Potential Influence on Clinical Trials of Long-Term Survivors of Stage IV Non-small cell Lung Cancer

Background: New, effective treatments have resulted in long-term survival for small subgroups of metastatic non-small cell lung cancer (NSCLC) patients. However, knowledge of long-term survivor frequency and characteristics prior to modern therapies is lacking. Methods: Surveillance Epidemiology and End Results (SEER) patients with stage IV NSCLC diagnosed from 1991 to 2007 and followed through 2012 were dichotomized by survival time into the 10% who lived 21 months or longer (long-term survivors) vs the remaining 90% and compared with participants in a representative clinical trial of molecular profiling and targeted therapies (CUSTOM). Results: Among the 44 387 SEER patients, the 10% identified as long-term survivors were distinguishable from the remaining 90% by younger age, female sex, Asian race, adenocarcinoma histology, tumor grade, tumor site, and surgery. From 1991–1994 to 2003–2007, median survival increased by 6 months from 30 to 36 months among long-term survivors but by only 1 month from 3 to 4 months among the remaining 90%. Among the 165 participants in the CUSTOM trial, 54% met our SEER criterion of long-term survival by living for 21 months or longer. Conclusions: Among SEER patients with stage IV NSCLC, long-term survivors had a median survival approximately 10 times that of the remaining 90%. Long-term survivors accounted for more than one-half of the participants in a representative clinical trial. Caution is required when extrapolating the outcomes of participants in clinical trials to patients in routine clinical practice.