The frequency of M-components in sera of patients with solid malignant neoplasms.

The frequency of M-components was studied by agar gel electrophoresis in sera from 807 patients, 467 (57%) females and 340 (43%) males with histologically proven solid malignant neoplasms.M-components were found in the sera of 40 male and 20 female patients. Apart from two known cases of multiple myeloma and one case of Waldenström's macroglobulinaemia, none of the patients were found to be suffering from these diseases. The frequency of M-components increased with age, and this was more evident in males. Twenty-two of 60 patients with M-components did not exhibit abnormalities on immunoelectrophoresis. Of the 35 remaining patients, 27 had an abnormal component of the IgG class, 6 of the IgA and 2 of the IgM class. M-components were found in the sera of patients with a wide variety of neoplasms. There appeared to be no evidence of an increased frequency of M-components in the sera of patients with solid malignant neoplasms compared with normal adult population.