[Correlation between Pretreatment Serum Apolipoprotein Level and Prognosis of Small Cell Lung Cancer Patients].

Background: Lung cancer is the leading cause of cancer-related death, and small cell lung cancer (SCLC) has a poor prognosis in all types of lung cancer. This study evaluated the relationship between pretreatment serum apolipoprotein levels and prognosis in patients with SCLC, seeks a new index can guide diagnosis and treatment of SCLC.

Methods: This study retrospectively analyzed the clinical data of 122 patients with SCLC. The clinical results of patients with serum apolipoprotein levels within 2 weeks before treatment were collected, including apolipoprotein AI (ApoA-I), apolipoprotein B (ApoB), and the ratio of apolipoprotein B to apolipoprotein AI (ApoB/ApoA-I). Patients' progression-free survival (PFS) and overall survival (OS) are the main outcome indicators. The best critical to determine the index's value by X-tile tool. For survival analysis, Kaplan-Meier method was used for analysis, and Cox regression analysis method was used for single factor analysis and multifactor analysis.

Results: Compared with patients with low ApoA-I levels, patients with high ApoA-I levels (ApoA-I>1.12 g/L) had better OS (21.5 mon vs 12.3 mon, P=0.007) and PFS (7.3 mon vs 5.5 mon, P=0.017). In contrast, patients with higher ApoB/ApoA-I levels had worse median OS than patients with lower ApoB/ApoA-I levels (13.4 mon vs 20.7 mon, P=0.012). Multivariate Cox regression analysis showed that ApoA-I was an independent prognostic factor affecting PFS in SCLC patients (HR=0.67, 95%CI: 0.45-0.99, P=0.043). ApoB/ApoA-I is an independent risk factor for OS in patients with SCLC (HR=1.98, 95%CI: 1.21-3.23, P=0.007).

Conclusions: Serum ApoA-I level and ApoB/ApoA-I level before treatment can be important prognostic factors for SCLC, which is helpful to judge the prognosis of patients.