The prognostic value of NCAM, p53 and cyclin D1 in resected non-small cell lung cancer

The Molecular and Cellular Strategies of Glioblastoma and Non-Small-Cell Lung Cancer Cells Conferring Radioresistance

Ionizing radiation (IR) has been shown to play a crucial role in the treatment of glioblastoma (GBM; grade IV) and non-small-cell lung cancer (NSCLC). Nevertheless, recent studies have indicated that radiotherapy can offer only palliation owing to the radioresistance of GBM and NSCLC. Therefore, delineating the major radioresistance mechanisms may provide novel therapeutic approaches to sensitize these diseases to IR and improve patient outcomes. This review provides insights into the molecular and cellular mechanisms underlying GBM and NSCLC radioresistance, where it sheds light on the role played by cancer stem cells (CSCs), as well as discusses comprehensively how the cellular dormancy/non-proliferating state and polyploidy impact on their survival and relapse post-IR exposure.

Prognostic markers in lung cancer: is it ready for prime time?

Non-small cell lung cancer (NSCLC) is a heterogeneity disease and to date, specific clinical factors and tumor stage are established as prognostic markers. Nevertheless, prognosis within stage may vary significantly. During the last 3 decades, genes/proteins that drive tumor initiation and progression, such as oncogenes and tumor suppressor genes have been studied as additional potential prognostic markers. The protein markers as evaluated by immunohistochemistry (IHC) have previously dominated these studies. However, with the development of high-throughput techniques to interrogate genome wide genetic or gene expression changes, DNA (copy number and mutation) and RNA (mRNA and microRNA) based markers have more recently been studied as prognostic markers. Largely due to the heterogeneity and complexity of NSCLC, single gene markers including KRAS mutation has not been validated as strong prognostic markers. In contrast, several gene expression signatures representing mRNA levels of multiple genes have been developed and validated in multiple microarray datasets of independent patient cohorts. The salient features of these gene signatures and their potential value to predict benefit from adjuvant chemotherapy is discussed.

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.

Cyclin D1 in non-small cell lung cancer: a key driver of malignant transformation

PURPOSE

To review the evidence implicating the deregulation of cyclin D1 in the pathogenesis of non-small cell lung cancer (NSCLC), and to discuss the opportunities for targeted clinical intervention.

METHODS

Data published until June 2006 are summarized, and previously unpublished results from our own research are included.

RESULTS

In normal cells, cyclin D1 complexes with and activates cyclin-dependent kinases (CDK) and acts as a transcriptional regulator. The protein is frequently overexpressed in a wide range of cancers, sometimes coincident with CCND1 (cyclin D1) gene amplification (5-20% of tumours). A low level of somatic mutations have been seen in certain tumours. CCND1 is amplified in NSCLC and cyclin D1 is frequently overexpressed in tumours and pre-invasive bronchial lesions, generally from one parental allele. Mutation analyses revealed a frequent CCND1 gene polymorphism (A870G) that modulates alternative splicing and allows expression of an alternative cyclin D1 transcript (transcript cyclin D1b). The encoded cyclin D1b protein lacks a specific phosphorylation site required for nuclear export. Genotype has been correlated with the risk and/or severity of disease or drug response across a range of malignancies, including lung cancer. Together, these findings suggest a strong pathological role for cyclin D1 deregulation in bronchial neoplasia.

CONCLUSION

Current data indicate that cyclin D1 overexpression is not a consequence of, but rather a pivotal element in the process of malignant transformation in the lung and other tissues. This understanding may open new avenues for lung cancer diagnosis, treatment and prevention.

Immunohistochemical markers of prognosis in non-small cell lung cancer: a review and proposal for a multiphase approach to marker evaluation

Characteristics of the tumour that affect and predict the survival outcome of patients with cancer are prognostic markers for cancer. In non-small cell lung carcinoma (NSCLC), stage is the main determinant of prognosis and the basis for deciding options for treatment. Patients with early-stage tumour are treated by complete surgical resection, which is curative in 40-70% of patients. That there are other factors important in determining the biology of these tumours, especially genes that have a role in metastasis, is indicated. Such factors could potentially be used to further classify patients into groups according to substages that may be treated differently. During the past decade, a large number of proteins that are putatively important in carcinogenesis and cancer biology have been studied for their prognostic value in NSCLC, but none of them have been proved to be sufficiently useful in clinical diagnosis. Several markers (epidermal growth factor receptor, human epidermal growth factor receptor 2, Ki-67, p53 and Bcl-2) have been studied exhaustively. Ki-67, p53 and Bcl-2 are suggested to be important but weak prognostic markers, by meta-analyses of the results. Cyclin E, vascular endothelial growth factor A, p16(INK4A), p27(kip1) and beta-catenin are promising candidates, but require further study in large randomised clinical trial samples by using standardised assays and scoring systems. Some issues and inconsistencies in the reported studies to date are highlighted and discussed. A guideline for a multi-phase approach for conducting future studies on prognostic immunohistochemistry markers is proposed here.

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.

Prognostic value of cyclin D1 overexpression in correlation with pRb and p53 status in non-small cell lung cancer (NSCLC)

PURPOSE

The aim of this study was to assess the impact of cyclin D1 overexpression (considered separately or jointly with previously assessed p53 and pRb statuses) on survival in a group of 111 surgically treated non-small cell lung cancer patients (NSCLC).

METHODS

Cyclin D1 accumulation was assessed immunohistochemically, with the use of monoclonal antibody (DCS-6, DakoCytomation) and the alkaline phosphatase-anti-alkaline phosphatase (APAAP) technique.

RESULTS

Overexpression of cyclin D1 was found in 55 samples (49%), whereas the altered phenotypes cyclin D1+/p53+ or cyclin D1+/pRb- were found in 23 (22%) and 9 samples (9%), respectively. Statistical analysis was performed for different cut-off values and the only significant differences were found if samples with some expression of each protein were considered positive. There was no relationship between cyclin D1 overexpression and major clinicopathological factors, including p53 expression; however, there was a direct correlation between cyclin D1 and pRb protein expression (p=0.007). Cyclin D1 accumulation did not influence patients' survival. Of all possible cyclin D1/p53, cyclin D1/pRb and cyclin D1/p53/pRb phenotypes, patients with cyclin D1-/p53+ phenotype had shortened overall survival compared to other patients (p=0.027, HR=1.8). In the multivariate analysis, the only variable associated with shortened overall and disease-free survival was the stage of disease (p<0.001).

CONCLUSIONS

These results suggest the lack of prognostic value of cyclin D1 overexpression in NSCLC patients.

Neural adhesion molecule (N-CAM) in pleomorphic adenoma and carcinoma ex-pleomorphic adenoma

BACKGROUND

The neural cell adhesion molecule (N-CAM) has been implicated in the behaviour of the adenoid cystic carcinoma. In vitro, it was demonstrated that N-CAM inhibits cell invasion. The aim of this study was to search for N-CAM in the most common salivary gland tumour that has a malignant counterpart.

METHODS

We investigated the presence of N-CAM in pleomorphic adenoma and its malignant counterpart, the carcinoma ex-pleomorphic adenoma, using the immunohistochemistry technique.

RESULTS

Neural cell adhesion molecule was expressed in all cases of pleomorphic adenoma, strongly labelling the luminal cells of the double-layered ductform structures. This expression was weaker in neoplastic myoepithelial cells and progressively diminished at a distance from the luminal cells. In carcinoma, ex-pleomorphic adenoma N-CAM was either totally absent or faintly present at the apical pole of the few luminal cells.

CONCLUSIONS

As a result of the peculiar distribution of N-CAM in pleomorphic adenoma, we speculated that N-CAM behaves as a tumour-suppressor molecule, which is expressed in the benign neoplasm and which is down-regulated after malignancy, when the tumour assumes an invasive behaviour.

The Role of Apoptosis-Related Genes in non—small-Cell Lung Cancer

Both intrinsic and acquired resistance to chemotherapeutic drugs are major obstacles in the treatment of non-small-cell lung cancer. Apart from classical drug resistance mechanisms, the failure of tumor cells to undergo apoptosis also plays an important role in drug resistance. Mutations and defects in the apoptotic pathway are, therefore, additional factors that determine drug resistance. The tumor suppressor gene p53, the retinoblastoma gene, and the bcl-2 family members are important factors in this pathway. Recently much attention has been drawn to different apoptotic pathways induced by naturally occurring death receptor ligands (such as tumor necrosis factor, Fas ligand, and tumor necrosis factor-related apoptosis-inducing ligand) or induced by drugs that affect the downstream pathway from the epidermal growth factor receptor. Insight regarding the proteins that determine sensitivity for chemotherapeutic drugs could provide new targets for cancer treatment, which may help to at least partly overcome drug resistance in non-small-cell lung cancer

Role of p53 as a prognostic factor for survival in lung cancer: a systematic review of the literature with a meta-analysis

The role of p53, as a prognostic factor for survival in lung cancer, is controversial and the purpose of the present systematic review of the literature is to determine this effect. Published studies were identified with the objective to aggregate the available survival results after a methodological assessment using a scale specifically designed by the European Lung Cancer Working Party (ELCWP). To be eligible, a study had to deal with p53 assessment in lung cancer (primary site) only, and to provide a survival comparison according to the p53 status. Among the 74 eligible papers, 30 identified p53 abnormalities as a univariate statistically significant poor prognostic factor and 56 provided sufficient data to allow survival results aggregation. There was no significant difference between the trials that either showed or did not show a prognostic effect of p53 according to the methodological score or to the laboratory technique used. The studies were categorized by histology, disease stage, treatment and laboratory technique. Combined hazard ratios suggested that an abnormal p53 status had an unfavourable impact on survival: in any stage nonsmall cell lung cancer (NSCLC) the mean (95% confidence interval) was 1.44 (1.20-1.72) (number of studies included in the subgroup was 11), 1.50 (1.32-1.70) in stages I-II NSCLC (n=19), 1.68 (1.23-2.29) in stages I-IIIB NSCLC (n=5), 1.68 (1.30-2.18) in stages III-IV NSCLC (n=9), 1.48 (1.29-1.70) in surgically resected NSCLC (n=20), 1.37 (1.02-1.85) in squamous cell carcinoma (n=9), 2.24 (1.70-2.95) in adenocarcinoma (n=9), 1.57 (1.28-1.91) for a positive immunohistochemistry with antibody 1801 (n=8), 1.25 (1.09-1.43) for a positive immunohistochemistry with antibody DO-7 (n=16), and 1.65 (1.35-2.00) for an abnormal molecular biology test (n=13). Data were insufficient to determine the prognostic value of p53 in small cell lung cancer. In each subgroup of nonsmall cell lung cancer, p53 abnormal status was shown to be associated with a poorer survival prognosis.

Molecular genetic abnormalities in premalignant lung lesions: biological and clinical implications

Lung cancer is a leading cause of cancer death worldwide; however, despite major advances in cancer treatment during the past two decades, the prognostic outcome of lung cancer patients has improved only minimally. This is largely due to the inadequacy of the traditional screening approach, which detects only well-established overt cancers and fails to identify precursor lesions in premalignant conditions of the bronchial tree. In recent years this situation has fundamentally changed with the identification of molecular abnormalities characteristic of premalignant changes; these concern tumour suppressor genes, loss of heterozygosity at crucial sites and activation of oncogenes. After considering the morphological modifications that occur in premalignant lesions of the bronchial tree, we analyse the alterations occurring in a series of relevant genes: p53 and its functional regulation by MDM2 and p14ARF, p16INK4, p15INK4b, FHIT, as well as LOH at important sites such as 3p, 8p, 9p and 5q. Activation of oncogenes is considered for K-ras, the cyclin D1, the heterogeneous nuclear ribonucleoprotein A2/B1 (hnRNPA2/B1), and finally the c-myc oncogene. The expression of c-myc is influenced strongly by the presence of growth factors (GFs), among which EGF is of prime importance, as well as its receptor coded for by the c-erbB-2 oncogene. Basic knowledge at the molecular level has extremely important clinical implications with regard to early diagnosis, risk assessment and prevention, and therapeutic targets. The novel techniques for early diagnosis and screening of premalignant lung lesions, such as fluorescence bronchoscopy, endobronchial ultrasound, spiral computed tomography combined with precise spatial localization techniques, should basically change the approach to the problems raised by this disease and allow for an increased discovery rate of incipient lesions. Sequential applications will lead to the identification of individuals/populations at high risk, while the availability of accurate 'intermediate end points' will enable the effects of preventive trials to be monitored. Finally, the same molecular abnormalities may serve as 'starting points' for innovative treatments designed to restore the altered functions to normality. Recent developments in our knowledge and understanding of the molecular genetic abnormalities in premalignant lung lesions open an era of hope.

Expression of cyclin E and cyclin D1 in non-small cell lung cancers

The relationships between overexpression of cyclin D1 or cyclin E and clinicopathological factors were investigated in 157 patients with non-small cell lung cancers (NSCLCs) using immunohistochemical analysis. Fifty-eight cases of NSCLCs (58/157, 37%) showed the overexpression of cyclin D1, and 64 cases (64/157, 41%) were positive for cyclin E. Cyclin E and cyclin D1 were infrequently concurrently overexpressed (17/157, 10.8%). Overexpression of cyclin E was more frequently observed in squamous cell carcinoma (29/57, 51%) compared with that in adenocarcinoma (28/86, 33%) (P<0.05). In addition, overexpression of cyclin E was more frequently observed in poorly or moderately differentiated NSCLCs (52/103, 50%) than in well-differentiated ones (12/54, 22%) regardless of their histological types (P<0.01). On the contrary, there was no statistically significant relationship between cyclin D1 overexpression and histological types or grade of tumor differentiation. These findings suggest that expression of cyclin E was frequently independent of that of cyclin D1 and played some roles in the grade of tumor differentiation in NSCLCs.

The expression of cyclins D1 and E in predicting short-term survival in squamous cell carcinoma of the lung

Cyclins D1 (cD1) and E (cE) are G1 phase cyclins believed to participate in the pathogenesis of malignancy. Overexpression of cD1 has been reported to influence prognosis in squamous cell carcinomas (SCC) of the larynx, but was not significant in a limited study of non-small cell lung cancers (NSCLC). Altered expression of cE has been proposed as another potential prognostic marker in malignancy but its possible role in NSCLC has not been elucidated. In order to determine the prognostic value of cD1 and cE in NSCLC, paraffin-embedded sections of 467 NSCLC were immunostained with monoclonal antibody to cD1 (1:500, PharMingen, San Diego, CA) and 400 NSCLC with MA to cE (1:2500, PharMingen) using an enhanced sensitivity avidin-biotin complex technique. The number of tumor cells with nuclear and/or cytoplasmic immunopositivity was graded on a scale of: 0 = less than 1%, 1 = 1 to 10%, 2 = 10 to 25%, 3 = 25 to 50%, 4 = 50 to 75%, 5 = more than 75%. Results were correlated with survival by Kaplan-Meier survival plot using Stat-View software (Abacus Concepts, Berkeley, CA). Overall, 426 NSCLC with cD1 and 360 NSCLC with cE had adequate follow-up (median, 76 mo) for survival analysis. Both cyclins independently showed significance in prognosis of SCC but not other cell types. For cD1, absence of immunostaining was associated with worse prognosis than any immunopositivity for all stages of SCC (P = .025). For cE, Stage I and II SCC with less than 50% immunopositivity had a worse prognosis (P = .029). Of 70 Stage I and II SCC immunostained for both monoclonal antibodies, 55% of patients with tumors that demonstrated both absence of cD1 staining and cE immunopositivity in less than 50% of cells were dead at 5 years compared to 35% of patients with tumors that demonstrated positive staining with cD1 and cE immunopositivity in more than 50% of cells. These results strongly suggest cD1 and cE can independently predict prognosis in early stage SCC. Worse prognosis was associated with loss of expression, consistent with mechanisms other than overexpression of these cyclins in the progression of SCC.

NCAM (neural cell adhesion molecules) expression in malignant mesotheliomas

Neural cell adhesion molecules (NCAM) are adhesion molecules expressed by neural and neuroendocrine tumors and a few biphasic tumors such as synovialosarcomas and breast phyllode tumors. To investigate NCAM expression in mesotheliomas, we studied 26 cases of epithelioid (n = 12), biphasic (n = 11), and sarcomatoid (n = 3) malignant mesotheliomas (MM), in comparison with normal mesothelium, and 50 primary non-small cell lung carcinomas (NSCLC) (25 adenocarcinomas [ADC] and 25 squamous cell carcinomas [SCC]), using electron microscopy as a gold standard for recognition of MM. NCAM reactivity using 123C3 antibody was compared with that of NE markers such as chromogranin A and synaptophysin. Although normal mesothelium remains negative, NCAM was expressed in 19 of 26 MM (73%) with a membranous staining on frozen or paraffin sections. In 6 of 12 epithelioid MM, the tumor cells expressed NCAM, whereas in 5 cases stromal fibroblasts showed a strong but focal staining. In 11 biphasic MM, 4 presented an NCAM reactivity of both epithelioid and spindle cell components, whereas in 7, only fusiform component was NCAM positive. Two of 3 sarcomatoid MM showed an NCAM expression. Chromogranin expression was never seen, whereas synaptophysin was noticed in 2 cases. No case of NSCLC showed membranous 123C3 staining, whereas 2 ADC weakly expressed synaptophysin. We conclude that NCAM expression in MM is reminiscent of its expression in mesoderm during fetal life and consistent with that reported in other biphasic tumors. These data show that NCAM expression occurs in 73% of MM, highly exceeding that observed in lung cancer.

A study of smoking, p53 tumor suppressor gene alterations and non-small cell lung cancer

PURPOSE

The purpose of this study was to investigate the relationship between smoking and p53 tumor suppressor gene alterations, and their association with clinicopathologic features and prognosis in non-small cell lung cancer (NSCLC).

METHODS

For 111 of 119 stage I-III NSCLC patients that had been followed prospectively, tumor p53 protein accumulation was measured immunohistochemically (IHC). Staining was evaluated as a score (p53IHCS) combining intensity and percent distribution.

RESULTS

Forty-eight of 111 (43%) tumors had p53IHCS > 1. p53 IHC was associated with increasing tumor size (T) (p = 0.035), nodal status (N) (p = 0.091), stage (p = 0.054), and histology: squamous cell carcinoma (70%) and adenocarcinoma (27%) (p = 0.0002). In logistic regression analysis, p53 IHC was associated with squamous cell histology versus other histotypes [adjusted odds ratio (OR)5.90, 95% confidence interval (CI) 2.34-14.90]. p53 IHC was not associated with smoking variables. In multivariate proportional hazards analysis, p53IHCS and pack-years smoked (PY), both as continuous variables, were negative prognostic factors. The adjusted hazard ratios (HR) for the survival outcome recurrence for p53IHCS and PY were 1.20 (95% CI 1.02-1.40) and 1.03 (95% CI 1.01-1.04), and for death due to recurrent disease (DRD) were 1.35 (95% CI 1.11-1.64) and 1.03 (95% CI 1.01-1.04), respectively. Comparing the 75th percentile to the baseline 0, the adjusted HR for p53IHCS (5 vs. 0) was 4.5 and for PY (55 vs. 0) was 5.1 for the outcome DRD. Both variables demonstrated a dose-response relationship with survival.

CONCLUSIONS

PY and p53IHCS are significant, independent and important predictors of recurrence and DRD in stage I-III NSCLC.

Cyclin D1 overexpression is an indicator of poor prognosis in resectable non-small cell lung cancer

Cyclin D1 is one of the G1 cyclins that control cell cycle progression by allowing G1 to S transition. Overexpression of cyclin D1 has been postulated to play an important role in the development of human cancers. We have investigated the correlation between cyclin D1 overexpression and known clinicopathological factors and also its prognostic implication on resected non-small-cell lung cancer (NSCLC) patients. Formalin-fixed and paraffin-embedded tumour tissues resected from 69 NSCLC patients between stages I and IIIa were immunohistochemically examined to detect altered cyclin D1 expression. Twenty-four cases (34.8%) revealed positive immunoreactivity for cyclin D1. Cyclin D1 overexpression is significantly higher in patients with lymph node metastasis (50.0% vs 14.4%, P = 0.002) and with advanced pathological stages (I, 10%; II, 53.8%; IIIa, 41.7%, P = 0.048; stage I vs II, IIIa, P = 0.006). Twenty-four patients with cyclin D1-positive immunoreactivity revealed a significantly shorter overall survival than the patients with negativity (24.0 +/- 3.9 months vs 50.1 +/- 6.4 months, P = 0.0299). Among 33 patients between stages I and II, nine patients with cyclin D1-positive immunoreactivity had a much shorter overall survival (29.7 +/- 6.1 months vs 74.6 +/- 8.6 months, P = 0.0066). These results suggest that cyclin D1 overexpression is involved in tumorigenesis of NSCLCs from early stage and could be a predictive molecular marker for poor prognosis in resectable NSCLC patients, which may help us to choose proper therapeutic modalities after resection of the tumor.

Neural cell adhesion molecule expression: prognosis in 889 patients with resected non-small cell lung cancer

INTRODUCTION

In search of factors that might predict outcome in patients with resected non-small cell lung cancer (NSCLC), we studied the reactivity of monoclonal antibody 123C3. This marker of neuroendocrine (NE) differentiation is directed against neural cell adhesion molecules (NCAM). Although NCAM can often be demonstrated in small cell lung cancer and carcinoids as a tumor antigen, not many data exist on NCAM in NSCLC.

PATIENTS AND METHODS

From 1983 through 1995, in 889 patients with NSCLC, who underwent pulmonary resection, 123C3 reactivity was tested. NCAM was correlated with tumor histology, p-TNM stage, and 5-year survival. Large cell NE carcinomas were excluded. Monoclonal antibody-1 (MOC-1) was also tested on most specimens.

RESULTS

Reactivity of 123C3 does not correlate with tumor histology, p-TNM stage, or 5-year survival. In addition, MOC-1 reactivity was not significantly related to prognosis.

CONCLUSIONS

Positive reactivity with 123C3, indicating NE differentiation, does not have predictive value in NSCLC. Also, tumor histology or stage did not correlate with 123C3 reactivity. Reactivity of MOC-1 did not contribute to prediction of prognosis. Whether there is more chemosensitivity in NSCLC-NE than in NSCLC without NE differentiation remains an important question that is not addressed by our present study.

Neural cell adhesion molecules (NCAM) and NCAM-PSA expression in neuroendocrine lung tumors

Neural cell adhesion molecules (NCAM) represent specific markers of neuroendocrine (NE) differentiation in lung cancer. Because the polysialic acid form (NCAM-PSA) has reduced adhesion properties, we hypothesized that NCAM-PSA expression could favor metastatic spread. Immunostaining of NCAM and NCAM-PSA were therefore compared in 120 NE lung tumors, including 17 typical carcinoids, 3 atypical carcinoids, 30 large cell NE carcinomas and 70 small cell lung carcinomas, as compared with 25 adenocarcinomas and 25 squamous cell carcinomas. Neural cell adhesion molecules were negative in adenocarcinomas and squamous cell carcinomas but were constantly expressed in all NE tumors from typical carcinoids to small cell lung carcinomas. NCAM-PSA expression was significantly more frequent in high-grade tumors, with 24 of 30 positive cases in large cell NE carcinomas and 65 of 70 positive cases in small cell lung carcinoma, than in carcinoids with 10 of 17 and 2 of 3 positive cases in typical carcinoids and atypical carcinoids, respectively. The neural cell adhesion molecule-polysialic acid form scores of staining were significantly higher in high-grade as compared with low-grade tumors (p = 0.002), and were correlated with nodal spread (p = 0.04) and metastasis (p = 0.016) across histologic classes but not in individual tumor type. We conclude that NCAM-PSA connotes poor differentiation and aggressive clinical behavior in the spectrum of NE lung tumors, but cannot be regarded as a prognostic factor in individual tumor classes.

Cyclin D1 and human neoplasia

Neoplasia is characterised by abnormal regulation of the cell cycle. Cyclin D1 is a protein derived from the PRAD1, CCND1 or bcl-1 gene on chromosome 11q13, which is involved in both normal regulation of the cell cycle and neoplasia. In the G1 (resting) phase of the cell cycle, cyclin D1 together with its cyclin dependent kinase (cdk) partner, is responsible for transition to the S (DNA synthesis) phase by phosphorylating the product of the retinoblastoma gene (pRB), which then releases transcription factors important in the initiation of DNA replication. Amplification of the CCND1 gene or overexpression of the cyclin D1 protein releases a cell from its normal controls and causes transformation to a malignant phenotype. Analysis of these changes provides important diagnostic information in mantle cell (and related) lymphomas, and is of prognostic value in many cancers. Knowledge of cyclin D1's role in malignancy at the various sites, provides a basis on which future treatment directed against this molecule can proceed.

Prognostic factors in resected non-small cell lung cancer: an immunohistochemical study of 39 cases

Non-small cell lung carcinoma (NSCLC) is a histologically heterogeneous collection of tumours with variable clinical behaviour. Performance status, tumour stage and histological type have important prognostic implications, but the clinical outcome in an individual patient remains unpredictable. In search of other prognostic factors we studied the expression of several immunohistochemical markers in NSCLC, resected with curative intent. Tumour samples of 19 patients with a postoperative disease-free survival of at least 5 years and those of 20 patients who died of tumour recurrence within 2 years after resection were selected for this study. The populations were matched for age, sex and tumour stage. We investigated the expression of markers for neuroendocrine differentiation, cell adhesion and cell cycle regulation in both populations. None of the investigated immunohistochemical markers distinguished between long- and short-term survivors of resected NSCLC. In stage 1 tumours expression of embryonal NCAM was observed more often in the short survival group (P = 0.026) and in stage 3a EGF-r expression was associated with the long survival group (P = 0.047). However, these findings remained to be confirmed. Expression of Rb, NCAM and embryonal NCAM was not detected in adenocarcinomas, whereas T-Ag and chromogranin A immunoreactivity was absent from squamous cell carcinomas.