Association between baseline tumor dimensions and survival in advanced non-small cell lung cancer (NSCLC).

Abstract

8046 Background: It is not known to what extent radiographic tumor burden is associated with survival in patients with advanced NSCLC. The purpose of this study is to assess whether baseline tumor dimensions are associated with patient survival in advanced NSCLC. Methods: Data were derived from the Eastern Cooperative Oncology Group (ECOG) 4599 trial of carboplatin-paclitaxel (CP) ± bevacizumab (B) for advanced nonsquamous NSCLC. Associations between the Response Evaluation Criteria in Solid Tumors (RECIST) baseline sum longest diameter (BSLD) and progression-free survival (PFS) and overall survival (OS) were evaluated using univariate and multivariable Cox regression models. Results: 759 of 850 patients (89%) enrolled in E4599 had measurable disease and were included in the analysis. 76% of patients were age < 70 years, 46% were female, and 86% were white. Median number of target lesions was 2; median BSLD was 7.5 cm. In univariate Cox models, BSLD predicted OS (HR 1.41; P<0.001) and had a trend toward association with PFS (HR 1.14; P=0.08). OS was 12.6 months (mos) for BSLD < 7.5 cm, compared to 9.5 mos for BSLD ≥ 7.5 cm. This association persisted across both treatment groups (CP: median OS 11.5 vs 8.5 mos; CP+B: median OS 14.1 vs 10.7 mos), when BSLD was categorized according to quartile (median OS: 13.3, 11.5, 11.6, and 8.3 mos; P<0.001), and in a multivariable model controlling for prognostic factors and the presence and site of extrathoracic disease (OS HR 1.24; P=0.01). Conclusions: Radiographic disease burden, as determined by RECIST BSLD, is associated with survival in the E4599 trial. If validated in other populations, this parameter merits consideration in the stratification of patients for clinical trials and may provide important prognostic information for patients and clinicians.