Levels of alpha 2 macroglobulin can predict bone metastases in prostate cancer

In prostate cancer, we previously reported that a marked decrease of serum alpha 2 macroglobulin (alpha 2M) to less than approximately 50 mg/dl was associated with the presence of bone metastases. In order to investigate the relationship between bone metastases and alpha 2M, we assessed these two parameters in 128 patients with prostatic diseases.66 patients with untreated benign prostatic hypertrophy and 62 with untreated prostate cancer were included in the study. Measurement of alpha 2M concentration was performed by Laser-Nephelometry, prostate-specific antigen (PSA) by EIA.The serum alpha 2M levels in prostate cancer with bone metastases showed a significantly lower level compared with the group without bone metastases (p0.01). Cases with serum alpha 2M levels of less than 50 mg/dl all had bone metastases. Serum alpha 2M levels were inversely related to PSA levels in stage M1b disease.Measurement of serum alpha 2M levels may be useful for the diagnosis and follow up of bone metastases in prostate cancer.