Prolonged administration of all-trans retinoic acid in combination with intensive chemotherapy and G-CSF for adult acute myelogenous leukemia: single-centre pilot study in different risk groups.
BACKGROUND
An exploratory trial was conducted to evaluate toxicity and potential therapeutic role of all trans-retinoic acid (ATRA) given long-term together with chemotherapy and G-CSF to adult patients with acute myelogenous leukemia (AML).


METHODS
ATRA was administered orally at 45 mg/m(2)/day on days 1-14 and 25 mg/m(2)/day on days 15-28 of two standard cycles (idarubicin, etoposide, cytarabine, G-CSF) and of up to three high-dose courses (cytarabine, G-CSF). The results obtained in 19 patients enrolled in the ATRA trial were compared with those from 29 comparable cases treated with the same schedule without ATRA, according to patient risk class and an in vitro study.


RESULTS
ATRA was administered for a median of 52 days to the patients selected for study who achieved a remission. ATRA-related toxicity was mostly non-severe apart from high incidence of headache in conjunction with high-dose cytarabine. Complete remission (CR) rate after cycle 1 (54%), kinetics of hematological recovery, postremission treatment realization, disease-free survival (DFS 37.5% at three years) and overall survival (30% at three years) were not different between ATRA-treated and untreated patients. The only significant prognostic factor was the patient risk class, as defined by cytogenetics and other clinical criteria: DFS rate was 57% at three years in standard-risk cases compared to only 19% in the high-risk group, with no influx by ATRA in either category. The in vitro study, in patients with a definite clinical response, failed to document any inhibitory or pro-apoptotic effect of ATRA on AML blast cells.


CONCLUSIONS
As a consequence to these results, the pilot ATRA phase was closed. This study does not suggest a significant role for the present ATRA schedule as an adjunct to standard antileukemic therapy in adult AML.
Division of Haematology, Cytogenetics Unit, Ospedali Riuniti, Bergamo, Italy. basbas@virgilio.it
Renato
R
Bassan
Barbara
B
Chiodini
Teresa
T
Lerede
Ursula
U
Giussani
Elena
E
Oldani
Maurizio
M
Buelli
Andrea
A
Rossi
Piera
P
Viero
Alessandro
A
Rambaldi
Tiziano
T
Barbui
D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D017209:Apoptosis / Q000187:drug effects; D003561:Cytarabine / Q000008:administration & dosage / Q000009:adverse effects; D018572:Disease-Free Survival; D005047:Etoposide / Q000008:administration & dosage / Q000009:adverse effects; D005260:Female; D000069585:Filgrastim; D016179:Granulocyte Colony-Stimulating Factor / Q000008:administration & dosage / Q000627:therapeutic use*; D006261:Headache / Q000139:chemically induced; D006801:Humans; D015255:Idarubicin / Q000008:administration & dosage / Q000009:adverse effects; D007951:Leukemia, Myeloid / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology; D015993:Life Tables; D008297:Male; D008875:Middle Aged; D014411:Neoplastic Stem Cells / Q000187:drug effects; D010349:Patient Compliance; D010865:Pilot Projects; D011994:Recombinant Proteins; D012074:Remission Induction; D016019:Survival Analysis; D017211:Treatment Failure; D014212:Tretinoin / Q000008:administration & dosage / Q000009:adverse effects
D011994:Recombinant Proteins; D003561:Cytarabine; D016179:Granulocyte Colony-Stimulating Factor; D014212:Tretinoin; D005047:Etoposide; D000069585:Filgrastim; D015255:Idarubicin