Relationship between depth of response and outcome in multiple myeloma.
OBJECTIVE
High-dose therapy with autologous stem-cell transplantation (HDT-ASCT) is now almost standard therapy for many patients with multiple myeloma, partly because of higher complete response (CR) rates. Some studies suggest that tandem transplantation gives superior results. The aim of this study was to determine whether the depth of the response to HDT-ASCT leads to an improvement in time to progression (TTP) and overall survival (OS). We hypothesized that patients with CR before HDT-ASCT (BCR) will have their disease burden reduced further and experience a longer TTP and perhaps OS.


METHODS
All patients who achieved BCR or CR after HDT-ASCT (ACR) were identified. The characteristics and long-term outcome of these patients were evaluated.


RESULTS
We identified 14 patients with BCR and 103 patients with ACR who were treated in similar fashion. The patients have been followed for more than 6 years, and the median for OS has not been reached (60-month survival, 55% for BCR and 63% for ACR; P = .83). The median TTP was 43 months for BCR and 34 months for ACR (P = .39).


CONCLUSIONS
The depth of the response in myeloma does not necessarily lead to an improvement in TTP and OS. Tumor dynamics considerations show that the yield from sequential cycles of chemotherapy decreases. Patients who achieve CR with the first transplant can be safely observed without jeopardizing OS.
Dingli
David
D
Division of Hematology, Mayo Clinic College of Medicine, Rochester, MN 55905, USA.
Pacheco
Jorge M
JM
Nowakowski
Grzegorz S
GS
Kumar
Shaji K
SK
Dispenzieri
Angela
A
Hayman
Suzanne R
SR
Lacy
Martha Q
MQ
Gastineau
Dennis A
DA
Gertz
Morie A
MA
D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000008:administration & dosage*; D005260:Female; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000188:drug therapy*; D047368:Tumor Burden / Q000187:drug effects
D000970:Antineoplastic Agents