Neuroendocrine differentiation as a prognostic factor in non-small cell lung cancer

Role of Synaptophysin, Chromogranin and CD56 in adenocarcinoma and squamous cell carcinoma of the lung lacking morphological features of neuroendocrine differentiation: a retrospective large-scale study on 1170 tissue samples

BACKGROUND

Synaptophysin, chromogranin and CD56 are recommended markers to identify pulmonary tumors with neuroendocrine differentiation. Whether the expression of these markers in pulmonary adenocarcinoma and pulmonary squamous cell carcinoma is a prognostic factor has been a matter of debate. Therefore, we investigated retrospectively a large cohort to expand the data on the role of synaptophysin, chromogranin and CD56 in non-small cell lung cancer lacking morphological features of neuroendocrine differentiation.

METHODS

A cohort of 627 pulmonary adenocarcinomas (ADC) and 543 squamous cell carcinomas (SqCC) lacking morphological features of neuroendocrine differentiation was assembled and a tissue microarray was constructed. All cases were stained with synaptophysin, chromogranin and CD56. Positivity was defined as > 1% positive tumor cells. Data was correlated with clinico-pathological features including overall and disease free survival.

RESULTS

110 (18%) ADC and 80 (15%) SqCC were positive for either synaptophysin, chromogranin, CD56 or a combination. The most commonly positive single marker was synaptophysin. The least common positive marker was chromogranin. A combination of ≤2 neuroendocrine markers was positive in 2-3% of ADC and 0-1% of SqCC. There was no significant difference in overall survival in tumors with positivity for neuroendocrine markers neither in ADC (univariate: P = 0.4; hazard ratio [HR] = 0.867; multivariate: P = 0.5; HR = 0.876) nor in SqCC (univariate: P = 0.1; HR = 0.694; multivariate: P = 0.1, HR = 0.697). Likewise, there was no significant difference in disease free survival.

CONCLUSIONS

We report on a cohort of 1170 cases that synaptophysin, chromogranin and CD56 are commonly expressed in ADC and SqCC and that their expression has no impact on survival, supporting the current best practice guidelines.

LMO1 functions as an oncogene by regulating TTK expression and correlates with neuroendocrine differentiation of lung cancer

LMO1 encodes a protein containing a cysteine-rich LIM domain involved in protein-protein interactions. Recent studies have shown that LMO1 functions as an oncogene in several cancer types, including non-small cell lung cancer (NSCLC). However, the function of LMO1 in other histological subtypes of lung cancer, such as small cell lung cancer (SCLC), was not investigated. In analyzing the expression of LMO1 across a panel of lung cell lines, we found that LMO1 expression levels were significantly and dramatically higher in SCLC cells, an aggressive neuroendocrine subtype of lung cancer, relative to NSCLC and normal lung cells. In NSCLC cells, LMO1 mRNA levels were significantly correlated with expression of neuroendocrine differentiation markers. Our in vitro investigations indicated that LMO1 had the general property of promoting cell proliferation in lung cancer cells representing different histological subtypes, suggesting a general oncogenic function of LMO1 in lung cancer. In investigating the clinical relevance of LMO1 as an oncogene, we found that a high tumor level of the LMO1 mRNA was an independent predictor of poor patient survival. These results suggest that LMO1 acts as an oncogene, with expression correlated with neuroendocrine differentiation of lung cancer, and that it is a determinant of lung cancer aggressiveness and prognosis. By combining gene expression correlations with patient survival and functional in vitro investigations, we further identified TTK as mediating the oncogenic function of LMO1 in lung cancer cells.

Cytosolic Levels of Neuron-Specific Enolase in Squamous Cell Carcinomas of the Lung

To study the behavior and possible correlations of neuron-specific enolase (NSE) with other clinicobiological parameters, we measured the cytosolic levels of this marker by means of an immunoradiometric assay (IRMA) in 95 squamous cell lung carcinoma samples. We also analyzed the levels of pS2, tissue-type plasminogen activator (t-PA), hyaluronic acid (HA), free beta subunit of human chorionic gonadotropin (β-HCG), CYFRA 21.1 and CA 125 in cytosol. On the cell surface we analyzed the concentrations of epidermal growth factor receptor (EGFR), HA, erbB-2 oncoprotein, CD44s, CD44v5 and CD44v6. Other parameters considered were clinical stage, lymph node involvement, histological grade (HG), ploidy and the cellular S-phase fraction measured by flow cytometry on nuclei obtained from fresh tissues.

In the 95 squamous cell carcinomas the cytosolic levels of NSE varied from 4.5 to 2235 ng/mg protein (median: 267) and were significantly higher (p<0.001) than those observed in 38 samples of normal pulmonary tissue obtained from the same patients (range: 56–657; median: 141.5). When classifying tumors according to the different parameters analyzed, we observed that the levels of NSE were higher in aneuploid than in diploid cases (p=0.046) and in those that were HG3 than in those that were HG2 (p<0.001). Tumors with high NSE levels (>422 ng/mg protein; 75th percentile) were more likely to have high S-phase values (p=0.012) and were more frequently aneuploid (p=0.038) and HG3 (p<0.001) than those with low levels of NSE (<180 ng/mg protein; 25th percentile).

These results lead us to the following conclusions: 1) the cytosolic concentrations of NSE are significantly higher in squamous cell carcinomas than in healthy pulmonary tissue, and 2) the cytosolic concentrations of NSE are not correlated with clinical stage or nodal involvement. However, in our study higher levels of the enzyme were statistically correlated with aneuploidy, histological grade 3 and S-phase. This may explain its association with poorer outcome and progression, but also the more favorable response of tumors with elevated NSE to chemotherapy, as suggested by other groups.

Large cell carcinoma of lung: On the verge of extinction?

Pulmonary large cell carcinoma is a tumor whose existence as a defined entity has been challenged in recent years in the wake of advances in techniques to subtype lung cancer. Large cell carcinoma has been defined in the past as a tumor that lacks morphologic evidence of either glandular or squamous differentiation. This rather vague definition and the inclusion of more specific entities such as large cell neuroendocrine carcinoma, basaloid carcinoma, lymphoepithelioma-like carcinoma, clear cell carcinoma, and large cell carcinoma with rhabdoid phenotype as subtypes of large cell carcinoma has not only diluted the homogeneity of this entity but has also contributed to its use as a "wastebin" category for tumors lacking a definitive morphologic pattern. Today, there is increasing evidence that a large proportion of these tumors can be subtyped further using modern immunohistochemical and molecular methods. This is of special value not only from a diagnostic point of view but becomes increasingly important in terms of treatment choice since the selection of therapeutic modalities is often based on specific tumor histology. When viewed in this light, large cell carcinoma of the lung--as defined today--appears to be an outdated entity that needs to be reevaluated taking into account not only light microscopic findings but also the results of adjunct techniques such as immunohistochemistry and molecular profiling so that patients can benefit from more targeted therapies. This review examines the entity of pulmonary large cell carcinoma from these aspects and tries to delineate a practical diagnostic approach until further redefinition of this tumor is in place.

Neuroendocrine differentiation in acquired resistance to epidermal growth factor receptor tyrosine kinase inhibitor

Background

Small cell lung cancer (SCLC) transformation during epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) treatment in lung cancer has been suggested as one of possible resistance mechanisms.

Methods

We evaluated whether SCLC transformation or neuroendocrine (NE) differentiation can be found in the cell line model. In addition, we also investigated its effect on responses to conventional chemotherapeutic drugs of the SCLC treatment.

Results

Resistant cell lines to various kinds of EGFR-TKIs such as gefitinib, erlotinib, CL-387,785 and ZD6474 with A549, PC-9 and HCC827 lung adenocarcinoma cell lines were established. Among them, two resistant cell lines, A549/GR (resistant to gefitinib) and PC-9/ZDR (resistant to ZD6474) showed increased expressions of CD56 while increased synaptophysin, Rb, p16 and poly(ADP-ribose) polymerase were found only in A549/GR in western blotting, suggesting that NE differentiation occurred in A549/GR. A549/GR cells were more sensitive to etoposide and cisplatin, chemotherapeutic drugs for SCLC, compared to parental cells. Treatment with cAMP and IBMX induced synaptophysin and chromogranin A expression in A549 cells, which also made them more sensitive to etoposide and cisplatin than parental cells. Furthermore, we found a tissue sample from a patient which showed increased expressions of CD56 and synaptophysin after development of resistance to erlotinib.

Conclusion

NE differentiation can occur during acquisition of resistance to EGFR-TKI, leading to increased chemosensitivity.

Alterations in gene expression of proprotein convertases in human lung cancer have a limited number of scenarios

Proprotein convertases (PCs) is a protein family which includes nine highly specific subtilisin-like serine endopeptidases in mammals. The system of PCs is involved in carcinogenesis and levels of PC mRNAs alter in cancer, which suggests expression status of PCs as a possible marker for cancer typing and prognosis. The goal of this work was to assess the information value of expression profiling of PC genes. Quantitative polymerase chain reaction was used for the first time to analyze mRNA levels of all PC genes as well as matrix metalloproteinase genes MMP2 and MMP14, which are substrates of PCs, in 30 matched pairs of samples of human lung cancer tumor and adjacent tissues without pathology. Significant changes in the expression of PCs have been revealed in tumor tissues: increased FURIN mRNA level (p<0.00005) and decreased mRNA levels of PCSK2 (p<0.007), PCSK5 (p<0.0002), PCSK7 (p<0.002), PCSK9 (p<0.00008), and MBTPS1 (p<0.00004) as well as a tendency to increase in the level of PCSK1 mRNA. Four distinct groups of samples have been identified by cluster analysis of the expression patterns of PC genes in tumor vs. normal tissue. Three of these groups covering 80% of samples feature a strong elevation in the expression of a single gene in cancer: FURIN, PCSK1, or PCSK6. Thus, the changes in the expression of PC genes have a limited number of scenarios, which may reflect different pathways of tumor development and cryptic features of tumors. This finding allows to consider the mRNAs of PC genes as potentially important tumor markers.

Prognostic value of synaptophysin and chromogranin a expression in patients receiving palliative chemotherapy for advanced non-small-cell lung cancer

BACKGROUND

Chemotherapy is the principal treatment method for patients with advanced non-small-cell lung cancer (NSCLC). Treatment with platinum-based and novel chemotherapeutic regimens, compared to monotherapy, slightly increases the response rates to 20-40%. The predictive and prognostic values of molecular factors are highly variable; however, data on clinical-demographic factors are still burdened by significant limitations.

OBJECTIVES

The aim of this study was to assess the prognostic value of synaptophysin and chromogranin A protein expression in patients receiving palliative chemotherapy for advanced NSCLC.

METHODS

The study population consisted of 23 women and 116 men. The median age was 57.3 years. Expression of synaptophysin and chromogranin was assessed using a two-step model of immunohistochemical staining. Level 0 represented lack of activity, while level 1 represented its expression.

RESULTS

Expression of synaptophysin and chromogranin A was observed in 12 (8.6%) and 5 (3.6%) patients, respectively. The risk of death was significantly lower in patients with expression of synaptophysin (p = 0.008) and chromogranin A (p = 0.014). The 12- and 24-month survival rate of patients with synaptophysin expression was 64% (95% CI 0.35-0.93), while for patients without expression it was 46% (95% CI 0.36-0.56) and 16% (95% CI 0.07-0.25), respectively. The 12- and 24-month survival rate of patients with chromogranin expression was 80% (95% CI 0.44-1.00), while for chromogranin A-negative patients it was 47% (95% CI 0.37-0.57) and 19% (95% CI 0.10-0.28), respectively. We did not observe associations between expression of synaptophysin and chromogranin A and the other typical prognostic factors.

CONCLUSIONS

Expression of synaptophysin and chromogranin A was associated with a longer median overall survival and might have prognostic value. These results should be confirmed in a prospective study.

Neuroendocrine differentiation as an indicator of chemosensitivity and prognosis in nonsmall cell lung cancer

CONTEXT

Nonsmall cell lung cancers with neuroendocrine differentiation (NSCLC-ND) may demonstrate biologic behavior intermediate between NSCLC and small cell lung cancer (SCLC) with impact on prognosis.

METHODS

We analyzed 116 consecutive patients with Stage III and IV NSCLC who were diagnosed and treated between 2001 and 2006. Using immuno-histochemical staining for neuron-specific enolase (NSE), chromogranin A (ChrA), and synaptophysin (Syn), 29 (25%) NSCLC-ND were identified.

RESULTS

Expression of NSE was present in 22.4%, ChrA in 15.5% and Syn in 14.8% of patients with NSCLC. Therapeutic response was significantly better in the NSCLC-ND group and specimens with > 30% neuroendocrine (NE)-differentiated tumor cells showed favourable therapeutic response (P < 0.05). Multivariate binary logistic regression showed that percentage of NE positive tumor cells was a significant independent prognostic factor associated with a favourable outcome. Receiver operating characteristic (ROC) curves and areas under ROC curves confirmed that percentage of NE-differentiated tumor cells could be useful prediction factor of therapeutic response. Moreover, according to percentage of NE-differentiated tumor cells, optimal cutoffs and related sensitivities and specificities were determined for each markers.

CONCLUSION

Advanced-stage NSCLC with NE tumor cells are clinically less aggressive tumors. Percentage of NE-differentiated tumor cells identifies patients with favourable therapy response to paclitaxel-cisplatin.

Clinical relevance of neuroendocrine differentiation in non-small cell lung cancer assessed by immunohistochemistry: a retrospective study on 405 surgically resected cases

Neuroendocrine differentiation in non-small cell lung cancer is a common feature, which has caused contradictory conclusions concerning survival estimates and responsiveness to therapy. Aiming to clarify this conflict, we analyzed neuroendocrine differentiation by immunohistochemistry in 405 surgically resected non-small cell lung carcinomas using standardized tissue microarray platform and the currently recommended antibody panel consisting of chromogranin-A, synaptophysin, and neural-cell adhesion molecule. Diagnostic criteria provided by the World Health Organization were applied. Histological subtypes were primarily reclassified according to current guidelines, assisted by auxiliary immunohistochemistry. Extensive clinical data was acquired, enabling detailed clinicopathological correlation. Importantly, neuroendocrine differentiation assessed by immunohistochemistry showed no significant relation to overall survival estimates, which remained unaffected by histological subtype, neuroendocrine marker type, adjuvant therapy, and recurring disease. The only exception was a small group consisting of three large cell carcinomas, each expressing all three neuroendocrine markers and demonstrating decreased survival. In conclusion, additional immunohistochemical detection of neuroendocrine differentiation in non-small cell lung cancer is presently not of prognostic importance and does not justify a distinct consideration.

Phase II study of the anti-insulin-like growth factor type 1 receptor antibody CP-751,871 in combination with paclitaxel and carboplatin in previously untreated, locally advanced, or metastatic non-small-cell lung cancer

PURPOSE

We conducted a phase II study of combination of the anti-insulin-like growth factor 1 receptor antibody CP-751,871 with paclitaxel and carboplatin (PCI) in advanced treatment-naïve non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

Patients were randomly assigned (2:1) to paclitaxel 200 mg/m(2), carboplatin (area under the plasma concentration-time curve of 6), and CP-751,871 10 to 20 mg/kg (PCI(10), PCI(20)) or paclitaxel and carboplatin alone (PC) every 3 weeks for up to six cycles. PCI(10-20) patients could continue CP-751,871 (figitumumab) treatment after chemotherapy discontinuation. Patients treated with PC experiencing disease progression were eligible to receive CP-751,871 at investigator's discretion. An additional nonrandomized single-arm cohort of 30 patients with nonadenocarcinoma tumor histology receiving PCI(20) was enrolled on completion of the randomized study.

RESULTS

A total of 156 patients were enrolled onto the randomized portion of the study. Safety and efficacy information are available for 151 patients (98 patients treated with PCI and 53 patients treated with PC). Forty-eight patients treated with PCI received PCI(10) and 50 patients received PCI(20) in two sequential stages. Twenty of 53 patients treated with PC received CP-751,871 after disease progression. PCI was well tolerated. Fifty-four percent of patients treated with PCI and 42% of patients treated with PC had objective responses. Sixteen of 23 patients assessable for efficacy in the nonrandomized single-arm extension cohort also responded to treatment. Of note, 14 of 18 randomly assigned and 11 of 14 nonrandomly assigned patients treated with PCI with squamous cell carcinoma histology had response to treatment, including nine objective responses in bulky disease. Responses were also observed in two patients with squamous histology receiving CP-751,871 on PC discontinuation. PCI(20)/PC hazard ratio for progression-free survival was 0.8 to 0.56, according to censorship.

CONCLUSION

These data suggest that PCI(20) is safe and effective in patients with NSCLC.

Prognostic significance of synaptophysin in stage I of squamous carcinoma and adenocarcinoma of the lung

BACKGROUND

The prognostic significance of the presence of a neuroendocrine marker (synaptophysin, SY) was analyzed in stage I of squamous carcinoma and adenocarcinoma of the lung.

METHODS

A multicentric retrospective study was conducted with immunohistochemical staining in a single center of 318 patients resected for squamous carcinoma or adenocarcinoma in pathologic stage I.

RESULTS

In all, 162 cases of squamous carcinoma and 156 cases of adenocarcinoma were identified, which included 105 patients in stage IA (50 patients with squamous carcinoma and 55 patients with adenocarcinoma) and 213 in stage IB (112 with squamous carcinoma and 101 with adenocarcinoma). Eighty-six tumors showed a presence of SY+ (27%). Univariate analysis showed lower survival rates at 5 years for those patients older than 70 years of age compared with those patients younger than 70 years of age (60.35% vs 70.57%; P = .007) and for those patients with SY+ compared with those with SY- (52.48% vs 72.68%; P = .0017). Patients with SY+ tumors showed a higher rate of recurrence than patients with SY- tumors (50% vs 33.6%; P = .008). Multivariate analysis showed that those patients greater that 70 years of age (hazard ratio [HR], 1.74; 95% confidence interval [CI], 1.14-2.65) and the presence of SY (HR, 2.15; 95% CI, 1.40-3.30) were significant independent prognostic factors associated with a poor outcome.

CONCLUSIONS

Stage I of squamous carcinoma and adenocarcinoma of the lung with SY+ has a poor prognosis, with a higher frequency of recurrence and lower survival rates.

Prognostic value of circulating chromogranin A and soluble tumor necrosis factor receptors in advanced nonsmall cell lung cancer

BACKGROUND

Increased levels of chromogranin A (CgA), a protein secreted by many neuroendocrine cells, have been detected in sera of patients with neuroendocrine tumors or renal, hepatic, or heart failure. In patients with heart failure, serum CgA correlates with tumor necrosis factor-alpha (TNF) and soluble TNF receptors (sTNF-Rs), with important prognostic implications. The prognostic value of CgA and sTNF-Rs was investigated in advanced nonsmall cell lung cancer (NSCLC), a histologically heterogeneous group of tumors that may undergo neuroendocrine differentiation.

METHODS

CgA and sTNF-Rs were analyzed in the sera of 88 patients with NSCLC before chemotherapy by enzyme-linked immunoadsorbent assay (ELISA) and in tumors by immunohistochemistry.

RESULTS

Thirteen percent of patients had CgA values greater than the highest value observed in normal subjects (distribution range, 9-724 ng/mL and 28-196 ng/mL, respectively). Immunohistochemical studies showed no correlation between CgA expression in tumors and serum levels. Conversely, circulating CgA was associated with worse Eastern Cooperative Oncology Group (ECOG) performance status (PS) (P = .0005), more advanced stage (P = .042), and survival, with CgA being an independent prognostic factor of poor outcome (hazards ratio [HR] 1.31 for 100 ng/mL increase; 95% confidence interval [95% CI], 1.08-1.60 [P = .0071]). sTNF-R1 and sTNF-R2 were also associated with ECOG PS (P = .0001 and P = .02, respectively). sTNF-Rs was weakly correlated with circulating CgA (r = 0.39 for TNF-R1 and r = 0.40 for TNF-R2), suggesting a regulatory link between sTNF-Rs and CgA secretion.

CONCLUSIONS

Increased serum levels of CgA in NSCLC are independent from protein expression in tumors and more likely related to neuroendocrine response associated with worsening of patient condition. In addition to ECOG PS and stage, CgA is an independent indicator of poor prognosis.

Mechanisms of resistance to cisplatin and carboplatin

While cisplatin and carboplatin are active versus most common cancers, epithelial malignancies are incurable when metastatic. Even if an initial response occurs, acquired resistance due to mutations and epigenetic events limits efficacy. Resistance may be due to excess of a resistance factor, to saturation of factors required for tumor cell killing, or to mutation or alteration of a factor required for tumor cell killing. Platinum resistance could arise from decreased tumor blood flow, extracellular conditions, reduced platinum uptake, increased efflux, intracellular detoxification by glutathione, etc., decreased binding (e.g., due to high intracellular pH), DNA repair, decreased mismatch repair, defective apoptosis, antiapoptotic factors, effects of several signaling pathways, or presence of quiescent non-cycling cells. In lung cancer, flattening of dose-response curves at higher doses suggests that efficacy is limited by exhaustion of something required for cell killing, and several clinical observations suggest epigenetic events may play a major role in resistance.

Nonsmall cell lung carcinoma with neuroendocrine differentiation--an entity of no clinical or prognostic significance

The existence of non-small cell lung carcinoma with neuroendocrine differentiation as a distinct entity and its relevance for prognostic and treatment purposes is controversial. This study assesses the frequency and biologic and prognostic significance of neuroendocrine (NE) expression of synaptophysin (SNP), chromogranin (Ch), and neural cell adhesion molecule (N-CAM) using tissue microarray (TMA) and immunohistochemistry. Six hundred nine nonsmall cell lung carcinomas (NSCLCs) were reviewed for subclassification. TMA blocks were made using duplicate 0.6-mm-diameter tissue cores and slides stained with SNP, Ch, and N-CAM. Immunoreactivity was considered if 1% or more of tumor cells were positive. Hematoxylin and eosin-stained sections were subclassified as: 243 adenocarcinoma (ACA), 272 squamous cell carcinoma (SCC), 35 large cell carcinoma, 32 non-small cell carcinoma NOS, and 6 other (carcinosarcoma, giant cell carcinoma). Positivity for either marker was identified in 13.6% of NSCLC (76/558). NSCLC showed reactivity for Ch in 0.4% of cases (2/524), for SNP in 7.5% of cases (39/521) and for N-CAM in 8.6% of cases (44/511), whereas only 0.2% of cases (1/517) showed coexpression of SNP and Ch and none of all 3 markers. The assessment of NE differentiation in NSCLC is unnecessary and expensive and is of no clinical or prognostic significance. SNP or N-CAM stains a small minority of NSCLC, whereas Ch immunoreactivity is less common. Positivity for any 2 NE markers is rare. SNP is more likely to be expressed in adenocarcinoma (P=0.01) and N-CAM in squamous-cell carcinoma (P=0.008). Otherwise there was no correlation between immunoreactivity and tumor morphology. Disease specific and overall survival is not influenced by NE differentiation and therefore non-small cell lung carcinoma with neuroendocrine differentiation should not be a subclass distinct from the other NSCLC.

Up-regulation of expression of the ubiquitin carboxyl-terminal hydrolase L1 gene in human airway epithelium of cigarette smokers

Neuroendocrine differentiation is a common feature of lung cancer and increased numbers of neuroendocrine cells and their peptides have been described in chronic smokers. To understand the effects of cigarette smoking on the gene expression profile of neuroendocrine cells, microarray analysis with TaqMan confirmation was used to assess airway epithelial samples obtained by fiberoptic bronchoscopy from 81 individuals [normal nonsmokers, normal smokers, smokers with early chronic obstructive lung disease (COPD), and smokers with established COPD]. Of 11 genes considered to be neuroendocrine cell specific, only ubiquitin carboxyl-terminal hydrolase L1 (UCHL1), a member of the ubiquitin proteasome pathway, was consistently up-regulated in smokers compared with nonsmokers. Up-regulation of UCHL1 at the protein level was observed with immunohistochemical analysis of bronchial biopsies of smokers compared with nonsmokers. UCHL1 expression was evident only in neuroendocrine cells of the airway epithelium in nonsmokers; however, UCHL1 was also expressed in ciliated epithelial cells in smokers. This observation may add further weight to recent observations that ciliated cells are capable of transdifferentiating to other airway epithelial cells. In the context that UCHL1 is involved in the degradation of unwanted, misfolded, or damaged proteins within the cell and is overexpressed in >50% of lung cancers, its overexpression in chronic smokers may represent an early event in the complex transformation from normal epithelium to overt malignancy.

Neuroendocrine phenotype of non-small cell lung carcinoma: immunohistological evaluation and biochemical study

AIMS AND METHODS

The prevalence and distribution of neuroendocrine differentiation in non-small cell lung cancer (NSCLC) was estimated by assays for synaptophysin (SYN), chromogranin A (CgA), Leu7 and neuron-specific enolase (NSE). Serum NSE and CgA were determined in parallel to find the values of these markers for distinguishing neuroendocrine differentiation in NSCLC. Fifty-eight resected NSCLC specimens and 34 sera of NSCLC patients entered the study. Neuroendocrine differentiation was graded according to the percentage of neuroendocrine tumor cells as NE0--0%, NE1-NE4--1%->76%. Serum NSE <12.5 ng/mL and serum CgA <46 U/L were taken as cutoff levels.

RESULTS

63.8% (37/58) of NSCLC were scored as NE1-NE4 according to the SYN, CgA and Leu7 levels; 34.5% as NE1; 29.3% as NE2-NE4. 56.8% of tumors were positive for SYN, 34.4% for CgA, 22.4% for Leu7, and 79.3% for NSE. A significant relationship was found between tumor SYN and tumor CgA expression, and between tumor SYN expression and tumor stage. Adenocarcinomas showed a significantly higher rate of neuroendocrine differentiation than squamous cell carcinomas. All normal serum CgA levels corresponded to a lack of CgA expression in the tumors. The increased serum NSE levels presented by 26% of NSCLC patients (mainly <16 ng/mL) did not correlate with tumor NSE expression.

CONCLUSIONS

The prevalence of neuroendocrine differentiation in NSCLC varies and depends on the immunohistochemical criteria used; this warrants standardization of the immunohistochemical criteria for neuroendocrine differentiation in NSCLC. NSE expression in the tumor and a mild increase in serum NSE are poor markers for distinguishing neuroendocrine differentiation in NSCLC.

The prognostic significance of circulating neuroendocrine markers chromogranin a, pro-gastrin-releasing peptide and neuron-specific enolase in patients with advanced non-small-cell lung cancer

BACKGROUND

Chromogranin A (CGA), Pro-gastrin-releasing peptide (ProGRP) and neuron-specific enolase (NSE) are known as immunohistochemical tissue markers closely associated with neuroendocrine differentiation in non-small-cell lung carcinoma (NSCLC). The aim of the present study was to assess the value of serum levels of these markers in predicting response to chemotherapy and survival of patients with unresectable NSCLC.

METHODS

The study included 67 patients with advanced NSCLC treated with chemotherapy. Before treatment, serum levels of CGA, ProGRP and NSE were measured with commercial kits.

RESULTS

No association was found between serum NSE and age, gender, histology, performance status or extent of the disease. Distribution of serum CGA differed significantly according to gender and histology, with higher levels being found in men (p = 0.01) and in squamous cell carcinoma (p = 0.01). Serum ProGRP levels correlated with disease extent, being higher in patients with metastatic disease (M1) than in those with locoregional disease (M0; p = 0.02). The association of NSE, CGA and ProGRP levels with response to chemotherapy was not significant. While NSE had no impact on survival, the median survival was shorter for patients with elevated serum CGA and longer for patients with high ProGRP levels. Association with survival was significant when the Classification and Regression Tree (CART)-derived or median cutoff points were explored. On inclusion in multivariate Cox models, both CGA and ProGRP retained significance with high levels showing an opposite effect on survival [CART-derived cutoff points: CGA, relative risk (RR) -4.0; p < 0.001, and ProGRP, RR -0.4; p = 0.006, and median cutoff points: CGA, RR -1.8; p = 0.04, and ProGRP, RR -0.5; p = 0.03]. The combined use of CGA, ProGRP and NSE allowed for definition of two sets of patients with significantly different median survival times (25.2 vs. 8.8 months, p = 0.0001).

CONCLUSIONS

In the circulation, CGA and Pro-GRP appear to bear important information related to the prognosis for NSCLC patients before chemotherapy. While a high CGA before treatment was found as an unfavorable prognostic determinant, a high ProGRP conferred a survival advantage. The combined use of serum CGA, ProGRP and NSE may supply additional information to prognosis.

Neuroendocrine differentiation in extrahepatic bile duct carcinomas and its prognostic significance

Neuroendocrine differentiation is known to be one of the prognostic factors in many carcinomas. However, the characteristics of neuroendocrine differentiation are not well elucidated in extrahepatic bile duct (EBD) carcinomas. One hundred ninety-four cases of EBD carcinomas were analyzed using immunohistochemistry with synaptophysin and chromogranin. The tumors were graded as degree 0, 1, and 2 when the positive tumor cells were 5% or less, 6% to 25%, and 26% or more, respectively. Immunohistochemical results were compared with clinicopathologic variables and survival rate. Synaptophysin and chromogranin were positive in 54 (27.8%) and 74 (38.1%) cases, respectively. Thirty-four cases (17.5%) were positive for both synaptophysin and chromogranin, 20 (10.3%) and 40 cases (20.6%) were positive only for synaptophysin and for chromogranin, respectively, and 100 cases (51.6%) were negative for both markers. There was a significant survival difference between overall synaptophysin-positive (median, 27 months) and synaptophysin-negative (38 months) groups (P < .05). However, there was no survival difference between chromogranin-positive and chromogranin-negative groups. There was a significant survival difference between the dual-positive expression to synaptophysin and chromogranin group (median, 21 months) and the dual-negative expression group (median, 35 months; P < .05). In summary, synaptophysin expression was an important prognostic factor because synaptophysin-positive cases showed a worse prognosis than synaptophysin-negative cases. The more tumor cells expressed chromogranin, the poorer the survival. Therefore, immunohistochemical studies for neuroendocrine differentiation may be helpful in routine pathological examinations for evaluating the survival and the prognosis of patients with EBD carcinomas.

Role of IL-6 in neuroendocrine differentiation and chemosensitivity of non-small cell lung cancer

Interleukin-6 (IL-6) has been shown to regulate both growth and neuroendocrine (NE) differentiation in some types of human cancer cells, and erbB2 may be a critical component of IL-6 signaling. Non-small cell lung cancer (NSCLC) tumors that demonstrate NE properties have been suggested to have biological characteristics similar to small cell lung cancers with initial responsiveness to chemotherapy. We investigated whether IL-6 is implicated in the cell growth, NE differentiation, and chemosensitivity of NSCLC-NE cells. NSCLC-NE cells were treated with exogenous IL-6, and a subclone of an IL-6-transfected NSCLC cell line that constitutively expressed IL-6 receptor was also generated. These cells were assessed for cell proliferation by cell counting and 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assays, chemosensitivity to cisplatin and etoposide by MTT assays, and NE differentiation by observing morphological changes and immunoblotting for neuron-specific enolase (NSE). The IL-6-treated cells and the IL-6-transfected cells showed enhanced cell proliferation and downregulated NSE expression, but little change in chemosensitivity. In the culture medium, IL-6-transfected cells grew as looser aggregates than the parental cells. IL-6 could not activate the erbB genes. In conclusion, IL-6 can induce cell proliferation and NE dedifferentiation but has little effect on chemosensitivity in IL-6 receptor-expressing NSCLC-NE cells. The status of NSE expression is unlikely to be a crucial factor for chemosensitivity in NSCLC cells.

IL-6 induces neuroendocrine dedifferentiation and cell proliferation in non-small cell lung cancer cells

Interleukin-6 (IL-6) has been identified as an important growth regulator of lung cancer cells. Elevation of serum levels of IL-6 has been found in a subpopulation of lung cancer patients, but rarely in patients with benign lung diseases. Approximately 15% of non-small cell lung cancer (NSCLC) tumors exhibit neuroendocrine (NE) properties (NSCLC-NE) and have been suggested to have the biological characteristics similar to small cell lung cancer (SCLC) with early metastasis and initial responsiveness to chemotherapy. We recently showed that IL-6 promotes cell proliferation and downregulates the expression of neuron-specific enolase (NSE, one of the major NE markers) in NSCLC-NE cells. In this study, we show that IL-6 stimulates a transient increase of tyrosine phosphorylation of STAT3 in a dose-dependent fashion. Inhibition of STAT3 signaling pathway by either AG-490 (JAK2-specific inhibitor) or overexpression of STAT3Y705F (a dominant-negative STAT3) reverses NSE expression in IL-6- treated NSCLC-NE cells. In addition, IL-6 induces phosphorylation and activation of p38 MAPK. SB-203580, a p38 MAPK-specific inhibitor, inhibits IL-6-induced p38 MAPK phosphorylating activity and suppresses IL-6-stimulated cell proliferation. Together, our results indicate that STAT3 signaling pathway is involved in IL-6-induced NE differentiation and that p38 MAPK is associated with IL-6-stimulated growth regulation in NSCLC-NE cells. These data suggest that both kinase pathways play critical roles in the pathogenesis of NSCLC-NE malignancies, providing new molecular targets for future therapeutic approaches.

Neuroendocrine differentiation in non-small cell lung cancer and its relation to prognosis and therapy

AIMS

Histopathologists report the presence of neuroendocrine (NE) differentiation in non-small cell lung carcinoma (NSCLC) in up to a third of cases and are often questioned about its clinical relevance. The conclusions of previous studies have been inconsistent. This paper aims to provide an answer by examining a large series together with a comprehensive critique of the literature.

METHODS AND RESULTS

Four hundred and thirty-nine cases of NSCLC were examined, immunohistochemically, using antibodies to chromogranin A (CGA), synaptophysin (SYN) and CD56/neural cell adhesion molecule (NCAM). Three hundred and forty-one cases had been treated with surgical resection and the remainder with chemotherapy. The results were compared with clinical outcome. Thity-six percent of cases had positive staining for at least one NE marker. CGA was positive in 5.5% of cases, SYN in 16.5% and NCAM in 28%. There was no association between the presence of NE markers and survival in either the surgically treated group or the chemotherapy-treated group. There was also no association between NE markers and response to chemotherapy in the latter group.

CONCLUSIONS

The presence of immunohistochemically detected NE differentiation in NSCLC is not of prognostic significance.

Clinical responses of large cell neuroendocrine carcinoma of the lung to cisplatin-based chemotherapy

BACKGROUND

The efficacy of chemotherapy in patients with large cell neuroendocrine carcinoma of the lung (LCNEC) remains unclear.

METHODS

Patients with LCNEC who received cisplatin-based chemotherapy were identified by reviewing 567 autopsied and 2790 surgically resected lung cancer patients. The clinical characteristics and objective responses to chemotherapy in these patients were analyzed.

RESULTS

Overall, 20 cases of LCNEC were identified, including stage IIIA (n=3), stage IIIB (n=6), stage IV (n=6) and postoperative recurrence (n=5) cases. Six patients had received prior chemotherapy, and 14 were chemo-naive patients. The patients had received a combination of cisplatin and etoposide (n=9), cisplatin, vindesine and mitomycin (n=6), cisplatin and vindesine (n=4), or cisplatin alone (n=1). One patient showed complete response and nine showed partial response, yielding an objective response rate of 50%. The response rate did not differ between patients with the initial diagnosis of SCLC and those with the initial diagnosis of NSCLC, however, the response rate in chemo-naive patients (64%) was significantly different from that in previously treated patients (17%).

CONCLUSIONS

Our results suggest that the response rate of LCNEC to cisplatin-based chemotherapy was comparable to that of SCLC.

Prognostic implications of neuroendocrine differentiation and hormone production in patients with Stage I nonsmall cell lung carcinoma

BACKGROUND

Approximately 10-20% of nonsmall cell lung carcinomas (NSCLC) show neuroendocrine (NE) differentiation, as evaluated by panendocrine markers or ultrastructural evidence of dense-core secretory granules. However, little is known regarding the prevalence and clinical implications of NE differentiation in patients with Stage I NSCLC.

METHODS

The authors analyzed 220 consecutive patients with Stage I NSCLC (pT1-T2N0M0) among 2100 patients with primary lung carcinoma who underwent surgical treatment between 1987 and 1993. Using light microscopy and immunohistochemical staining for synaptophysin, chromogranin A, and respiratory tract-related hormones, 28 NSCLC specimens with NE differentiation (NSCLC-ND) and 11 large cell neuroendocrine carcinoma (LCNEC) specimens were identified.

RESULTS

The 28 NSCLC-ND specimens included 15 adenocarcinomas and 13 squamous cell carcinomas. Neoplastic cells with NE features never exceeded 20% in NSCLC-ND specimens, whereas neoplastic cells amounted to 20-90% in LCNEC specimens. NSCLC-ND specimens with > 5% NE-differentiated tumor cells showed increased Ki-67 labeling index (P = 0.007) and invasive phenotype, as evaluated by fascin immunoreactivity (P = 0.021). Patients with adenocarcinoma, but not with squamous cell carcinoma, who had > 5% NE-differentiated cells had a worse clinical course compared with patients who had ordinary NSCLC, with reduced overall survival (P = 0.017) and disease free survival (P = 0.049). In multivariate analysis, NE differentiation > 5% neoplastic cells in patients with adenocarcinoma independently predicted a poorer prognosis (hazard ratio, 2.61; 95% confidence interval, 0.99-6.85). Hormone production was restricted to chromogranin positive NSCLC-ND but did not affect prognosis.

CONCLUSIONS

Stage I adenocarcinomas with >or= 5% NE tumor cells are clinically aggressive tumors, similar to LCNEC. Hormone production identifies a more fully developed neuroendocrine phenotype but is not relevant to prognosis. The identification of NE-differentiated cells in patients with NSCLC may have clinical relevance.

Immunohistochemical neuroendocrine differentiation is an independent prognostic factor in surgically resected large cell carcinoma of the lung

The clinical significance of neuroendocrine (NE) differentiation is unclear in large cell carcinoma (LCC) of the lung. Fifty-five surgically resected carcinomas of the lung with an original pathologic diagnosis of LCC were reviewed histologically with special attention to NE morphology. Antibodies against neural cell adhesion molecule (NCAM), chromogranin A (CGA) and synaptophysin (SY) were used to confirm the NE differentiation. Thirteen (24%) cases were classified as large cell neuroendocrine carcinoma, 9 (16%) as LCC with NE differentiation, and 33 (60%) as pure LCC. There was no significant difference in overall survival between the three groups. When the 55 carcinomas were divided into three groups depending on the number of NE marker expression, there was significantly better overall survival in the NE > or = 2 (P = 0.02). Multivariate analysis proved NE > or = 2 was an independent predictor of survival. The number of NE markers was more important in terms of survival than histological sub-classification.

Neuroendocrine marker expression in cervical carcinomas of non-small cell type

Small-cell carcinomas of the uterine cervix are highly aggressive tumors. Up to 100% of these tumors express at least one neuroendocrine marker such as neuron-specific enolase (NSE), chromogranin A (CgA), and synaptophysin (SYN). In other tumor types such as non-small-cell carcinomas of the lung, colon, and prostate, the presence of these markers has been associated with a better prognosis in some studies, a worsened prognosis in others, or has had no prognostic effect in still other studies. However, little is known about their expression and prognostic significance in the common "non-small-cell" carcinomas of the uterine cervix. The primary tumors of 54 previously untreated patients with histologically confirmed non-small-cell carcinoma of the cervix uteri (squamous carcinoma, adenosquamous carcinoma, and adenocarcinoma) were analyzed by immunohistochemistry for expression of NSE, CgA, and SYN. The expression status was correlated to pathological characteristics and outcome. In addition, the expression of these markers was investigated in cervical carcinoma cell lines. None of the 54 tumors expressed NSE or CgA, although SYN was positive in five tumors (9%) of which four were squamous and one was adenocarcinoma. These five patients relapsed within the first 6 months of follow-up and four have died. Among eight cancer cell lines only one was positive for CgA and another one for SYN. We conclude that the neuroendocrine marker SYN is expressed in a small subset of non-small-cell carcinomas of the cervix and its expression seems to correlate with a poor outcome.

Prognostic factors in non-small cell lung cancer: a decade of progress

STUDY OBJECTIVES

To provide a systematic overview of the literature investigating patient and tumor factors that are predictive of survival for patients with non-small cell lung cancer (NSCLC), and to analyze patterns in the design of these studies in order to highlight problematic aspects of their design and to advocate for appropriate directions of future studies.

DESIGN

A systematic search of the MEDLINE database and a synthesis of the identified literature.

MEASUREMENTS AND RESULTS

The database search (January 1990 to July 2001) was carried out combining the MeSH terms prognosis and carcinoma, nonsmall cell lung. Eight hundred eighty-seven articles met the search criteria. These studies identified 169 prognostic factors relating either to the tumor or the host. One hundred seventy-six studies reported multivariate analyses. Concerning 153 studies reporting a multivariate analysis of prognostic factors in patients with early-stage NSCLC, the median number of patients enrolled per study was 120 (range, 31 to 1,281 patients). The median number of factors reported to be significant in univariate analyses was 4 (range, 2 to 14 factors). The median number of factors reported to be significant in multivariate analyses per study was 2 (range, 0 to 6 factors). The median number of studies examining each prognostic factor was 1 (range, 1 to 105 studies). Only 6% of studies addressed clinical outcomes other than patient survival.

CONCLUSIONS

While the breadth of prognostic factors studied in the literature is extensive, the scope of factors evaluated in individual studies is inappropriately narrow. Individual studies are typically statistically underpowered and are remarkably heterogeneous with regard to their conclusions. Larger studies with clinically relevant modeling are required to address the usefulness of newly available prognostic factors in defining the management of patients with NSCLC.

Cell membrane fluidity and prognosis of lung cancer

BACKGROUND

Membranes of tumor cells have been found to posses higher fluidity than membranes of non-tumor cells. Plasma membrane fluidity is significantly correlated with malignant potential of these cells.

METHODS

Seventy-five patients operated on for lung cancer were studied prospectively. During the operation, lung tumor samples were taken from the resected lung for evaluation by electron paramagnetic resonance. The fluidity variable H13, which is proportional to the plasma membrane fluidity, was determined from the electron paramagnetic resonance spectra. The association between H13 and survival was determined by survival analysis using Kaplan-Meier curves and Cox regression.

RESULTS

Pathologic TNM stage and the fluidity variable H13 were the only prognostic variables significantly associated with survival time in multivariate proportional hazards regression model. Thus, H13 was shown to be an independent prognostic variable for survival, which was also confirmed by a separate analysis relating the TNM stage and H13. Dividing the patients into two groups, one with an H13 value higher than the median and another with H13 below the median, resulted in significantly different survival curves (p = 0.01).

CONCLUSIONS

Patients with high plasma membrane fluidity, indicated by high H13 of the resected lung tumor tissue, seem to have poorer prognosis than those with less fluid membranes. We suggest that the fluidity variable could be used as an independent additional prognostic factor and a tool to identify patients who may be helped by adjuvant postoperative therapy.

The predictive value of neuroendocrine markers and p53 for response to chemotherapy and survival in patients with advanced non-small cell lung cancer

BACKGROUND

A minority of patients (30-40%) with advanced non-small cell lung cancer (NSCLC) have objective responses to chemotherapy. Therefore, defining molecular features that determine resistance or response to chemotherapy would have important implications in this disease. Several studies have suggested that patients whose tumors have neuroendocrine features may be more responsive to chemotherapy. In addition, increased expression of p53 may play a role in chemotherapy resistance in patients with NSCLC.

METHODS

The objective of this study was to analyze retrospectively, the correlation between marker expression and response to chemotherapy and survival using immunohistochemistry for neuroendocrine markers and p53. Ninety patients with unresectable stage III or IV NSCLC, treated with platinum based combination chemotherapy were evaluated. The pathological specimens were obtained prior to chemotherapy.

RESULTS

There was no statistically significant correlation between any individual marker and response to chemotherapy. However, patients with tumors with increased expression of p53 were more likely to have progressive disease following chemotherapy (P=0.02). Similarly, patients with tumors lacking neuroendocrine expression and with increased expression of p53 were more likely to have progressive disease when compared to patients with tumors with normal p53 expression and neuroendocrine differentiation (P=0.03). Normal expression of p53 along with the presence of neuroendocrine differentiation was a favorable factor for both survival (P=0.05) and time to disease progression (P=0.04) in the multivariate analysis.

CONCLUSION

The presence of neuroendocrine markers alone was not predictive of response to chemotherapy and did not impact on the survival of this group of patients with advanced stage NSCLC. The normal expression of p53 together with neuroendocrine differentiation seems to impact favorably on overall survival time and time to disease progression without significant improvement in response to chemotherapy.

Clinical significance of neuroendocrine phenotype in non-small-cell lung cancer

Non-small-cell lung carcinoma (NSCLC) describes a histologically heterogeneous group of tumours with variable clinical behaviour. Performance status, tumour stage and histological type have important prognostic implications, but clinical outcomes in individual patients remain unpredictable. A significant minority of NSCLCs (10%-30%) show neuroendocrine (NE) differentiation, and a number of studies have attempted to evaluate the therapeutic and prognostic significance of the expression of NE markers on the basis of the theoretical assumption that NE-differentiated tumours may be associated with an adverse prognosis and greater chemosensitivity. However, the results of these studies are conflicting: some have found that NE differentiation has a negative impact on survival, but others have failed to demonstrate any correlation with prognosis. Similar discrepancies have also been observed in terms of chemosensitivity. Nevertheless, these data are difficult to interpret because there is no gold standard defining NE differentiation, as is shown by the fact that the proportion of NE-differentiated NSCLCs varies according to the technique and marker used, although chromogranin A and synaptophysin show the best correlation with ultrastructural evidence of NE differentiation. In conclusion, there is no doubt that caution is required when interpreting the results of a number of studies questioning the clinical impact of the NE features of NSCLCs.

Pathology of lung cancer

This article reviews current concepts in pathologic classification of lung cancer based on 1999 World Health Organization (WHO)/International Association for the Study of Lung Cancer (IASLC) classification. Preinvasive lesions including squamous dysplasia/carcinoma in situ, atypical adenomatous hyperplasia and diffuse idiopathic pulmonary neuroendocrine cell hyperplasia are discussed in addition to current concepts of bronchioloalveolar carcinoma and neuroendocrine tumors.

Focal neuroendocrine differentiation in non-small cell carcinoma is not predicted by pre-operative routine investigation

AIMS

Between 10 and 35% of resected non-small cell carcinomas of the lung show focal neuroendocrine differentiation. The significance of this is uncertain but recent studies have suggested that these tumours may be more responsive to chemotherapeutic agents than other non-small cell carcinomas. This study was undertaken to determine if focal neuroendocrine differentiation in surgically resected non-small cell carcinomas could be predicted in patients who had undergone traditional routine pre-operative diagnostic investigations.

METHODS

Sixty-six consecutive resections for non-small cell carcinoma were reviewed for the presence of focal neuroendocrine morphology or positive immunohistochemical staining with neuroendocrine markers. Pre-operative biopsy and cytology samples from these patients were then sought for similar assessment.

RESULTS

Ten of the 66 cases showed either morphological or immunohistochemical evidence of neuroendocrine differentiation. All 10 patients had undergone pre-operative investigation including bronchoscopy but in only four were pre-operative diagnostic samples obtained (two cytology and two biopsies). None of these specimens showed features to suggest the presence of neuroendocrine differentiation within the resected tumours.

CONCLUSION

The presence of focal neuroendocrine features in an unselected series of resected non-small cell carcinomas was not predicted by traditional pre-operative diagnostic investigations This indicates that focal neuroendocrine differentiation in patients with unresectable non-small carcinoma cannot be reliably identified for inclusion in clinical trials using traditional investigate approaches.

Use of neuroendocrine markers, p53, and HER2 to predict response to chemotherapy in patients with stage III non-small cell lung cancer: a Cancer and Leukemia Group B study

Several studies have suggested that non-small cell lung cancer (NSCLC) patients whose tumors have neuroendocrine (NE) features may be more responsive to chemotherapy. In addition, increased expression of p53 and HER2 may confer relative chemotherapy resistance and shortened survival. The Cancer and Leukemia Group B performed a series of studies involving sequential chemotherapy followed by radiation for patients with unresectable stage III NSCLC. The objectives of this study were to analyze pathological specimens using immunohistochemistry for NE markers, p53 and HER2 to determine if there was a correlation between marker expression and response or survival. Of 160 eligible patients, 28 (18%) were not evaluable because of inadequate material. The percentage of specimens positive for markers was as follows: neuron-specific enolase 38%, Leu-7 2%, chromogranin A 0%, synaptophysin 5%, > or =2+NE markers 3%, p53 61%, and HER2 65%. There was no statistically significant correlation between any individual marker and response to induction chemotherapy or response to combined chemotherapy/radiation except for synaptophysin. Six of 6 (100%) synaptophysin positive tumors responded by the completion of all therapy compared with 69/125 (55%) synaptophysin negative tumors (P=0.04). None of the individual markers had a significant effect on survival in univariate analysis. Neuron-specific enolase was marginally significant in multivariate analysis (P=0.08). In conclusion, this study did not demonstrate that expression of NE markers, p53 and HER2 were predictive of response to chemotherapy, combined chemotherapy/radiation or for survival in this group of patients with stage III NSCLC. Future studies must employ either different markers or be performed on more adequate surgical specimens.

Prognostic factors in neuroendocrine lung tumors: a Spanish Multicenter Study. Spanish Multicenter Study of Neuroendocrine Tumors of the Lung of the Spanish Society of Pneumonology and Thoracic Surgery (EMETNE-SEPAR)

BACKGROUND

This study examines the experience of the Spanish Multicenter Study of Neuroendocrine Tumors of the Lung through the clinical data and behavior of patients treated for this pathologic process.

METHODS

From 1980 to 1997, 361 cases of neuroendocrine carcinomas (NEC) were treated surgically. Patients were enrolled in a protocol using the pathologic and follow-up reports. According to Dreslers' criteria, the cases were segregated into grade 1 (typical carcinoid), grade 2 (atypical carcinoid), grade 3 large cell type, and grade 3 small cell type. Several variables were reviewed in all patients. Statistical analysis was performed to determine whether clinical characteristics and differentiation were associated with significant differences in the prognosis.

RESULTS

A total of 261 cases of NEC were identified with grade 1, 43 with grade 2, and with grade 3: 22 of large and 35 of small cells. Five-year survival for different grades was as follows: grade 1, 96%; 2, 72%; 3 large cell type, 21%; and 3 small cell type, 14%. When a comparative analysis between typical and atypical carcinoids was performed a significant difference for mean age, tumor size, nodal metastases, and recurrence was observed. However, female sex, nodal metastases, and recurrence rate differed between atypical carcinoids and grade 3 NEC of large cells. A difference in recurrence rate was found between patients with both types of grade 3 NEC.

CONCLUSIONS

The progressive deterioration of tumor organization highlights that neuroendocrine tumors constitute a continuous spectrum. A careful observation of pathologic findings is necessary to individualize their prognostic factors.

Conventional clinicopathologic prognostic factors in surgically resected nonsmall cell lung carcinoma. A comparison of prognostic factors for each pathologic TNM stage based on multivariate analyses

BACKGROUND

A number of prognostic factors have been reported for resected nonsmall cell lung carcinoma. None of them, however, has been reported to have greater prognostic impact than the pathologic TNM staging system. The authors evaluated 18 conventional clinicopathologic prognostic factors in each pathologic stage.

METHODS

A retrospective study was conducted on surgically resected 836 lung carcinoma patients, and the following conventional prognostic factors were evaluated in multivariate analyses: age, gender, pack-year smoking, serum carcinoembryonic antigen and squamous cell carcinoma antigen levels, laterality of tumor, clinical N status, histologic type of tumor, greatest tumor dimension, grade of differentiation, pleural involvement, lymphatic invasion, vascular invasion, degree of fibrosing scarring, nuclear atypia, mitotic activity, and curativity of resection.

RESULTS

The overall 5-year survival rate was 63.8%. In 430 cases of pathologic Stage I disease, multivariate analyses revealed 3 significant prognostic factors: clinical N status (P < 0.001), vascular invasion (P = 0.001), and curativity of resection (P < 0.001). In 406 cases of more advanced disease, i.e., pathologic Stage II, IIIA, IIIB, or IV, multivariate analyses revealed 4 factors as significant: histology (P = 0.001), pathologic N status (P < 0.001), tumor size (P < 0.001), and curativity of resection (P = 0.002).

CONCLUSIONS

Conventional clinicopathologic prognostic factors had a different impact on prognosis in each pathologic TNM stage among patients who underwent surgical resection of nonsmall cell lung carcinoma. These factors should be analyzed separately in each pathologic TNM stage.

Analysis of K-ras, N-ras, H-ras, and p53 in lung neuroendocrine neoplasms

This study screened 11 samples of typical carcinoid (TC), 4 samples of atypical carcinoid (AC), 1 sample of large cell neuroendocrine carcinoma (LCNEC), and four metastases for point mutations in exons 5 to 8 of the p53 gene, and exons 1 and 2 of the K-ras. H-ras, and N-ras genes using polymerase chain reaction (PCR)-single-strand conformation polymorphism (SSCP) and direct sequencing and by immunohistochemistry for p53. Exon 1 of K-ras was mutated in two samples of low-grade AC and a metastasis from one of these tumors (GAT12 and AGT12, respectively). No mutations in N-ras or H-ras were found. Mutations in exons 5 and 8 of the p53 gene were identified in a high-grade AC and a LCNEC. Positive immunostaining for p53 was present in three samples, with only one genotypic mutation shown (LCNEC). In conclusion, point mutations of the p53 gene were infrequent in these pulmonary neuroendocrine tumors, did not correlate in all samples with immunostaining, and were associated with the higher-grade tumors. Second, the presence of K-ras mutations seems to be associated with the higher-grade carcinomas. Third, N-ras and H-ras mutations were not found with these pulmonary neuroendocrine tumors.

Large cell carcinoma of the lung: results of resection for a cure

OBJECTIVE

The effectiveness of surgical resection of large cell undifferentiated carcinoma of the lung remains poorly defined because of the histology's relatively low frequency, the tendency for presentation with high-stage disease, and the failure in most published series to separate large cell carcinomas from the other variants of non-small cell lung carcinoma. To define the effectiveness of surgical treatment of large cell carcinoma, we reviewed the Mayo Clinic experience over a 5-year period.

METHODS

We have retrospectively reviewed the Mayo Clinic experience with 61 patients with large cell carcinoma and 17 patients with adenocarcinoma with focal mucin production who came to surgical resection during the 5-year period of January 1, 1982, through December 31, 1986.

RESULTS

One-hundred percent 5-year follow-up was obtained. For the 61 patients with large cell carcinoma, the overall 5-year survival was 37%. Five-year survival for those with stage I tumors was 58% (n = 31), stage II 33% (n = 6), stage IIIA 15% (n = 20), stage IIIB 0% (n = 2), and stage IV 0% (n = 2). No significant differences in survival were detected between the 61 patients with large cell carcinoma and the 17 patients with solid adenocarcinoma with mucin production.

CONCLUSIONS

Our results suggest that there is a subset of patients with large cell carcinoma of the lung who can undergo resection with a reasonable expectation of long-term survival and that this survival is, stage for stage, comparable to or only slightly less than that achieved with other non-small cell lung carcinomas.

Immunoreactivity for LN2 and LN3 distinguishes small cell carcinomas from non-small cell carcinomas in the lung

Immunoreactivity to LN2 and LN3, monoclonal antibodies that recognize components of the class II major histocompatibility complex, was assessed in 72 cases of non-small cell lung carcinoma (NSCLC) (32 biopsy specimens, 40 resection specimens) and 64 cases of small cell carcinoma (56 biopsy specimens, 8 resections) of the lung. All cases were reviewed independently by three pathologists for histological classification. Only 1 of the 64 small cell carcinomas showed immunoreactivity for LN2, and none of the 64 cases showed reactivity for LN3. Among the non-small cell carcinomas, 25 of 48 cases were positive for LN2 and 43 of 71 were positive for LN3; the sensitivity was greater for adenocarcinoma (78.5%) than for squamous cell carcinoma (37%). A combined sensitivity of 64.7% was observed when the results of LN2 and LN3 were combined, and this sensitivity was not significantly diminished in the biopsy subset of cases (59.4%). Differentiation within histological subtypes of NSCLC (ie, well, moderate, or poorly differentiated) did not alter test sensitivity. In conclusion, LN2 and LN3, used alone or in combination, appear highly specific for non-small cell carcinoma and moderately sensitive in both biopsy and resection specimens; therefore, these antibodies may be diagnostically useful in distinguishing small cell from non-small cell carcinoma of the lung.

Analysis of neuroendocrine markers, HER2 and CEA before and after chemotherapy in patients with stage IIIA non-small cell lung cancer: a Cancer and Leukemia Group B study

Several studies have suggested that biochemical or molecular markers examined in non-small cell lung cancer carry prognostic or treatment response information. Non-small cell lung cancer patients whose tumors have neuroendocrine (NE) features may be more responsive to chemotherapy. In addition, increased expression of HER2 (c-erbB-2), a membrane-bound receptor with tyrosine kinase activity, has been associated with shortened survival. The Cancer and Leukemia Group B (CALGB) performed a study of patients with stage IIIA (N2 nodes positive) non-small cell lung cancer in which patients received initial chemotherapy followed by surgery, then post-operative therapy consisting of sequential chemotherapy and radiation therapy. Since all patients underwent mediastinoscopy, this provided an opportunity to compare pre- and post-chemotherapy tumor specimens to test the hypothesis that these proteins would predict treatment response. In particular, we hypothesized that the post-chemotherapy specimens would be enriched for NE marker negative cells because of the increased sensitivity of NE positive cells to chemotherapy. We performed immunohistochemical analysis for a panel of NE markers [neuron-specific enolase (NSE), Leu-7, chromogranin A (ChrA), synaptophysin (Syn)], HER2 and CEA to determine if there was an effect of therapy on the percentage of cells expressing these markers. Secondary endpoints were a correlation with chemotherapy response and survival. Slides were scored for intensity (0-4) and percentage of cells positive (0-4). Of 61 eligible patients, there were 38 with both pre- and post-chemotherapy specimens. When both intensity of staining and percentage of positive cells were considered, post-chemotherapy specimens had a higher percentage of positive NE markers compared with pre-chemotherapy. In addition, there was no correlation between NE marker, HER2 or CEA expression (prior to or post treatment) and response to chemotherapy or survival. These data do not support the hypothesis that NE positive tumor cells are preferentially killed by chemotherapy in patients with stage IIIA non-small cell lung cancer.

Reproducibility of neuroendocrine lung tumor classification

For a tumor classification scheme to be useful, it must be reproducible and it must show clinical significance. Classification of neuroendocrine lung tumors is a difficult problem with little information about interobserver reproducibility. We sought to evaluate the classification of typical carcinoid (TC), atypical carcinoid (AC), large-cell neuroendocrine carcinoma (LCNEC), and small-cell carcinoma (SCC) tumors as proposed by W.D. Travis et al (Am J Surg Pathol 15:529, 1991). Forty neuroendocrine tumors were retrieved from the Armed Forces Institute of Pathology (AFIP) files and independently evaluated by five lung pathologists and classified as TC, AC, LCNEC, or SCC (pure SCC, mixed small cell/large cell, and combined SCC). A single hematoxylin and eosin-stained slide from each case was reviewed. Each participant was provided a set of tables summarizing the criteria for separation of the four major categories. Agreement was regarded as unanimous if all five pathologists agreed, a majority if four agreed, and a consensus if three or more pathologists agreed. The kappa statistic was calculated to measure the degree of agreement between two observers. A consensus diagnosis was achieved in all 40 cases (100%), a majority agreement in 31 of 40 (78%), and unanimous agreement in 22 of 40 (55%) of cases. Unanimous agreement occurred in seven of SCC (70%), seven of TC (58%), four of AC (50%), and four of LCNEC (40%). A majority diagnosis was achieved in 11 of 12 (92%) of TC, 9 of 10 (90%) of SCC, 6 of 8 (75%) of AC, and 5 of 10 (50%) of LCNEC. Most of the kappa values were 0.70 or greater, falling into the substantial agreement category. The most common disagreements fell between LCNEC and SCC, followed by TC and AC, and AC and LCNEC. The highest reproducibility occurred for SCC and TC, with disagreement in 8% and 10% of the diagnoses, respectively. For TC, 10% of the diagnoses rendered were AC. For AC, 15% of the diagnoses were rendered as TC, with 2.5% called LCNEC and 2.5% called SCC. For LCNEC, 18% and 4% of the diagnoses were called SCC and AC, respectively. For SCC, 4% of the diagnoses were called AC and 4% were called LCNEC. Thus, using the classification scheme tested, a consensus diagnosis can be achieved for virtually all neuroendocrine lung tumors with substantial agreement between experienced lung pathologists. Classification of NE tumors is most reproducible for classification of TC and SCC but less reproducible for AC and LCNEC. These results indicate a need for more careful definition and application of criteria for TC versus AC and SCC versus LCNEC.

Neuroendocrine differentiation is an independent prognostic factor in chemotherapy-treated nonsmall cell lung carcinoma

BACKGROUND

Neuroendocrine differentiation can be identified in 10-30% of patients with nonsmall cell lung carcinoma (NSCLC) by immunohistochemical or electron microscopic techniques. However, its clinical significance is not well established.

METHODS

Tumors from 107 patients with Stage IIIA, IIIB, and IV NSCLC treated with cisplatin/etoposide with or without hydrazine in the North Central Cancer Treatment Group and Mayo Clinic protocols were analyzed immunohistochemically with antibodies to chromogranin A (CGA), Leu 7 (CD 57), and synaptophysin (SY). These results were compared with clinical outcomes.

RESULTS

Keratin AE1/AE3, used as a control, was positive in 99.1% of cases; 34.6% had positive staining for at least 1 neuroendocrine marker, and 11.3% had positive staining for 2 or more markers. CGA was positive in 4.7%, Leu 7 in 18.7%, and SY in 24.3% of cases. A significant increase in survival was seen in patients with tumors expressing any one neuroendocrine marker or any combination of neuroendocrine markers (P < or = 0.01). There was no correlation between the presence of neuroendocrine differentiation and either response to chemotherapy or time to disease progression (P > 0.3), nor was there any correlation between chemotherapy response, time to progression, or survival with staining intensity or percent of cells positive per case.

CONCLUSIONS

Neuroendocrine differentiation may be of prognostic significance in patients with advanced stage NSCLC treated with chemotherapy.

The value of neuroendocrine markers in non-small cell lung cancer: a comparative immunohistopathologic study

In order to estimate the value of immunohistochemical identification of neuroendocrine (NE) differentiation markers in non-small cell lung carcinomas (NSCLCs), we investigated the expression of five neuroendocrine and neural differentiation-related antigens in 51 NSCLCs. Additionally, 20 epithelial lung tumors with NE differentiation [15 carcinoids and five small cell lung carcinomas (SCLCs)] and 61 epithelial tumors of various other origin (breast, prostate, colon and head-neck carcinomas) were studied. An indirect two-stage immunoperoxidase method was performed in formalin-fixed and paraffin-embedded tissue specimens, by using commercially available monoclonal antibodies. These antibodies are directed against neuron-specific enolase (NSE), chromogranin-A and Leu-7 which are general markers of NE differentiation, bombesin, which is a specific NE secretory product and neurofilament triplet protein (NFTP), an intermediate filament protein of neuronal differentiation. All five markers demonstrated a positive immunoreactivity in NSCLCs, equally distributed to all three histologic subtypes, ranging from 16 to 47% of the cases (NSE 47%, bombesin 21.5%, Leu-7 21.5%, chromogranin-A 18% and NFTP 16%). Most of the carcinoids and SCLCs expressed multiple or all NE markers. The other four epithelial tumors showed a positive immunoreactivity for bombesin, Leu-7 and NFTP, ranging from 11 to 40% of the cases. Chromogranin-A was not expressed in any of these tumors, whereas NSE was demonstrated only in 17% of breast carcinomas. The following remarks can be drawn from this study: (1) some NSCLCs showed immunophenotypic NE differentiation; (2) among all the markers used, NSE was the most sensitive (sensitivity, 100%) and chromogranin-A the most specific (specificity, 100%); and (3) NSE and chromogranin-A appear to be the most valuable and useful indicators of probable neuroendocrine differentiation in lung epithelial tumors.