Prognostic factors affecting survival in third-line treatment of advanced non-small cell lung cancer: Retrospective cohort study

Aim: In patients who have reached third-line treatment, survival times are short and response to treatment is poor. However, in some patients, survival times and treatment responses are good despite advanced treatment lines. The present study investigates the prognostic factors that affect survival among patients who have undergone third-line treatment for non-small cell lung cancer (NSCLC). Methods: Among the 1,150 patients who were treated for and followed-up with a diagnosis of NSCLC between January 2008 and December 2015, 102 (8%) who had received third-line treatment were included in this retrospective cohort study. Results: The mean patient age was 56 years (SD: 10.1), and 70.6% were male. The third-line treatment provided a median PFS of 2.36 (range: 1.15–36.1) months and an OS of 4.2 (range: 1.28–38.1) months. Cox hazard-model analyses indicated significant associations between prolonged survival and gender, smoking, non-squamous histology, age below 45 years, the presence of EGFR mutations and the use of EGFR tyrosine kinase inhibitors. Conclusion: The prognosis may be better for some patients who have reached third-line treatments, namely, young patients, females, non-smokers, and those with a non-squamous histology. In these patients, physicians should be alert in terms of driver mutations, such as EGFR mutation.