[The new TNM classification for lung tumors : Changes and the assessment of multiple tumor foci]

[Histology, cytology and molecular diagnostics of lung cancer]

Traditionally, tissue-based histopathological approaches play an outstanding role in the diagnostics of lung cancer. The importance of these methods has become even more important with the introduction of individualized treatment options. Lung cancer is basically classified following the World Health Organization (WHO) guidelines using conventional histology and immunohistochemistry. For individual entities in certain clinical stages, the evaluation of the tumor biological profile serves as the basis for the so-called individualized treatment or precision medicine where changes in the intracellular signal transduction mechanisms are the target of therapeutic efforts or the therapy tries to re-initiate immunogenic reactions of the autologous immune system against the tumor cells. The histopathologic overexpression of receptors as well as various genetic and epigenetic changes (e.g. inversion, translocation and methylation) are the key players for predictive approaches to uncover the individual tumor biology and to make treatment decisions.

Overexpression of 14-3-3ζ in lung tissue predicts an improved outcome in patients with lung adenocarcinoma

One of the factors limiting the survival rate of patients with lung cancer is the high risk for recurrence following surgical resection. Previous studies indicate that 14-3-3ζ is a central cellular hub protein that regulates multiple signaling pathways involved in cancer progression. The present study evaluated the prognostic significance of 14-3-3ζ in patients with lung adenocarcinoma. The expression of 14-3-3ζ and E-cadherin, an important protein involved in the epithelial-mesenchymal transition, was evaluated by immunohistochemistry in lung tumor tissues and adjacent normal lung tissues resected from 123 patients with lung adenocarcinoma. The correlation between the two proteins, their association with clinicopathological features and their prognostic significance were subsequently analyzed. Within these parameters, an overall survival (OS) prediction model was constructed using multivariate Cox proportional hazards regression. The expression of 14-3-3ζ was upregulated in lung adenocarcinoma, in contrast to E-cadherin, which was downregulated in lung adenocarcinoma tissues compared with normal tissues. In addition, the expression of 14-3-3ζ was positively correlated with that of E-cadherin (r=0.256, P=0.012) and differentiation (P<0.001). Increased E-cadherin expression was indicative of smaller tumor size and greater differentiation, and the overexpression of 14-3-3ζ and E-cadherin were associated with longer OS (P=0.010 and P=0.006, respectively). Finally, a multivariate analysis revealed that TNM stage and 14-3-3ζ were independent prognostic indicators (P<0.001 and P=0.026, respectively). 14-3-3ζ may function as a tumor suppressor associated with E-cadherin upregulation and could be used as a prognostic biomarker for resected lung adenocarcinoma. These findings provide a novel insight on potential intervention strategies for patients with lung cancer.