The possible mechanism of SII-PNI predicting prognosis are as the followings: firstly, elevated neutrophils significantly inhibit lymphokine-activated killer cell-mediated cytotoxic effects, thereby down-regulating the patient's anti-tumor cell immune response and thus promoting tumor cell proliferation and migration [45, 46]; secondly, platelets promote tumour growth by secreting tumour growth factors such as platelet-derived growth factor (PDGF) and vascular endothelial growth factor (VEGF). Here, VEGFA is linked to neoplasm.