Methods for estimation of bone marrow plasma cell involvement in myeloma: predictive value for response and survival in patients undergoing autologous stem cell transplantation.
In myeloma, the bone marrow plasma cell percentage (BMPC%) is usually estimated independently on the aspirate, core biopsy, and plasma cell labeling index (PCLI) samples. This study was done to determine which of the 3 individual estimates correlates best with complete response (CR) and survival. Seventy-five consecutive patients who underwent SCT for relapsed myeloma were studied. The median BMPC% on the marrow aspirate, core biopsy, and PCLI studies were 20, 25, and 20, respectively. There was a significant correlation between the three methods, rho > 0.65, P < 0.001. However, in 8% of patients the BMPC% was different by an absolute value of 50% between methods. No individual method was predictive for CR. However, the highest estimate of the BMPC% among the three methods was a significant predictor of CR (P = 0.02). Survival following SCT was longer among patients with a low BMPC% (< or =60) by the PCLI method compared to those with higher values, median survival 23 versus 7 months, respectively, P = 0.02. PFS was also different, with survival times of 11 and 5 months, respectively, P = 0.003. Similar results were obtained when the highest estimate of the BMPC% was used in survival analysis (P = 0.02 and 0.004, respectively). Statistical significance was lower when the BMPC% on the aspirate or biopsy used in survival analysis. Compared to any individual method of estimating BMPC%, the highest estimate of the BMPC% is the best predictor of CR in myeloma. It is also prognostic for poor survival and PFS following SCT for myeloma. We recommend that all three methods of estimating BMPC% be routinely performed and that the highest value be used for prognostic purposes.
Rajkumar
S V
SV
Division of Hematology, Mayo Clinic, Rochester, Minnesota 55905, USA. rajkumar.vincent@mayo.edu
Fonseca
R
R
Dispenzieri
A
A
Lacy
M Q
MQ
Lust
J A
JA
Witzig
T E
TE
Therneau
T M
TM
Kyle
R A
RA
Greipp
P R
PR
Gertz
M A
MA
D000328:Adult; D000368:Aged; D001854:Bone Marrow Cells / Q000473:pathology*; D002452:Cell Count; D005260:Female; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D008297:Male; D008722:Methods; D008875:Middle Aged; D009101:Multiple Myeloma / Q000175:diagnosis* / Q000473:pathology / Q000628:therapy; D010950:Plasma Cells / Q000473:pathology*; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D016019:Survival Analysis; D014182:Transplantation, Autologous; D016896:Treatment Outcome