Prognostic and clinicopathological significance of SR-B1 in solid tumors: A meta-analysis

The expression of cell surface receptors is abnormal in malignant tumors. The scavenger receptor class B type I (SR-B1) is an integral membrane glycoprotein receptor that facilitates the selective uptake of cholesterol by malignant cells. Accumulated studies investigated the prognostic role of SR-B1 in many solid tumors, such as breast cancer, lung cancer and so on. However, the conclusions remain undefined. Therefore, we conducted this meta-analysis to obtain more accurate evaluation of prognostic significance of SR-B1 in solid tumors.

We searched PubMed, Embase, Web of science and Cochrane library for eligible studies published before November 2018. The included studies investigated the association between the SR-B1 level and clinicopathological features including survival outcomes in solid tumors. Hazard ratios (HRs) with 95% confidence intervals (CIs) were adopted to assess the survival outcomes and odds ratio (ORs) with 95% confidence intervals (CIs) were pooled to evaluated the clinicopathological features.

A total of 10 studies involving 2585 patients were included in this meta-analysis. The results showed that low SR-B1 level was significantly correlated with earlier tumor grade (pooled OR = 2.09, 95%CI = 1.28-3.43, P = 0.001), less nodal involvement (pooled OR = 2.07, 95%CI = 1.43-3.0, P < 0.001), less distant metastasis (OR = 19.8, 95%CI = 2.58-151.65, P = 0.004), smaller tumor size (OR = 2.34, 95%CI = 1.53-3.57, P < 0.001), earlier TNM stage (OR = 3.77, 95%CI = 1.67-8.48, P = 0.001), lower recurrence (HR = 1.98, 95%CI = 1.57-2.49, P = 0.000), and better OS (HR = 1.99, 95%CI = 1.70-2.31, P = 0.000).

The low expression of SR-B1 was significantly associated with better clinicopathological status and longer survival in patients with solid tumors. SR-B1 might act as a promising prognostic biomarker for solid tumors.