Significance of increased neutrophils in patients with advanced colorectal cancer.

We examined the ratio of neutrophils to lymphocytes (N/L ratio) in the peripheral blood in patients with colorectal cancer. The ability to produce active oxygen and phagocytosis of neutrophils, G-CSF, sIL-2R and IAP (immunosuppressive acidic protein) were also measured. The N/L ratios were significantly higher in the advanced stages of cancer than in normal controls. The ability to produce active oxygen in the terminal stage was 33% lower than in the control group. The G-CSF levels had no relationship with the neutrophil counts. IAP levels increased with cancer stage, and were inversely related to the ability to produce active oxygen. The IAP levels correlated well with the sIL-2R levels and the N/L ratio. These findings suggest that the ability to produce active oxygen, N/L ratio and IAP reflect anticancer mechanisms and that they may be useful when considering treatment or prognosis of patients with advanced stages of cancer.