In small cell lung cancer (SCLC), chemotherapy is typically the primary treatment due to its high initial responsiveness and the potential for rapid spread beyond the lungs. This makes chemotherapy the preferred choice in almost all SCLC cases, even if there are no signs of spread on CT scans.

For limited-stage SCLC, chemotherapy options may include chemotherapy following surgery or chemotherapy combined with radiation therapy post-surgery.

In extensive-stage SCLC, treatment options may involve combination chemotherapy or a combination of chemotherapy and immunotherapy. In some cases, chemotherapy may be followed by radiation therapy.