Most of the studies discussed in this chapter have sought to establish whether FLC analysis is prognostic independently of other markers. However, it would also be of value if a simple serum test could replace a more expensive and/or invasive investigation such as multi-parameter flow cytometry or cytogenetic analysis.
Kumar et al.  studied the relationship between sFLC results and the presence of IgH translocations in 314 MM patients at diagnosis. The median κ/λ sFLC ratio and dFLC were higher in patients with IgH translocations, particularly t(14;16), but multivariate analysis indicated that sFLC abnormalities were independent risk factors and better prognosis was obtained using a combination of both the genetic and sFLC risk factors.