ABSTRACT

Lung cancers are clinically silent for the majority of time as they theoretically grow from a single malignant cell to a potentially detectable lesion. The vast majority of patients diagnosed with lung cancer are symptomatic at the time of diagnosis. In only about 10% of cases is lung cancer discovered incidentally in an asymptomatic patient, for instance as a solitary pulmonary nodule on a routine chest radiograph. Smoking history, 5 concurrent chronic obstructive pulmonary disease (COPD), 6 and previous exposures to certain environmental and occupational carcinogens, 7 including environmental tobacco smoke, 8 predict a higher risk for bronchogenic carcinoma. Ethnic and racial differences also contribute to the smoking-related risk of lung cancer, with African Americans and native Hawaiians within the USA at higher risk. 9 Local tumor growth, regional extension, metastases, paraneoplastic phenomenon, or a combination of mechanisms may cause tumor-associated symptoms ( Table 8.1 ). There are no characteristics of clinical presentation which absolutely distinguish NSCLC and SCLC.