Elevated levels of soluble PD-L1 (sPD-L1) have been associated with worse prognosis in renal cell carcinoma and multiple myeloma. However, the regulatory roles and function of sPD-L1 in advanced melanoma are not fully understood. This study was designed to evaluate the association between circulating sPD-L1 expression and prognosis in patients with advanced acral and mucosal melanoma.
Totally 102 untreated advanced acral and mucosal melanoma patients from Peking University Cancer Hospital between Jan 2012 and Dec 2015 were enrolled in the present study. Peripheral blood samples were obtained from 40 healthy donors as control. Circulating sPD-L1 expression was tested by enzymelinked immunosorbent assay (ELISA).
The advanced melanoma cohort includes 58 acral melanoma and 44 mucosal melanoma. Concentrations of sPD-L1 (2.91ng/mL) were elevated in the plasma of prior to treatment advanced melanoma patients in comparison with healthy donors (0.59ng/mL). The expression of sPD-L1 in serum was found to be highly up-regulated in 39 (38.2%) of 102 cases. The sPD-L1 concentration appeared to be significantly related with subtype (arcal 3.14 vs. mucosal 2.60 ng/mL P = 0.004). No significant association was observed between serum sPD-L1 level and other clinicopathological variables as: BRAF mutation, LDH level, tumor burden and peripheral blood CD4+/CD8+. There were no associations between sPD-L1 and chemotherapy clinical responses in our cohort. But the overall survival rates were statistically estimated with the expression of sPD-L1. The OS in this cohort with high and low up-regulated sPD-L1 expression levels was 8.50 months and 11.64 months, respectively (p = 0.022).
sPD-L1 was elevated in advance acral and mucosal melanoma patients and may play an important role in patients prognosis.
Clinical trial identification
Legal entity responsible for the study
Peking University Cancer Hospital & Research Institute.
Has not received any funding.
All authors have declared no conflicts of interest.