Flow cytometric disease monitoring in multiple XXXX : the relationship between normal and neoplastic plasma cells predicts outcome after transplantation.

@entity1582 @entity1
Conventional monitoring strategies for @entity1582 are not sufficiently sensitive to identify @entity1 likely to benefit from further therapy immediately after transplantation. We have used a sensitive flow cytometry assay that quantitates normal and neoplastic plasma cells to monitor the bone marrow of 45 @entity1 undergoing high-dose chemotherapy. Neoplastic plasma cells were detectable at 3 months after transplantation in 42% of @entity1 . Once detected, neoplastic cell levels increased steadily until clinical progression: these @entity1 had a significantly shorter progression-free survival (PFS) (median, 20 months) than those with no detectable disease (median, longer than 35 months; P =.003). Neoplastic plasma cells were detectable in 27% (9 of 33) of immunofixation-negative complete-remission @entity1 . These @entity1 had a significantly shorter PFS than immunofixation-negative @entity1 with no detectable neoplastic plasma cells (P =.04). Normal plasma cells were present in 89% of @entity1 immediately after transplantation, but were not sustained in most cases. @entity1 with only normal phenotype plasma cells present at 3 months after transplantation and also at second assessment had a low risk of disease progression. @entity1 with neoplastic plasma cells present at 3 months after transplantation, or with only normal plasma cells present at first assessment and only neoplastic plasma cells at second assessment, had a significantly higher risk of early disease progression (P <.0001) with a 5-year survival of 54% for the high-risk group, compared with 100% in the low-risk group (P =.036). Analysis of normal and neoplastic plasma cell levels is more sensitive than immunofixation and can identify which @entity1 may benefit from additional treatment strategies at an early stage after transplantation.
