Reconsidering the Cutoff Value for Sensitive and Refractory Relapses in Extensive-Stage SCLC in the Era of Immunotherapy

Traditionally, relapsed SCLC has been classified as "sensitive" or "refractory" on the basis of cutoff values (60 or 90 d) for the duration between the last chemotherapy and disease progression. Nevertheless, these cutoff values are not derived from rigorous analytical methods, and their applicability to contemporary treatments remains uncertain.