The importance of serum levels of selected biological parameters in the diagnosis, staging and prognosis of multiple myeloma.

The study aimed at evaluating the relation of 7 parameters associated with the internal biological properties of myeloma cells and the bone marrow microenvironment to multiple myeloma (MM) stages, distinguishing its initial/asymptomatic phase from monoclonal gammopathy of undetermined significance (MGUS) and assessing their relation to myeloma prognosis. In the studied group comprising 286 individuals (89 MGUS and 179 MM patients), statistically significant differences (Mann-Whitney test) between MGUS and MM at the time of diagnosis were found in the serum levels of HGF (hepatocyte growth factor), VEGF (vascular endothelial growth factor), ICTP (intercellular - carboxy-terminal telopeptide of type I collagen), PINP (procollagen type I N-terminal propeptide), OPG (osteoprotegerin) and syndecan-1/CD138, but not in Fas. Multivariate analysis (logistic regression) revealed an unsatisfactory potential of all the 7 studied indicators to discriminate between MGUS and MM. A deeper analysis showed statistically significant differences between MGUS and the initial/asymptomatic phase of MM (stage 1 according to the International Staging System) only in the cases of syndecan-1 (p=0.001) and Fas (p=0.008). The assessment of initial values of HGF, VEGF, ICTP, PINP, OPG, syndecan-1 and Fas showed a statistically significant relation (log rank test) to the overall survival (OS) in a group of 132 patients treated with conventional chemotherapy only in the cases of syndecan-1 (p=0.0002) and Fas (p=0.018), but in none of the investigated parameters in a group of 74 patients treated with HDT/ASCT (high-dose therapy/autologous stem cell transplantation). The analysis showed that, despite significant differences in serum levels of 6 of the 7 studied parameters found between MGUS and MM, none of the markers may be included in the spectrum of indicators used to distinguish the two conditions. Despite the positive relation, especially of syndecan-1 and, to a lesser extent, of Fas to the OS in patients treated with conventional chemotherapy, these prognostic factors are not applicable to HDT/ASCT.