Prognostic Factor Analysis in Patients With Small-Cell Lung Cancer Treated With Third-Line Chemotherapy

There is little information on the clinical outcome of patients with small-cell lung cancer (SCLC) treated with third-line chemotherapy. The purpose of this study was to clarify the prognostic factors of SCLC patients receiving third-line chemotherapy.

Between November 2001 and October 2011, 202 of 648 consecutive SCLC patients at the National Cancer Center Hospital East received third-line chemotherapy. Multivariate Cox regression analysis was performed to identify the prognostic factors for overall survival after third-line chemotherapy.

The demographics of the 202 patients were as follows: median age 66 years, 83% male, and Eastern Cooperative Oncology Group (ECOG) performance status (PS) 0, 1, 2, and 3 values of 22, 122, 49, and 9, respectively. Median time to treatment failure after second-line chemotherapy (TTF2) was 4.5 months (TTF2 ≥ 5/< 5 months, 82/120). The median overall survival after third-line chemotherapy was 5.1 months. Multivariate Cox regression analysis showed that PS 0-1 (hazard ratio, 0.38; 95% confidence interval, 0.27-0.54; P < .001) and TTF2 ≥ 5 months (hazard ratio, 0.57; 95% confidence interval, 0.41-0.79; P < .001) were independent prognostic factors. TTF2 threshold of 5 months was determined on the basis of concordance probability adjusted by PS.

PS 0-1 and TTF2 ≥ 5 months were associated with a favorable prognosis among SCLC patients receiving third-line chemotherapy. These 2 factors might be helpful for the selection of candidates for third-line chemotherapy and for patient stratification when conducting future clinical trials in the third-line setting.