Increased expression of the EZH2 polycomb group gene in BMI-1-positive neoplastic cells during bronchial carcinogenesis.

Polycomb group (PcG) genes are responsible for maintenance of cellular identity and contribute to regulation of the cell cycle. Recent studies have identified several PcG genes as oncogenes, and a role for PcG proteins in human oncogenesis is suspected. We investigated the expression of BMI-1 and EZH2 PcG oncogenes in human bronchial squamous cell carcinomas (SCCs) and bronchial premalignant precursor lesions (PLs). Whereas normal bronchial epithelium was associated with widespread expression of BMI-1 in resting EZH2-negative cells, neoplastic cells in lung carcinomas displayed altered expression of both BMI-1 and EZH2. Two patterns of abnormal PcG expression were observed: increased expression of BMI-1 in dividing neoplastic cells of PLs and SCCs, and enhanced expression of EZH2 and Ki-67 in BMI-1-positive cells according to severity of the histopathologic stage. We propose that altered expression of BMI1 and EZH2 is an early event that precedes high rates of proliferation in lung cancer. Because PcG complexes are normally involved in the maintenance of cell characteristics, abnormal PcG expression may contribute to loss of cell identity

Exhaled breath analysis for lung cancer

Early diagnosis of lung cancer results in improved survival compared to diagnosis with more advanced disease. Early disease is not reliably indicated by symptoms. Because investigations such as bronchoscopy and needle biopsy have associated risks and substantial costs, they are not suitable for population screening. Hence new easily applicable tests, which can be used to screen individuals at risk, are required. Biomarker testing in exhaled breath samples is a simple, relatively inexpensive, non-invasive approach. Exhaled breath contains volatile and non-volatile organic compounds produced as end-products of metabolic processes and the composition of such compounds varies between healthy subjects and subjects with lung cancer. Many studies have analysed the patterns of these compounds in exhaled breath. In addition studies have also reported that the exhaled breath condensate (EBC) can reveal gene mutations or DNA abnormalities in patients with lung cancer. This review has summarised the scientific evidence demonstrating that lung cancer has distinct chemical profiles in exhaled breath and characteristic genetic changes in EBC. It is not yet possible to accurately identify individuals with lung cancer in at risk populations by any of these techniques. However, analysis of both volatile organic compounds in exhaled breath and of EBC have great potential to become clinically useful diagnostic and screening tools for early stage lung cancer detection

Therapeutic bronchoscopy with immediate effect: Laser, electrocautery, argon plasma coagulation and stents

Minimally invasive diagnostic and therapeutic approaches in medicine have been applied for a more selective and tailored approach to reduce patients' morbidity and mortality. The efficacy of interventional pulmonology for palliation of patients with central airways obstruction has been established and its curative potential for intralesional treatment of early cancer has raised great interest in current screening programmes. This is due to the fact that surgical resection and systemic nodal dissection as the gold standard is relatively morbid and risky, especially when dealing with individuals with limited functional reserves due to smoking-related comorbidities, such as chronic obstructive pulmonary disease. Furthermore, such comorbidities have been proven to harbour early stage lesions of several millimetres in size without involvement of nodal disease that may be amenable to local bronchoscopic treatment. Therefore, the success of minimally invasive strategies for palliation and treatment with curative intent strongly depends on the diligent identification of the various factors in lung cancer management, including full comprehension of the limits and potential of each particular technique. Maximal preservation of quality of life is a prerequisite in successfully dealing with individuals at risk of harbouring asymptomatic early lung cancer, to prevent aggressive surgical diagnostic and therapeutic strategies since overdiagnosis remains an issue that is heavily debated. In the palliative setting of alleviating central airway obstruction, laser resection, electrocautery, argon plasma coagulation and stenting are techniques that can provide immediate relief, in contrast to cryotherapy, brachytherapy and photodynamic therapy with delayed effects. With curative intent, intraluminal techniques that easily coagulate early stage cancer lesions will increase the implementation of interventional pulmonology for benign and relatively benign diseases, as well as early cancer lesions and its precursors at their earliest stage of disease. Copyright © ERS Journals Ltd 2006.Articl