Metastatic Lung Small Cell Carcinoma

This phase II trial studies the effects of temozolomide and atezolizumab as second or third line treatment for patients with small cell lung cancer that has spread to other places in the body (metastatic) or has come back (recurrent). Chemotherapy drugs, such as temozolomide, work in different ways to stop the growth of tumor cells, either by killing the cells, by stopping them from dividing, or by stopping them from spreading. Immunotherapy with monoclonal antibodies, such as atezolizumab, may help the body's immune system attack the cancer, and may interfere with the ability of tumor cells to grow and spread. Giving temozolomide and atezolizumab as second or third line treatment may help prolong survival in patients with small cell lung cancer.