Prognostic value of the staging system proposed by Merlini, Waldenström and Jayakar for multiple myeloma

We have reviewed a series of 90 consecutive patients with multiple myeloma (MM) diagnosed in the period 1.1.1971-31.12.1980 and subsequently treated with an intermittent administration of melphalan and prednisone (62 IgG MM, 20 IgA MM and 8 Bence-Jones (BJ) MM). Unfavorable prognostic factors were: presence of micromolecular M component (K or lambda), serum creatinine greater than or equal to 2 mg/dl, serum calcium greater than or equal to 12 mg/dl, presence of BJ proteinuria, Hb less than 10 g/dl, diffuse osteolytic lesions, bone marrow plasma cell percentage greater than or equal to 30%. In particular, according to the recent staging system proposed by Merlini et al. [Blood 55: 1011, 1980], the most important prognostic parameters for IgG and BJ MM were: serum creatinine, BMPC % and serum calcium; for IgA MM the most important were: serum hemoglobin, calcium and M component levels. We have compared the survival curve of 45 patients who died, with the predicted survival curve according to the multivariate regression analysis of Merlini and co-workers; the prediction was equally precise for all the three types of MM considered, thus showing the high sensibility of this new staging system.