Low tumor mass assumed if
all
4 of the following are present:
(1) hemoglobin > 10.5 g/dL
(2) corrected serum calcium level <= 11.5 mg/dL, using the correction for serum albumin (Payne, 1973)
(3) low serum myeloma protein (IgG < 5 g/dL; IgA < 3 g/dL)
(4) must not have extensive bone lesions
Intermediate tumor mass
(1) not low tumor mass AND not high tumor mass
High tumor mass assumed if
any
1 of the following are present:
(1) hemoglobin < 8.5 g/dL
(2) corrected serum calcium > 11.5 g/dL
(3) increased serum myeloma protein (IgG > 7 g/dL; IgA > 5 g/dL)
where:
• Conversion of calcium from mg/dL to mmol/L is 0.25; from mmol/L to mg/dL is 4.0.
• For patients with only Bence-Jones proteinuria, then decision based classification on hemoglobin, corrected calcium level and extent of bony lesions.
corrected total serum calcium if normal albumin =
= (current total serum calcium) + (4 - (current albumin in g/dL)) mg/dL
Interpretation:
• A low tumor mass associated with good prognosis and long remission periods.
• A high tumor mass associated with poor prognosis, often due to short remission after treatment.
