primary) and overall survival (secondary).

RESULTS

Of the 122 patients included, 63 patients (52%) reached and maintained during a median follow-up of 36 months the target mitotane concentrations (group 1) and 59 patients (48%) did not (group 2). ACC recurrence was observed in 22 patients of group 1 (35%) and 36 patients in group 2 (61%). In multivariable analysis, the maintenance of target mitotane concentrations was associated with a significantly prolonged RFS (hazard ratio (HR) of recurrence: 0.418, 0.22-0.79; P=0.007), while the risk of death was not significantly altered (HR: 0.59, 0.26-1.34; P=0.20). Grades 3-4 toxicity was observed in 11 patients (9%) and was managed with temporary mitotane discontinuation. None of the patients discontinued mitotane definitively for toxicity.

CONCLUSIONS

Mitotane concentrations ≥ 14 mg/l predict response to adjuvant treatment being associated with a prolonged RFS. A monitored adjuvant mitotane treatment may benefit patients after radical removal of ACC.

An exploration of pathways involved in lung carcinoid progression using gene expression profiling

Pulmonary carcinoids comprise a well-differentiated subset of neuroendocrine tumors usually associated with a favorable prognosis, but mechanisms underlying disease progression are poorly understood. In an explorative approach to identify pathways associated with progression, we compared gene expression profiles of tumors from five patients with a favorable and five with a poor disease outcome. Differentially expressed genes were validated using quantitative real-time PCR on 65 carcinoid tumors, in combination with survival analysis. One of the identified pathways was further examined using immunohistochemistry. As compared with other chromosomal locations, a significantly higher number of genes downregulated in carcinoids with a poor prognosis were located at chromosome 11q (P = 0.00017), a region known to be frequently lost in carcinoids. In addition, a number of upregulated genes were found involved in the mitotic spindle checkpoint, the chromosomal passenger complex (CPC), mitotic kinase CDC2 activity and the BRCA-Fanconi anemia pathway. At the individual gene level, BIRC5 (survivin), BUB1, CD44, IL20RA, KLK12 and OTP were independent predictors of patient outcome. For survivin, the number of positive nuclei was also related to poor prognosis within the group of carcinoids. Aurora B kinase and survivin, major components of the CPC, were particularly upregulated in high-grade carcinomas and may therefore comprise therapeutic targets for these tumors. To our knowledge, this is the first expression profiling study focusing specifically on pulmonary carcinoids and progression. We have identified novel pathways underlying malignant progression and validated several genes as being strong prognostic indicators, some of which could serve as putative therapeutic targets.

Human ASH-1 promotes neuroendocrine differentiation in androgen deprivation conditions and interferes with androgen responsiveness in prostate cancer cells

BACKGROUND

Neuroendocrine differentiation in prostate cancer is a dynamic process associated to the onset of hormone-refractory disease in vivo. The molecular mechanisms underlying this process are poorly recognized. Our study aimed at testing in vitro the role of hASH-1, a transcription factor implicated in neuroendocrine differentiation, in the onset of neuroendocrine phenotype in prostate cancer cells.

METHODS

Androgen sensitive LNCAP, androgen insensitive PC-3, and three immortalized prostate cancer cell lines were cultured in standard and androgen deprivation conditions. Expression of hASH-1 was modulated by either specific lentiviral transduction or shRNA interference. Inhibitors of WNT-11, a WNT family member associated to the development of neuroendocrine differentiation in prostate cancer, were also used. Cell viability was measured using the MTS method. Neuroendocrine phenotype was assessed by morphology, immunohistochemistry and real time PCR for several neuroendocrine markers.

RESULTS

hASH-1 was up-modulated by androgen deprivation in LNCaP cells and in androgen-sensitive immortalized prostate cancer cells, and associated with the onset of a neuroendocrine phenotype. Silencing of hASH-1 prevented neuroendocrine differentiation, as did also the selective interference with the WNT-11 pathway. Moreover, hASH-1 over-expression in LNCaP cells was sufficient to promote neuroendocrine differentiation and increased cell viability at basal and androgen-deprived growth conditions.

CONCLUSION

In summary, the present data support previous evidence that the acquisition of a neuroendocrine phenotype is linked to androgen responsiveness profiles and suggest a pivotal role of hASH-1 transcription factor, whose activity might be explored as a potential therapeutic target in prostate cancer, with special reference to hormone refractory disease.

Integrative analysis of SF-1 transcription factor dosage impact on genome-wide binding and gene expression regulation

Steroidogenic Factor-1 (SF-1) is a nuclear receptor that has a pivotal role in the development of adrenal glands and gonads and in the control of steroid hormone production, being also implicated in the pathogenesis of adrenocortical tumors. We have analyzed the mechanisms how SF-1 controls gene expression in adrenocortical cells and showed that it regulates different categories of genes according to its dosage. Significant correlations exist between the localization of SF-1-binding sites in chromatin under different dosage conditions and dosage-dependent regulation of gene expression. Our study revealed unexpected functional interactions between SF-1 and Neuron-Restrictive Silencer Factor/RE1-Silencing Transcription Factor (NRSF/REST), which was first characterized as a repressor of neuronal gene expression in non-neuronal tissues, in the regulation of gene expression in steroidogenic cells. When overexpressed, SF-1 reshapes the repertoire of NRSF/REST—regulated genes, relieving repression of key steroidogenic genes. These data show that NRSF/REST has a novel function in regulating gene expression in steroidogenic cells and suggest that it may have a broad role in regulating tissue-specific gene expression programs.

Characterization of neuroendocrine tumors of the pancreas by real-time quantitative polymerase chain reaction. A methodological approach

The aim of this study was to assess the suitability of using real-time quantitative PCR (RT-qPCR) to characterize neuroendocrine (NE) tumors of the pancreas. For a series of tumors, we evaluated several genes of interest, and the data were matched with the "classical" immunohistochemical (IHC) features. In 21 cases, we extracted RNA from formalin-fixed paraffin-embedded (FFPE) blocks, and in nine cases, we also extracted RNA from fresh-frozen tissue. The RT-qPCR procedure was performed using two sets of customized arrays. The test using the first set, covering 96 genes of interest, was focused on assessing the feasibility of the procedure, and the results were used to select 18 genes indicative of NE differentiation, clinical behavior, and therapeutic responsiveness for use in the second set of arrays. Threshold cycle (Ct) values were used to calculate the fold-changes in gene expression using the 2-∆∆Ct method. Statistical procedures were used to analyze the results, which were matched with the IHC and follow-up data. Material from fresh-frozen samples performed better in terms of the level of amplification, but acceptable and concordant results were also obtained from FFPE samples. In addition, high concordance was observed between the mRNA and protein expression levels of somatostatin receptor type 2A (R = 0.52, p = 0.016). Genes associated with NE differentiation, as well as the gastrin-releasing peptide receptor and O-6-methylguanine-DNA methyltransferase genes, were underexpressed, whereas angiogenesis-associated markers (CDH13 and SLIT2) were overexpressed in tissues with malignant behavior. The RT-qPCR procedure is practical and feasible in economic terms for the characterization of NE tumors of the pancreas and can complement morphological and IHC-based evaluations. Thus, the results of the RT-qPCR procedure might offer an objective basis for therapeutic choices.

Abstract 2380: Reduced CD44 and OTP gene expression are strong indicators of poor prognosis in pulmonary carcinoids

Purpose: Pulmonary carcinoids are well-differentiated neuroendocrine tumors showing usually a favorable prognosis. However, there is a risk for late recurrence and/or distant metastasis. Because histological classification in typical and atypical (AC) carcinoids is difficult and its reliability to predict disease outcome varies, we evaluated three genes as potential prognostic markers, i.e., OTP, CD44 and RET.

Methods: These genes were analyzed in 56 frozen carcinoids by quantitative RT-PCR. RET was further studied by methylation and mutation analysis. Immunohistochemistry for CD44 and OTP protein expression was performed on 292 carcinoids.

Results: Low mRNA expression levels of CD44 (p=1.3e-5) and OTP (p=0.012), and high levels of RET (p=0.0025), were strongly associated with a low 20-year survival of carcinoid patients. High RET expression was not related to promoter hypomethylation or gene mutations. A direct link between gene expression and protein levels was confirmed for CD44 and OTP, but not for RET. Within all carcinoids as well as ACs, absence of CD44 protein was significantly associated with low 20-year survival (p=8.6e-5 and p=0.00015, respectively). The absence of nuclear OTP followed by complete loss of expression was also significantly associated with unfavorable disease outcome in all carcinoids (p=2.9e-5). Multivariate analysis revealed that CD44 and OTP immunostaining combined with histopathology is the optimal indicator for patient outcome.

Conclusions: Our study indicates that CD44 and OTP are strong indicators of poor outcome. We therefore argue for implementation of these markers in routine diagnostics in addition to histopathology to improve subclassification of pulmonary carcinoids into prognostically relevant categories.

Citation Format: Dorian RA Swarts, Mieke Henfling, Leander van Neste, Robert J. van Suylen, Anne-Marie Dingemans, Winand NM Dinjens, Annick Haesevoets, Martina Rudelius, Erik Thunnissen, Marco Volante, Wim van Criekinge, Manon van Engeland, Frans CS Ramaekers, Ernst-Jan M. Speel. Reduced CD44 and OTP gene expression are strong indicators of poor prognosis in pulmonary carcinoids. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2380. doi:10.1158/1538-7445.AM2013-2380

Detection and characterization of classical and "uncommon" exon 19 Epidermal Growth Factor Receptor mutations in lung cancer by pyrosequencing

Background

The management of advanced stage non-small cell lung cancer is increasingly based on diagnostic and predictive analyses performed mostly on limited amounts of tumor tissue. The evaluation of Epidermal Growth Factor Receptor (EGFR) mutations have emerged as the strongest predictor of response to EGFR-tyrosine kinase inhibitors mainly in patients with adenocarcinoma. Several EGFR mutation detection techniques are available, having both sensitivity and specificity issues, being the Sanger sequencing technique the reference standard, with the limitation of a relatively high amount of mutated cells needed for the analysis.

Methods

A novel nucleotide dispensation order for pyrosequencing was established allowing the identification and characterization of EGFR mutation not definable with commercially and clinically approved kits, and validated in a consecutive series of 321 lung cancer patients (246 biopsies or cytology samples and 75 surgical specimens).

Results

61/321 (19%) mutated cases were detected, 17 (27.9%) in exon 21 and 44 (72.1%) in exon 19, these latter corresponding to 32/44 (72.7%) classical and 12/44 (27.3%) uncommon mutations. Furthermore, a novel, never reported, point mutation, was found, which determined a premature stop codon in the aminoacidic sequence that resulted in a truncated protein in the tyrosine kinase domain, thus impairing the inhibitory effect of specific therapy.

Conclusions

The novel dispensation order allows to detect and characterize both classical and uncommon EGFR mutations. Although several phase III studies in genotypically defined groups of patients are already available, further prospective studies assessing the role of uncommon EGFR mutations are warranted.

CD44 and OTP are strong prognostic markers for pulmonary carcinoids

PURPOSE

Pulmonary carcinoids are well-differentiated neuroendocrine tumors showing usually a favorable prognosis. However, there is a risk for late recurrence and/or distant metastasis. Because histologic classification in typical and atypical carcinoids is difficult and its reliability to predict disease outcome varies, we evaluated three genes as potential prognostic markers, that is, orthopedia homeobox (OTP), CD44, and rearranged during transfection (RET).

EXPERIMENTAL DESIGN

These genes were analyzed in 56 frozen carcinoids by quantitative real-time PCR (qRT-PCR). RET was further studied by methylation and mutation analysis. Immunohistochemistry for CD44 and OTP protein expression was conducted on 292 carcinoids.

RESULTS

Low mRNA expression levels of CD44 (P = 1.8e(-5)) and OTP (P = 0.00054), and high levels of RET (P = 0.025), were strongly associated with a low 20-year survival of carcinoid patients. High RET expression was not related to promoter hypomethylation or gene mutations. A direct link between gene expression and protein levels was confirmed for CD44 and OTP but not for RET. Within all carcinoids as well as atypical carcinoids, absence of CD44 protein was significantly associated with low 20-year survival (P = 0.00014 and 0.00013, respectively). The absence of nuclear OTP followed by complete loss of expression was also significantly associated with unfavorable disease outcome in all carcinoids (P = 5.2(-6)). Multivariate analyses revealed that age at diagnosis, histopathology, stage, and cytoplasmic OTP immunoreactivity were independent predictors of prognosis.

CONCLUSIONS

Our study indicates that CD44 and OTP are strong indicators of poor outcome. We therefore argue for implementation of these markers in routine diagnostics in addition to histopathology to improve subclassification of pulmonary carcinoids into prognostically relevant categories.

Achaete-scute homolog 1 as a marker of poorly differentiated neuroendocrine carcinomas of different sites: a validation study using immunohistochemistry and quantitative real-time polymerase chain reaction on 335 cases

Neuroendocrine carcinomas show overlapping morphological and immunohistochemical features independently of their site of origin, which makes identification of the primary location problematic when they are diagnosed as metastases of unknown origin. Neuroendocrine carcinomas are easily morphologically differentiated from neuroendocrine tumors in surgical material, although this distinction can be difficult when using small biopsy specimens. The diagnostic usefulness of different transcription factors as site-specific markers or as discriminating markers between neuroendocrine carcinomas and neuroendocrine tumors has been previously studied with sometimes contradictory results. In this respect, the role of achaete-scute homolog 1 has been poorly investigated, although some recent findings demonstrate its expression in neuroendocrine carcinomas. Using immunohistochemistry and quantitative real-time polymerase chain reaction, we investigated the expression of achaete-scute homolog 1 in 335 neuroendocrine neoplasms (194 neuroendocrine carcinomas and 141 neuroendocrine tumors) of different sites, to check its possible utility as diagnostic marker. High concordance between immunohistochemical and molecular findings was found. Achaete-scute homolog 1 expression was identified in 82% of lung neuroendocrine carcinomas and 70% of extrapulmonary neuroendocrine carcinomas. Achaete-scute homolog 1 was not detected in any gastroenteropancreatic neuroendocrine tumor and was found in only a minority of lung carcinoids. The diagnostic sensitivity and specificity of achaete-scute homolog 1 expression were 82.4% and 89.7% in distinguishing neuroendocrine carcinomas from neuroendocrine tumors of the lung, 40.6% and 100% to differentiate extrapulmonary neuroendocrine carcinomas from neuroendocrine tumors, and 82.4% and 59.4% in distinguishing lung from extrapulmonary neuroendocrine carcinomas. Our data suggest that achaete-scute homolog 1 is not a site-specific marker. However, achaete-scute homolog 1 may be proposed as a diagnostic marker of poor differentiation and may help to differentiate neuroendocrine carcinomas from neuroendocrine tumors in difficult cases.

Ghrelin and tumors

Since the original discovery of ghrelin and, subsequently, obestatin (the alternative product of the ghrelin gene), a major interest has been devoted to the investigation of their central and peripheral activities in physiological conditions as well as on their role in metabolic diseases. However, several studies with different methodological approaches variably identified ghrelin and obestatin synthesis and secretion in several neoplastic conditions, including neuroendocrine and non-neuroendocrine cancers of various sites. Moreover, in vitro studies showed the capability of ghrelin to modulate tumor cell functions such as cell proliferation, apoptosis and invasiveness, although with variable and even paradoxical effects in different cell models. Interestingly, in most studies, it was demonstrated that ghrelin exerts its pro- or antineoplastic properties by means of receptors other than GHSR1a, that still need to be identified. However, the possible usefulness of the modulation of the ghrelin/obestatin axis in neoplastic conditions using either synthetic agonists or antagonists, though interesting in perspective, is still far from clinical applicability, and probably more related to the regulation of specific metabolic pathways in tumor cells, including lipid and carbohydrate use, than to the specific modulation of cell proliferation.

Reproducibility of immunohistochemical scoring for epidermal growth factor receptor expression in non-small cell lung cancer: round robin test

CONTEXT

The addition of cetuximab to first-line chemotherapy substantially prolonged survival in patients with advanced non-small cell lung cancer whose tumors expressed high levels of epidermal growth factor receptor (EGFR; immunohistochemistry score of ≥200 on a scale of 0-300).

OBJECTIVE

To evaluate the interobserver reproducibility of this EGFR immunohistochemistry scoring system, based on both the tumor cell membrane staining intensity (graded 0-3+) and the percentage of cells staining at each intensity.

DESIGN

In parts 1 (initial feasibility study) and 2 of this 2-part round robin test, sections of different non-small cell lung cancer tissue microarrays were stained in a central reference laboratory. Following reference evaluation, EGFR expression in 30 selected tumor cores was characterized in serial sections by lung cancer pathology specialists. The reproducibility of scoring by different raters was assessed. Analysis of between-rater agreement was based on the allocation of EGFR immunohistochemistry scores into low- (<200) and high- (≥200) EGFR expression groups.

RESULTS

After discussion with raters of the issues impacting reproducibility identified in part 1 and following adjustment of processes, part 2 of the round robin test showed a high interobserver agreement in EGFR immunohistochemistry scoring, with an overall concordance rate of 90.9% and a mean κ coefficient of 0.812. Specimens with a reference EGFR immunohistochemistry score of lower than 200 and of 200 or higher showed mean concordance rates of 94.7% and 85.6%, respectively.

CONCLUSIONS

After appropriate training, assessing EGFR expression by this immunohistochemistry-based method allowed a highly reproducible allocation of non-small cell lung cancers into clinically relevant high- or low-EGFR expression groups.