Malignancy: Identification of Predictors of Disease Status and Progression in Patients with Myeloma (MM)

Multiple studies have attempted to recognize the best markers of disease activity and outcome in myeloma (MM). Our objective was to identify the best variables that can reflect MM disease status. Design and methods: The data obtained from all the following tests were included in the analysis: serum levels of the 2 growth factors known to be crucial for MM growth (i.e. IL-6, and sIL-6R), routine peripheral blood data (Hb%, serum calcium, albumin, CRP, B2m, LDH) and bone marrow plasma cell (BMPC)%, as well as the age and sex of patients. The study was conducted on 21 cases of MM under chemotherapy (aged 48-74 years; M/F = 13/8) and 12 matched normal individuals. The patients were categorized into 2 groups according to their clinical status: Group#1 (n = 16; cases in plateau/stable phase), and Group#2 (n = 5; advanced/refractory cases). Results: Student t-test confirms that serum IL-6 and sIL-6R are the most statistically different variables upon comparing cases in plateau phase (Group#1) with those of advanced disease (Group#2). Stepwise discriminant analysis of data has resulted in a function that is composed of the 2 most salient variables (i.e. serum IL-6, sIL-6R). The proposed function was highly significant (p = 0.0000) with Wilk's Lambda = 0.02538. The diagnostic capability of the proposed function was very high (percent of grouped cases that were classified correctly= 100%). Conclusion: measurement of serum IL-6 and sIL-6R gives the best prediction of disease activity in patients with MM.