Topotecan is currently the only drug approved in Europe and the United States for the treatment of second line of SCLC when the recovery first line of treatment is considered inappropriate. This raises the problem of knowing when the recovery first line of treatment should be considered appropriate. Secondly, the effectiveness of response to chemotherapy can be predicted based on the response to initial chemotherapy and the time interval after stopping first line treatment. A complete response after initial treatment and a long disease-free interval are predictors of better response to a second-line treatment. There are two groups: the said patients 'sensitive', which correspond to the first-line chemotherapy and who have relapsed at least 90 days after the first-line treatment and a group of so-called patients "Refractory" refers patients who progress in 90 days or patients who have not responded or progressed during first-line treatment. Median survival is very different depending on whether patients with so-called "sensitive" or "refractory".