Tools used in the diagnosis and staging of lung cancer: what's old and what's new?

Abstract

Lung cancer is the most common cause of cancer related death in the world. In the UK in 2005, there were around 39 000 new cases of lung cancer and 34 000 deaths due to the condition (http://info.cancerresearchuk.org). Moreover, within the UK, rates of lung cancer in Scotland—especially within urban areas—are far higher than in other areas. While lung cancer incidence in men is falling in the UK, more women are being diagnosed due to increased cigarette smoking. Over the years, new tools such as positron emission tomography/computed tomography (PET/CT), transbronchial needle aspiration (TBNA), endobronchial ultrasound (EBUS), oesophageal ultrasound and medical thoracoscopy have been introduced and many studies have evaluated where they may become suitably placed in lung cancer diagnostic and staging algorithms. This evidence-based review provides the reader with an update of current and recently developed strategies in the diagnosis and staging of lung cancer. All authors performed a comprehensive search of articles published up to September 2008 using Pubmed and Medline. Keywords and phrases used were lung cancer, diagnosis, staging, investigations, endobronchial ultrasound, lymph node metastasis, positron emission tomography, PET/CT, transbronchial needle aspiration, mediastinum, mediastinal lymphadenopathy, survival rates, computerized tomography, bronchoscopy, pleural biopsy. Lung cancer is divided histologically into non-small cell (NCSLC) and small cell (SCLC). NSCLC accounts for ∼80% of all lung cancer and includes a number of pathological subtypes (mostly adenocarcinoma, squamous cell and large cell); SCLC accounts for the remainder. Currently, NSCLC is staged using the TNM system (revised in 1997), based on tumour size (T1-4), lymph node involvement (N1–3) and presence of metastasis (M0–1). Compared with NSCLC, SCLC has a greater tendency to be widely disseminated at the time of presentation and a two-stage system is employed. Limited stage SCLC means tumour is confined to the hemithorax of origin including the mediastinum and supraclavicular … Address correspondence to: G.P. Currie, Aberdeen Royal Infirmary, Aberdeen AB25 2ZN, Scotland, UK. email: graeme.currie{at}nhs.net