Gene expression of lung squamous cell carcinoma reflects mode of lymph node involvement.

Tumour, node, metastasis staging is essential for lung cancer management. However, similarly staged cancers may have markedly different prognoses, indicating that stage cannot completely explain tumour behaviour. While ipsilateral hilar node involvement is designated N1, the current authors hypothesised that primary tumours involving nodes by direct extension are biologically distinct from those involving nodes through lymphatic metastasis. Microarrays were used to investigate the gene expression profiles of 59 primary lung squamous cell carcinomas, comparing N0 tumours (n = 35), N1 tumours by direct extension (N1d; n = 8), and N1/N2 tumours by lymphatic metastasis (N1/N2m; n = 16). Hierarchical clustering using 125 genes differentially expressed between N0 and N1/N2m tumours found N1d tumours clustered with N0 tumours. Class prediction modelling found the expression profiles of all eight N1d tumours were more similar to N0 than to N1/N2m tumours. The present study demonstrates for the first time that N1 tumours directly invading hilar nodes are genomically different to those that metastasise via lymphatics. Independent reports suggest that tumours with direct, rather than metastatic node involvement have better outcomes. Consequently, the data suggest that there is a need to re-evaluate the N1 staging definition in lung cancer. This is relevant for prognosis prediction and also for clinical management, particularly in selecting those patients most likely to benefit from adjuvant chemotherapy.

Loss of p16 expression is associated with histological features of melanoma invasion.

While mutations of CDKN2A are associated with melanoma predisposition, the precise role of its gene product p16 in the development of sporadic melanoma is less clearly understood. We sought to determine the prevalence of p16 expression using immunohistochemical analysis in a population-based sample of melanoma tumours, and also to identify histological, phenotypic and environmental factors associated with the presence or absence of p16 expression. We conducted face-to-face interviews with 108 patients newly diagnosed with melanoma to ascertain their history of sun exposure, and recorded various phenotypic parameters. Paraffin sections of tumours from these patients were stained with an anti-p16 monoclonal antibody following antigen retrieval. Overall, 52 (48%) tumours expressed p16; nodular melanomas had significantly lower levels of p16 immunoreactivity than superficial spreading melanomas (P = 0.015). While no association was found between p16 expression and host phenotype, loss of p16 staining was associated with thicker lesions (p = 0.084) and a high mitotic index (P = 0.013). Taken together, these findings are consistent with loss of p16 being a late event in the progression of sporadic primary melanomas, being associated with tumours of a more aggressive nature.

Impact of the fibrinolytic enzyme system on prognosis and survival associated with non-small cell lung carcinoma.

Comprehensive studies of fibrinolysis in non-small cell lung carcinoma have been limited, and assignment of patients to high/low prognosis groups based on arbitrary cut-offs utilizing fibrinolytic measurements is unstandardized. This study was performed in 166 patients to examine the effects of cut-off values determined in three ways. Model 1 assigned patients to one of three equal groups (low, medium, high) based on fibrinolytic measurements made at diagnosis, Model 2 divided patients into low/high groups using median values, and Model 3 grouped according to the parameter being above/below normal range. In model 1, raised plasma fibrinogen, D-dimer and soluble fibrin were positively associated with poorer survival. In model 2, tissue plasminogen activator antigen was additionally related to poorer prognosis. Model 3 identified seven parameters as significantly related to survival, two not identified by the other models becoming significant [plasmin-antiplasmin, tissue plasminogen activator inhibitor-1 (PAI-1) antigen]. Using multivariate analysis, plasma fibrinogen level was the most uniformly significant parameter. Relative risk estimates indicated that raised plasma fibrinogen, soluble fibrin and D-dimer were associated with increased risk of death. Use of the normal/above normal cut-off is recommended to provide the maximum number of significant parameters relating to prognosis, and increased plasma D-dimer, PAI-1 antigen and fibrinogen were most closely related to survival/prognosis.

Alterations to the fibrinolytic enzyme system in patients with non-small cell lung carcinoma.

Although fibrinolysis has been implicated in the progression and metastasis of lung cancer, no detailed study has been carried out on components measured in samples from both plasma and tumour. This study thus provides the first comprehensive data obtained from 166 patients diagnosed with non-small cell lung carcinoma. Plasma samples were obtained at diagnosis and tumour samples during surgical resection. Appropriate control samples were obtained from normal subjects and patients with chronic obstructive airways disease (plasma) and from organ donors (normal lung tissue). Assays were performed on plasma and tissue extracts for tissue plasminogen activator, urokinase-like activator and plasminogen activator inhibitor (activity and antigen in all cases), together with plasmin-antiplasmin complex, soluble fibrin, D-dimer and thrombin-antithrombin complex. Levels of D-dimer, thrombin-antithrombin complex and plasmin-antiplasmin complex were all significantly higher in plasma from patients, whereas urokinase-like activator activity was reduced. Only two parameters were significantly altered in both the core and periphery of tumour tissue: levels of D-dimer were increased and tissue-type plasminogen activator activity was reduced. Interestingly, significant differences in levels of other fibrinolytic parameters were detected in the core and periphery of tumours. Significant activation of fibrinolysis was indicated in patients, although the origin of this could not be related consistently to changes in levels of plasminogen activator and inhibitor.

Changes in plasminogen activator inhibitor-1 levels in non-small cell lung cancer.

Increased urokinase plasminogen activator (uPA) levels are increased in a number of malignancies and have been correlated with decreased disease-free interval and decreased overall survival. We have, therefore, examined components of this plasminogen activating system in patients with Non-Small Cell Lung Cancer (NSCLC). Levels of uPA, urokinase-plasminogen activator receptor (uPAR) and plasminogen activator inhibitor-1 (PAI-1) were measured semiquantitatively in paraffin sections of tumours from 147 patients with NSCLC. Immunohistochemically stained sections of tumour were allocated a score for stain intensity and results correlated to: survival; tumour stage(T); nodal stage(N); stage grouping (I to IIIb), survival status and sex. Increased levels of PAI-1 were associated with a decreased survival in squamous cell carcinoma (SCC) X2 = 5.72, p = 0.017 (n = 74). There was a significant positive relationship between PAI-1 levels and N-stage (p = < 0.05), presence of nodal metastases (p = < 0.05), stage grouping (p = < 0.01) and extent of disease (p = < 0.05) in the total group and the SCC subgroup, but not adenocarcinoma. There was a significant positive relationship between PAI-1 levels and T-stage (p = < 0.05) in the total group, and survival status (p = < 0.05) in the SCC subgroup alone. uPA and uPAR levels were not significantly associated with tumour staging or survival. We conclude that increased PAI-1 antigen levels may be associated with a decreased survival in patients with SCC.