Serum β2-microglobulin in patients with bronchial carcinoma and controls

Abstract

We measured serum levels of β₂‐microglobulin in 467 patients mainly with suspected pulmonary malignancy. By applying serum concentrations of 3.0 mg/liter as the normal upper limit, we found elevated levels in 21% of the patients with verified bronchial carcinoma (n = 230) and in 11% of the patients with lung diseases of infectious, inflammatory, or other origins but without proven malignancy. A rise in serum β₂‐microglobulin levels with advancing age was demonstrated in cancer patients and controls. No significant differences in serum concentrations were seen between cancer patients subgrouped according to the WHO classification. Serial measurements on cancer patients generally revealed increasing serum‐β₂‐microglobulin with time. The most striking elevations during tumor growth were observed in patients with small cell anaplastic or epidermoid carcinoma. After surgical removal of the lung tumor, no decrease of β₂‐microglobulin was found. Patients who at admission had low circulating levels of β₂‐microglobulin ( 3.0 mg/liter. The mechanism behind elevated β₂‐microglobulin in bronchial carcinoma and the variation of this protein during progression of the cancer disease is unknown. One possible interpretation is that levels increase as a consequence of an increased cell turnover in tumor tissue in combination with an enhanced immune response secondary to the malignant process. Cancer 45:780‐785, 1980.