Beta-2-microglobulin as a tumor marker in solid malignancies

Beta-2-microglobulin (β₂-MG) and CF.A were measured in the sera of 186 cancer patients divided into two groups: At diagnosis (D) and at follow-up (F). Four groups of patients at diagnosis (D-I, D-II, D-III and D-IV according to TNM classification) and two at follow-up (in remission. F-R S, and in relapse. F-R P) were considered. All patients had normal serum creatinine and urea concentrations. β₂-MG values in D-l were significantly (p 100 ng/ml revealed β₂-MG values close to those of groups D-I and D-IV. In 10% of patients in stage IV or with CEA > 100 ng/ml β₂-MG was lower than the mean value of the healthy population. From data β₂-MG is probably produced by an aspecific reaction to the tumor and the decrease in advanced stages could express a decreased immunologic response. On the other hand, high serum β₂-MG in the initial stages of the neoplasia may reflect an elevated cell turnover, while low β₂-MG during the final stages may be due to a weak expression of the protein by highly undifferentiated cells.