The impact of attaining a minimal disease state after high-dose melphalan and autologous transplantation for multiple myeloma

Initial studies with high-dose therapy (HDT) in myeloma suggest some benefi cial effects of attaining a complete response (CR); however, the effect on survival is difficult to assess owing to inconsistencies in the definition of response between studies. We have analysed 96 newly diagnosed patients a ged less than 65 years who received HDT and assessed the effect of response on survival using electrophoresis, immunofixation and fluorescent IgH poly merase chain reaction (PCR) to define CR. Patients received induction chemo therapy with C-VAMP (adriamycin, vincristine, methylprednisolone, cyclophos phamide) followed by melphalan 200 mg/m(2) and reinfusion of peripheral bro od stem cells. There was a high response to C-VAMP [CR = 24%, partial respo nse (PR) = 64%], with all but one patient improving the depth of response a fter HDT (CR = 69%, PR = 31%). The progression-free survival (PFS) and over all survival (OS) were excellent at a median of 46.4 months and 72+ months, There was a trend towards an improved PFS in patients with an immunofixati on-negative CR compared with patients with a PR (49.4 months, 41.14 months: P = 0.26), This was not evident when electrophoresis was used to define CR . The method used to define CR did not impact on the overall survival and f luorescent IgH PCR failed to add any additional prognostic information. Thi s study supports the widespread use of the European Bone Marrow Transplanta tion group (EBMT) response criteria and suggests that immunofixation should be performed on an patients who become electrophoresis negative.