Staging and clinical prognostic factors for small-cell lung cancer.

The two-stage system introduced by the Veterans' Affairs Lung Study Group continues to be widely utilized in small-cell lung cancer (SCLC), mainly because of its simplicity and clinical utility. Approximately one third of patients with SCLC present with limited-stage disease, which is defined as disease that can be encompassed in a tolerable radiation field. However, this definition is controversial when it is applied to the staging classification of patients with locoregionally advanced disease manifested as the presence of an ipsilateral pleural effusion, contralateral supraclavicular lymphadenopathy, or contralateral mediastinal lymphadenopathy. The more descriptive TNM system is useful for patients with disease limited to the lung, when surgical resection may be feasible; this occurs in far less than 10% of cases. As shown by clinical studies and autopsy data, metastatic disease frequently involves the liver, adrenals, bone, bone marrow, and brain. History and physical examination, complete blood count and chemistry studies, chest x-ray studies, computed tomography of the chest or upper abdomen, computed tomographic scanning or magnetic resonance imaging of the brain, and bone scans are recommended for the pretreatment evaluation of patients with SCLC. A bone marrow biopsy may be omitted for patients with normal blood counts, normal lactate dehydrogenase level, and negative result on bone scan. The use of new imaging modalities, such as magnetic resonance imaging of the bone marrow and positron emission tomographic scanning, may optimize staging evaluation. Multiple prognostic parameters have been identified for patients with SCLC, the most important of which are the stage or extent of disease, performance status, serum lactate dehydrogenase level, and male gender. Identification of risk factors for treatment-related mortality is important for the management of patients with SCLC.