Circulating immune complexes in patients with benign and malignant colorectal tumours

Circulating immune complexes were measured using a modified Clq binding assay in 100 preoperative patients with colorectal cancer and in 52 patients with benign polyps. Sixty-one per cent of the patients with cancer and 49 per cent of the patients with benign polyps had elevated levels, as did 92 per cent of those with malignant polyps. There was no relation to a, the stage of the disease, with 10 out of 13 Dukes' A tumours (77 per cent) having increased levels; b, the degree of differentiation of the cancers; c, the tumour mass. However, cancers on the right side of the colon had significantly higher levels than rectal cancers.