S-1-containing chemotherapy for patients with non-small-cell lung cancer: A population-based observational study by the Ibaraki thoracic integrative (POSITIVE) research group.

To evaluate the efficacy and safety of S-1 monotherapy, S-1-containing combined chemotherapy and S-1 containing chemoradiotherapy for non-small cell lung cancer (NSCLC), a population-based observational study was performed. The efficacy and safety of the chemotherapies were evaluated at 13 institutes in a prefecture of Japan between April 2011 and March 2015. Datasets were obtained from 282 patients with NSCLC. For either wild-type or mutated epidermal growth factor receptor (EGFR), these three therapy groups generated almost identical response results and toxicity profiles as those in previously reported clinical trials, although the present study appeared to have slightly lower survival rates compared with those in the previous clinical trials. This may be due to the inclusion of patients in poor condition, and S-1 therapy being administered in the second, or later, line of therapy. In conclusion, the present study has confirmed that S-1-containing chemotherapy is effective against wild- and mutated-type EGFR NSCLC, and it is also tolerable in clinical practice.