Unusual discordant responses in two multiple myeloma patients during bortezomib treatment.
BACKGROUND
Cases of discordant responses in multiple myeloma (MM) patients after thalidomide therapy have been sometimes reported, in which extramedullary masses progress or present de novo with a simultaneous serum monoclonal protein reduction.


METHODS
We hereby report, for the first time, on two cases of MM patients with extramedullary myeloma localizations that developed during Velcade (bortezomib, PS341) treatment with a concomitant serum monoclonal protein reduction.


RESULTS
We observed in both patients a very good response in the serum monoclonal protein level, while extramedullary lesions appeared in the central nervous system and subcutaneously.


CONCLUSIONS
We discuss pharmacokinetics of bortezomib and physiopathology of this unusual event and review the literature.
Pirrotta
Maria Teresa
MT
Division of Hematology and Transplants, University of Siena, Policlinico Santa aria alle Scotte, Siena, Italy.
Gozzetti
Alessandro
A
Cerase
Alfonso
A
Bucalossi
Alessandro
A
Bocchia
Monica
M
Defina
Marzia
M
Lauria
Francesco
F
D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001897:Boronic Acids / Q000627:therapeutic use*; D000069286:Bortezomib; D002531:Cerebellum / Q000473:pathology; D003907:Dexamethasone / Q000627:therapeutic use; D018450:Disease Progression; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D019008:Drug Resistance, Neoplasm; D017809:Fatal Outcome; D005260:Female; D006801:Humans; D007145:Immunoglobulin kappa-Chains / Q000097:blood; D007146:Immunoglobulin lambda-Chains / Q000096:biosynthesis; D008297:Male; D008578:Meninges / Q000473:pathology; D009101:Multiple Myeloma / Q000188:drug therapy* / Q000473:pathology; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D010950:Plasma Cells / Q000473:pathology; D011719:Pyrazines / Q000627:therapeutic use*; D012867:Skin / Q000473:pathology
D000970:Antineoplastic Agents; D001897:Boronic Acids; D007145:Immunoglobulin kappa-Chains; D007146:Immunoglobulin lambda-Chains; D011719:Pyrazines; D000069286:Bortezomib; D003907:Dexamethasone