How would you approach therapy for a patient with smoldering multiple myeloma whose light chain ratio has increased to greater than 100 over several years in the absence of any other myeloma-defining events?

I struggle with this as well, but the serum free light chain ratio (SFLC-R) at 100 is not magical for a patient that you've been following. An SFLC-R>100 is predictive of an increased risk to develop CRAB criteria of 60-90% w/in 2 years. This prediction is refined by measuring 24hr UPEP using a bar ...

Context for those answering the questions - the 2014 IMWG diagnostic criteria clearly list a K/L or an L/K ratio over 100 as a myeloma-defining event due to the high risk of progression to a CRAB event within 1-3 years without therapy. But, most of the data underpinning this criterion comes from a s...