Outcomes in recurrent small-cell lung cancer after one to four chemotherapy lines: a retrospective study of 300 patients

Abstract

Standard treatment of small-cell lung cancer (SCLC) is a combination of etoposide and platinum for patients with extensive disease, associated with radiotherapy for patients with limited disease (LD). Therapeutic strategies for relapse, although well characterized, are disappointing. Between 1997 and 2009, 300 patients were treated for SCLC at Grenoble University Hospital. We analyzed patients' characteristics and outcomes at different treatment steps, to determine prognostic factors and propose subsequent treatment strategies according to "sensitive", "resistant" or "refractory" status established after first-line treatment (L1). The median patient age was 63.2 years, 46.3% had LD, and 23% were female. The objective response rate (ORR) to first-line chemotherapy was 73% [CI(95%): 67.6-77.9] and median survival was 13 months. After L1, comparison between "refractory" and "sensitive" groups showed more extensive disease (76.6% vs. 34.3%, p=0.003), poorer Performance Status (PS 0-1: 48.4% vs. 67.8%, p=0.008), more endocrine paraneoplastic syndrome (18.7% vs. 8.4%, p=0.03) and more composite histology (17.2% vs. 4.9%, p=0.004) in "refractory" patients. After second line (L2), ORR was 55.8% [CI(95%): 45.2-66.0] in "sensitive", 18.2% [CI(95%): 8.2-32.7] in "resistant", and 14.7% [CI(95%): 4.9-31.0] in "refractory" groups; with partial response only for the last two groups. After L3 and L4, ORR was 24.0% [CI(95%): 14.9-35.2] in "sensitive", 9.1% [CI(95%): 11.2-29.2] in "resistant" with partial response only. No response was observed for "refractory". After L1, the median survival was respectively 23, 10 and 6.4 months for "sensitive", "resistant" and "refractory" groups (p<0.001). Multivariate analysis showed that LD and classical SCLC histology were positive predictors of belonging to the "sensitive" group. Positive factors for survival were sensitivity to L1, PS 0-1, LD, Charlson score <4, no endocrine paraneoplastic syndrome and no occupational exposure. Limited disease is the major predictive factor for sensitivity to treatments and survival. Factors linked to the patients' clinical presentation also impact on survival. With currently recommended drugs, the "sensitivity" of the patient determined by the response to L1 indicates that it is pointless to treat "sensitive" with L4, "resistant" with L3 and "refractory" with L2, except for a few selected patients after multidisciplinary group discussion.