Neoadjuvant intra-arterial chemoembolization improves tumor pathological regression and survival in Borrmann type IV gastric cancer

Figure 5 Schematic illustration of the tumor microenvironment remodeling induced by neoadjuvant intra-arterial chemoembolization in Borrmann type IV gastric cancer. A: Pre-treatment immunosuppressive “cold” microenvironment. The tumor is characterized by an abundance of fibroblasts and a dense desmoplastic stroma, which acts as a formidable physical barrier preventing the infiltration of cytotoxic immune cells, such as CD8+ T cells and natural killer cells, restricting them to the tumor periphery; B: Post-treatment inflamed “hot” microenvironment. The localized, high-concentration delivery of oxaliplatin combined with lipiodol-induced embolic ischemia effectively disrupts the stromal barrier. This dual mechanism triggers massive immunogenic cell death and necrosis of the cancer cells, subsequently facilitating the robust, deep infiltration of CD8+ T cells and natural killer cells into the tumor core. NK: Natural killer.