The classification of small cell lung tumors is much simpler. In this type of cancer is spoken of limited stage and extensive stage.

The limited stage means that the tumor is confined to the hemithorax of origin, the mediastinum and supraclavicular nodes. This would be tolerable in the employment field of radiotherapy.

The extended period is one in which the cancer is too widespread to be included within the definition of limited stage, ie the cancer has spread to other lung, to lymph nodes in the other breast to distant organs, and so on.

Patients with limited stage of cancer may be effectively treated with radiation therapy. In those with extensive stage is not as applicable radiotherapy.