Multiple myeloma index: verification of a new prognostic approach with evaluation of treatment response

Currently adopted prognostic criteria for multiple myeloma (MM) still lack reliable predictive ability to select subsets of patients for different therapies, in particular for intensive treatment protocols. In this work we aimed to test the prognostic value of the MM Prognostic Index (MMPI), developed in 1996 by Grignani et al. from Pavia University as a clinical and investigational tool.

Ninety-three MM patients were eligible for the study. All received initial induction therapy based on a standard 6-month melphalan + prednisone (M + P) protocol. Clinical and laboratory parameters, conventional staging and bone marrow infiltration percentage and cytopathology (BMIC) were assessed at diagnosis, while treatment response (TR) was evaluated using criteria after induction therapy. Cox's multivariate survival analysis was applied on prognostic data.

In our patients independent prognostic value was confirmed for British Medical Research Council staging, BMIC and TR, the three factors considered in MMPI. Risk classes obtained via MMPI identify patients with different outcomes; moreover, the index discriminates significantly among Stage II patients.

This new approach to MM prognosis is simple and reliable from the prognostic point of view; it refers not only to neoplastic mass, but also to intrinsic proliferative capacity of the malignant clone and to tumor-host interactions. We recommend its adoption in clinical practice and in the evaluation and design of therapeutic trials.