Regulatory T cells in lung adenocarcinoma: Mechanisms of immune escape, prognostic significance and therapeutic opportunities (Review).

Abstract

Lung adenocarcinoma (LUAD) represents the most prevalent type of lung cancer, accounting for 35‑40% of all lung cancer cases. Regulatory T cells (Tregs), a CD4⁺ T cell subtype with immunosuppressive functions, play a pivotal role in maintaining self‑tolerance under physiological conditions. Recent evidence has increasingly highlighted their involvement in various cancers. In LUAD, Treg infiltration into tissues undermines the immune anticancer response, correlating with disease stage, treatment efficacy and prognosis. By inhibiting robust anti‑tumor immune mechanisms, Tregs facilitate tumor immune escape in LUAD. Furthermore, elevated Treg cell accumulation in LUAD has been linked to reduced overall survival rates. Tregs serve as independent predictors for LUAD diagnosis in patients at high risk of recurrence. Systematic depletion of all Tregs to enhance anticancer efficacy poses risks of inducing severe autoimmune pathologies. Consequently, understanding the precise structure of tumor‑infiltrating Tregs is essential for effective targeting of these cells in tumors. Additionally, identifying candidate targets or methods for the specific elimination of tumor‑infiltrating Tregs is necessary for developing efficient and safe combination immunotherapy strategies for LUAD. The present study focuses on the regulatory role of Tregs in LUAD prognosis, immune escape and targeted therapies, elucidating the molecular mechanisms of Treg involvement and presenting associated therapeutic targets.