[Circulating immune complex and cancer in the digestive system].

The zone electrophoresis on agarose was used to determine the incidence of circulating immune complex (CIC) in blood of 60 patients with cancer in the digestive system and 42 healthy donors. The correlation between cancer and CIC was investigated. The positive results is 75% in patients and 14.2% in the control. There is a significant correlation between the CIC and the stage of lesion. Higher incidence was observed in patients with stage I and II lesions (100% and 85%) than those with stage III lesions (40%). Among 13 positive patients, 5 with stage I lesion became negative and 8 with stage II or III lesions were still positive after operation. These data suggest that the zone electrophoresis be a reliable assay for the diagnosis and prognosis of patients with digestive system cancer. To measure the CIC periodically may be useful for the follow up of the tumor condition before and after treatment.