Rechallenge treatment with a platinum-based regimen in patients with sensitive relapsed small-cell lung cancer

Among patients with relapsed small-cell lung cancer (SCLC), those who relapse > 90 days after first-line chemotherapy are classified sensitive relapse. Rechallenge with a first-line platinum-based regimen has been used in sensitive relapsed SCLC patients, but its importance is not known. We evaluated the outcome of rechallenge with platinum-based chemotherapy for sensitive relapse patients. We reviewed consecutive patients with sensitive relapsed SCLC who received second-line chemotherapy between January 1999 and December 2016. We evaluated the treatment outcomes of platinum-based rechallenge and non-rechallenge regimens for second-line chemotherapy in sensitive relapse patients. Of 245 patients, 81 sensitive relapse patients received second-line chemotherapy. Sixty-seven patients (82.7%) were treated with rechallenging platinum-based regimens ("rechallenge group") and 14 patients (17.3%) were treated with other regimens ("non-rechallenge group") as second-line chemotherapy. Median progression-free survival (PFS) was 5.1 months in the rechallenge group and 3.5 months in the non-rechallenge group, and median survival time was 10.8 and 8.2 months, respectively. There were no significant differences in PFS or overall survival (OS) between the two groups. Sub-analyses of patients who received chemotherapy alone as first-line treatment showed that the rechallenge group had longer PFS than that of the non-rechallenge group (median 5.4 vs. 3.6 months, p = 0.0038), and the rechallenge group had a tendency to have longer OS than non-rechallenge group. These data suggest that rechallenge treatment with a platinum-based regimen could be second-line chemotherapy in patients with sensitive relapsed SCLC, especially those treated with chemotherapy alone as first-line therapy.