What is early lung cancer? A review of the literature.

The dismal cure rate of patients with lung cancer and the stage shift hypothesis have propelled the interest to perform screening at large, despite that previous randomized clinical trials failed to show any mortality benefit and the controversial issue of overdiagnosis. Due to early detection programs, a larger number of individuals at risk will be found to harbor small and potentially malignant early stage lesions. The application of non- and minimal invasive techniques for early detection, staging and treatment will become increasingly important. This review deals with the available clinical, surgical and pathological data focusing on early lung cancer lesions < or =1 cm. Literature data from both centrally located and parenchymal lesions < or =3 cm. have been analyzed. For all sub-centimeter lesions, minimal invasive staging and treatment approaches must still be considered inappropriate. Less invasive and less extensive treatment methods may be considered in high risk individuals with < or =1 cm. peripheral lesion showing > or =50 ground glass opacity on high resolution CT scan and those with superficial lesion in their central airways without deeper tumor invasion in the bronchial wall. Caution is necessary, however, as clinical staging remains inferior to pathological staging which is based on tissue samples collected after complete tumor removal and mediastinal lymph nodes dissection have been performed.