An analysis of which subgroups of multiple myeloma patients, divided according to b(2)-microglobulin and plasma cell labeling index, benefit from high dose vs conventional chemotherapy.
OBJECTIVE
The clinical advantage of high-dose therapy (HDT) over standard treatment for multiple myeloma (MM) patients has been recently assessed. Which patient subgroups benefit most from this approach is unclear.


METHODS
To address this issue, the outcome of 54 patients under 55 years old treated with HDT was compared with that of 101 age-matched controls selected from 390 patients who received standard melphalan and prednisone (MP) chemotherapy in a national multi-center trial (M90 protocol).


RESULTS
The complete response (CR) rate was 50% in the HDT group compared to 5% in the MP group. Event-free survival (EFS) was three times longer for the HDT patients (median 34.5 vs 12.2 months, p<0. 0001), though the controls enjoyed a prolonged survival after relapse, and hence there was no statistically significant difference in OS. Overall survival (OS) was analyzed in relation to to two major prognostic factors: b(2)-microglobulin (b(2)-M) and bone marrow plasma cell labeling index (LI). HDT significantly improved OS in poor prognosis patients with a high LI (>1.2%), (median 49.5 vs 32.5 months, p<0.03), whereas it did not prolong OS in poor prognosis patients with high b(2 )-M (> 3 mg/L).


CONCLUSIONS
In conclusion, HDT has a major impact on CR and EFS, and is the treatment of choice for patients with a high LI. Alternative strategies should be adopted in poor prognosis patients with high b(2 )-M.
Boccadoro
M
M
Divisione Universitaria di Ematologia, Azienda Ospedaliera S. Giovanni Battista di Torino, via Genova 3, 10126 Turin, Italy. mario.boccadoro@unito
Tarella
C
C
Palumbo
A
A
Argentino
C
C
Triolo
S
S
Dominietto
A
A
Callea
V
V
Lauta
V M
VM
Molica
S
S
Musto
P
P
Marmont
F
F
Gianni
A M
AM
Pileri
A
A
D000970:Antineoplastic Agents / Q000008:administration & dosage*; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D002452:Cell Count; D018572:Disease-Free Survival; D004305:Dose-Response Relationship, Drug; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008875:Middle Aged; D009101:Multiple Myeloma / Q000628:therapy*; D010950:Plasma Cells / Q000473:pathology*; D012720:Severity of Illness Index; D015996:Survival Rate; D016896:Treatment Outcome; D001613:beta 2-Microglobulin / Q000097:blood*
D000970:Antineoplastic Agents; D001613:beta 2-Microglobulin