7.3 Stages of Lung Cancer: The Diagnostic Approach to Staging NSCLC
7.3 The Diagnostic Approach to Staging NSCLC
It is now accepted that the management of lung cancer includes the detection and histopathological confirmation and classification of lung cancer and the accurate staging systems of the extent of the tumor. These factors will then allow for the appropriate management of patients to be implemented, with the participation of a multidisciplinary team (MDT) of clinicians.
Biopsy of the lung, lymph node, or distant organ (metastases) should aim to provide enough material for an accurate histopathologic, immunohistochemical, and molecular assessment (see Section 6).
Patients with suspected lung cancer will undergo CT of the chest, liver, and adrenal glands (contrast-enhanced) prior to biopsy. In some cases, whole body positron emission tomography (PET) or integrated PET/CT will be performed in those patients with operable lung cancer (clinical stage IB to IIIA disease) to detect lymph node or distant metastases.
A Summary of the Stages of Lung Cancer
For suspected stage IA (T1N0M0) lung cancer: Indeed, patients with stage IA have peripheral tumors, and so pre-operative invasive staging of the mediastinum may not be necessary. These patients can proceed to surgical resection with intraoperative mediastinal lymph node and tissue sampling.
For suspected stage IB, II, and III lung cancer: Mediastinal lymph node sampling is necessary. In addition, lymph node sampling is important in patients where there are suspicions or confirmation of N2/N3 lymph node involvement (stage IB, stage IIA/B). The methods used for lymph node sampling may include endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) with or without transesophageal endoscopic ultrasound fine needle aspiration (EUS-FNA).
When EBUS-TBNA (+/- EUS-FNA) confirms lung cancer: No further diagnostic or staging work-up is necessary.
When EBUS-TBNA (+/- EUS-FNA) is negative or inconclusive: Mediastinoscopy is usually necessary.
For suspected stage M1a, M1b lung cancer: In patients with distant metastases or supraclavicular lymph node involvement (N3, stage IIIB) tissue sampling of these sites for histology is usually necessary.
For patients with pleural effusion: Thoracocentesis under ultrasound guidance is indicated, and fluid cytology diagnosis is recommended. If cytology is negative or inconclusive, repeat fluid sampling may be necessary before considering thoracoscopic biopsy.
For patients with solid pleural lesions: Thoracoscopic biopsy or image-guided biopsy may be necessary.
For patients with radiologic evidence of large tumor volume infiltrating the mediastinum: Radiologic imaging may be considered to be acceptable for assessment of disease stage.
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