Endostar improved efficacy of concurrent chemoradiotherapy with vinorelbine plus carboplatin in locally advanced lung squamous cell carcinoma patients with high serum Lp(a) concentration.

Background: The role of vascular targeting therapy combined with concurrent chemoradiotherapy (CRT) has produced many inconsistent results in locally advanced non-small-cell lung cancer (NSCLC), especially in lung squamous cell carcinoma (LSCC). Lipoprotein (a) [Lp(a)] may be critical in the development of tumor angiogenesis, and its levels are individualized and determined genetically. This study aimed to determine whether Lp(a) is correlated with effects of recombinant human endostatin (Endostar) combined with concurrent CRT for locally advanced LSCC.

Methods: Patients with locally advanced LSCC from December 2008 to December 2017 were retrospectively analyzed. Patients were divided into two groups: (I) a chemoradiotherapy group (CRT group) which received weekly vinorelbine and carboplatin concurrently with radiotherapy 60Gy, and (II) an Endostar in combination with chemoradiotherapy group (ECRT group) which received Endostar intravenous drip for 1-14 days (every 3 weeks) concurrently with CRT. Fasting venous blood samples for serum Lp(a) in all patients were collected before the treatment. The effect of Endostar was assessed by stratified analysis.

Results: A total of 94 patients were recruited in this study. There were 59 cases in the CRT group and 35 cases in the ECRT group. Overall, the median progression-free survival (PFS) was 9.6 vs. 14.2 months (P=0.0671), and the overall survival (OS) was 15.0 vs. 20.6 months (P=0.114), in the CRT and ECRT groups respectively. The median of Lp(a) was 218 mg/L. In patients with serum Lp(a) less than 218 mg/L, the median PFS was 10.0 vs. 9.4 months (P=0.406), and the OS was 15.4 vs. 16.3 months (P=0.958) in the CRT and ECRT groups, respectively. However, in patients with serum Lp(a) higher than 218mg/L, the median PFS was 9.0 vs.15.8 months (P=0.011), and the OS was 14.0 vs. 21.1 months (P=0.055), in the CRT and ECRT groups, respectively. Cox proportional hazard model analysis revealed that a high concentration of Lp(a), ≥218 mg/L, is a prognostic factor for PFS [hazard rate (HR), 0.43 (0.23-0.81)] and OS [HR, 0.52 (0.27-0.98)] in locally advanced LSCC (P<0.05).

Conclusions: The serum concentration of Lp(a) may serve as a biomarker to identify the patients who would benefit from Endostar treatment with concurrent CRT in stage III LSCC.