Survival of Patients With Primary Cutaneous Melanoma and the Surgical Treatment Option Based on the Level of the Surface Protein PD-L1 in the Tumor Tissue

Abstract

Background: The PD-­L1 level is mainly used to predict the effect of drug treatment in patients with melanoma. Despite the radical nature of surgery in these patients, the rate of disease progression remains high. Therefore, it is important to study the relation between the PD-­L1 level in the tumor and surgical treatment options for cutaneous melanoma and patient survival.Objective: To analyze the effect of the PD-­L1 level in patients with primary cutaneous melanoma at different levels of tumor excision and options for closing the surgical defect.Materials and methods: We used data of 143 patients with stage 0­IIIC primary cutaneous melanoma who were randomized into 2 groups: the main group (wide excision of the tumor and plastic repair of the tissue defect) and the comparison group (standard tumor removal) with different PD-­L1 levels (IC [immune cells] %). The 5­-year survival of patients was estimated.Results: We found the mutual dependence of the PD­-L1 level and the survival of patients with stage 0-­IIC melanoma on the extent of the tissues removed and the option for closing the defect.Conclusions: The 5­year progression­free survival in patients with stage 0­IIA primary cutaneous melanoma was higher than that of those with stage IIB-­IIC melanoma regardless of the PD-­L1 level. In patients with stage 0-­IIA primary cutaneous melanoma and the low PD-­L1 level (˂5), progression­free survival was 26.3% higher (P = .013) than that of those with the high PD-­L1 level (≥5). In patients from the main group with stage 0-­IIA melanoma and the low PD­L1 level (˂5), progression­free survival was 25% higher (P = .017) and overall survival was 16.7% higher (P = .045) compared with patients from the control group with the same PD-­L1 level. In patients from the main group with stage 0­-IIC melanoma and the high PD­-L1 level (≥5), the 5-­year progression­free survival was 21.2% higher (P = .033) compared with patients from the comparison group.