EP1.12-07 High Discrepancy of Chemotherapy Outcomes Between Patients with Peripheral and Central Small Cell Lung Cancer

Abstract

Previously we found that imaging central and peripheral LCNEC has distinct clinicopathologic features and survival. As LCNEC and SCLC are all neuroendocrine tumor, this study further investigated whether imaging tumor location impact the outcome of first line chemotherapy in patients with small cell lung cancer extensive disease. Patients with ES-SCLC diagnosis between May 2014 and September 2015 in Shanghai Pulmonary Hospital, Tongji University were included. Contrast enhanced CT scans were reviewed retrospectively for tumor location (central or peripheral) and imaging features. The clinical characteristics and outcomes of chemotherapy were collected and compared. 140 patients were identified with a median age of 64, 89.3%, 76.4% and 98.6% were male, smokers and ECOG PS 1 respectively. Among them, 135 received etopside based chemotherapy and 5 received irinotecan based chemotherapy.111 (79.3%) had central-type and 29 (20.7%) had peripheral-type SCLC. The patients characteristics were similar between the central and peripheral subgroups. Peripheral subgroup showed less marginal GGO (65.5% vs 84.7%, p=0.02), obstructive pneumonia (48.3% vs 80.2%, p=0.001), obstructive atelectasis (3.4% vs 40.5%, p<0.001) and effusion (37.9% vs 61.3%, p=0.011) than central tumors. Peripheral subgroup had lower ORR (44.8% vs 73%, p=0.004) and DCR (79.3% vs 92.8%, p=0.042). The median PFS was 4.6 months in the entire cohort and peripheral subgroup had significantly short PFS than central one (median PFS: 3.4 vs 5.1 months, p=0.001, figure A). The median OS was 12.9 months and peripheral subgroup had numerally short OS (median 11.6 vs 13.3 months, p=0.266, figure B). Central type tumors account for most of SCLC, while patients with peripheral tumors had a significantly lower ORR, shorter PFS and OS after the first line chemotherapy than central type.