A 68-year-old man with multiple myeloma on lenalidomide maintenance develops new bone pain. X-ray shows lytic lesions in T8 vertebra. Serum M protein rises from 0.3 to 1.8 g/dL over 2 months. He was previously treated with bortezomib-lenalidomide-dexamethasone (VRd). Per IMWG 2016 criteria for progression, what is the minimum requirement to define biochemical relapse requiring treatment?

• A Any increase in serum M protein
• B New bone lesion alone
• C Doubling of M protein within 2 months
• D 25% increase from nadir AND absolute increase ≥0.5 g/dL in serum M protein ✓

Explanation

Per IMWG 2016 uniform response criteria, biochemical progressive disease in myeloma requires: serum M protein increase of ≥25% from the lowest response value AND an absolute increase of ≥0.5 g/dL (or urine M protein ≥200 mg/24h increase, or FLC ratio increase of ≥25% with absolute increase ≥10 mg/dL). Both the percentage and absolute criteria must be met to avoid over-diagnosing progression from minor fluctuations. New bone lesions independently fulfill progression criteria regardless of M protein.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.