P1.07-048 Clinical Impact of the Relationship between Post-Progression Survival and Overall Survival in Extensive Disease Small Cell Lung Cancer Patients

Abstract

The effects of first-line chemotherapy on overall survival (OS) might be confounded by subsequent therapies in patients with small-cell lung cancer (SCLC). Therefore, by using individual-level data, we aimed to determine the relationships between progression-free survival (PFS) or post-progression survival (PPS) and OS after first-line chemotherapies in patients with extensive disease SCLC (ED-SCLC) treated with carboplatin plus etoposide. Between July 1998 and December 2014, we analyzed 63 cases of patients with ED-SCLC who were treated with carboplatin and etoposide as first-line chemotherapy. The relationships of PFS and PPS with OS were analyzed at the individual level. Spearman rank correlation analysis and linear regression analysis showed that PPS was strongly correlated with OS (r = 0.90, p < 0.05, R2 = 0.71) and PFS was moderately correlated with OS (r = 0.72, p < 0.05, R2 = 0.62). Type of relapse (refractory/sensitive) and the number of regimens administered after disease progression after the first-line chemotherapy were both significantly associated with PPS (p < 0.05). PPS has a stronger relationship with OS than does PFS in ED-SCLC patients who have received first-line chemotherapy. In addition, type of relapse (refractory/sensitive) after first-line treatment and the number of additional regimens after first-line treatment are significant independent prognostic factors for PPS. These results suggest that treatments administered after first-line chemotherapy affect the OS of ED-SCLC patients treated with carboplatin plus etoposide.