The significance of tumour cell immunophenotype in myeloma and its impact on clinical outcome.
OBJECTIVE
Antigen expression of multiple myeloma (MM) cells is heterogeneous. We have investigated the clinical impact of expression of some of the commonly used immunohistochemical markers in the diagnostic work-up of bone marrow trephine biopsy (BMTB) samples in MM.


METHODS
BMTB samples from 107 MM patients who had received an autologous stem cell transplant (ASCT) following chemotherapy were evaluated. In 75 cases, the immunophenotype had been evaluated on two or more occasions on further follow-up.


RESULTS
In the cases evaluated, 32%, 79%, 73%, 39% and 60% of cases had been scored positive for CD20, CD79a, CD56, cyclin D1 and epithelial membrane antigen (EMA) respectively. Absence of CD79a was predictive of poor overall survival (OS) from the time of transplant (p = 0.029) and poor event-free survival (EFS) from the time of transplant (p = 0.003). Absence of EMA (p = 0.02) was predictive of poor EFS from the time of diagnosis. Presence of CD56 was predictive of poor EFS from the time of diagnosis (p = 0.026). On multivariate analysis, only CD79a expression (OS and EFS from the time of transplant) and EMA expression (EFS from the time of diagnosis) maintained their significance. 13 of 75 patients showed an immunophenotypic drift during the disease course. Loss of CD20 (four cases) during the disease course in cases that were previously scored positive correlated with significant worsening both, of OS (p = 0.02) and EFS (p = 0.009) from the time of diagnosis.


CONCLUSIONS
Immunophenotype impacts on clinical outcome in MM.
Ngo
N-T
NT
Department of Histopathology, Hammersmith Hospital and Imperial College, London, UK.
Brodie
C
C
Giles
C
C
Horncastle
D
D
Klammer
M
M
Lampert
I A
IA
Rahemtulla
A
A
Naresh
K N
KN
D000328:Adult; D000368:Aged; D000951:Antigens, Neoplasm / Q000378:metabolism; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D014408:Biomarkers, Tumor / Q000378:metabolism; D001706:Biopsy; D001853:Bone Marrow / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016130:Immunophenotyping; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000175:diagnosis / Q000276:immunology* / Q000628:therapy; D009361:Neoplasm Invasiveness; D033581:Stem Cell Transplantation; D016019:Survival Analysis; D016896:Treatment Outcome
D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor