A. Guerci

We designed a multicenter randomized trial comparing chemotherapy with daunorubicin-Ara C (chemotherapy group) and all transretinoic acid (ATRA) combined to the same chemotherapy (ATRA group) in newly diagnosed APL patients aged 65 years or less. The major endpoint of the study was event-free survival (EFS) ("events" being defined as failure to achieve complete remission [CR], occurrence of relapse, or death in CR). Early termination of the trial was decided after the first interim analysis, as EFS was significantly higher in the ATRA group. At the time, 101 patients had been randomized (54 in the ATRA group and 47 in the chemotherapy group). In the ATRA group, 49 (91%) patients achieved CR, 5 (9%) had early death, and 0 had resistant leukemia, compared with 38 (81%), 4 (8%), and 5 (10%) patients, respectively, in the chemotherapy group. The difference in CR rate between the two groups was not significant. The duration of coagulopathy was significantly reduced in the ATRA group, compared with the chemotherapy group. In the ATRA group, six patients relapsed after 7 to 15.5 months. In the chemotherapy group, 12 patients relapsed after 1 to 16 months, and 2 died in CR. Kaplan-Meier EFS was estimated at 79% +/- 7% and 50% +/- 9% at 12 months, respectively, in the ATRA and the chemotherapy group (P = .001). Kaplan-Meier estimate of relapse was 19% +/- 8% and 40% +/- 12% at 12 months (P = .005). In conclusion, ATRA followed by chemotherapy increases EFS in newly diagnosed APL. These results strongly suggest that ATRA should be incorporated in the front line therapy of newly diagnosed APL.

All trans-retinoic acid (ATRA) syndrome is a life-threatening complication of uncertain pathogenesis that can occur during the treatment of acute promyelocytic leukemia (APL) by ATRA. Since its initial description, however, no large series of ATRA syndrome has been reported in detail. We analyzed cases of ATRA syndrome observed in an ongoing European trial of treatment of newly diagnosed APL. In this trial, patients 65 years of age or less with an initial white blood cell count (WBC) less than 5,000/microL were initially randomized between ATRA followed by chemotherapy (CT) (ATRA-->CT group) or ATRA with CT started on day 3; patients with WBC greater than 5,000/microL received ATRA and CT from day 1; patients aged 66 to 75 received ATRA-->CT. In patients with initial WBC less than 5, 000/microL and allocated to ATRA-->CT, CT was rapidly added if WBC was greater than 6,000, 10,000, 15,000/microL by days 5, 10, and 15 of ATRA treatment. A total of 64 (15%) of the 413 patients included in this trial experienced ATRA syndrome during induction treatment. Clinical signs developed after a median of 7 days (range, 0 to 35 days). In two of them, they were in fact present before the onset of ATRA. In 11 patients, they occurred upon recovery from the phase of aplasia due to the addition of CT. Respiratory distress (89% of the patients), fever (81%), pulmonary infiltrates (81%), weight gain (50%), pleural effusion (47%), renal failure (39%), pericardial effusion (19%), cardiac failure (17%), and hypotension (12%) were the main clinical signs, and 63 of the 64 patients had at least three of them. Thirteen patients required mechanical ventilation and two dialysis. A total of 60 patients received CT in addition to ATRA as per protocol or based on increasing WBC; 58 also received high dose dexamethasone (DXM); ATRA was stopped when clinical signs developed in 30 patients. A total of 55 patients (86%) who experienced ATRA syndrome achieved complete remission (CR), as compared with 94% of patients who had no ATRA syndrome (P = .07) and nine (14%) died of ATRA syndrome (5 cases), sepsis (2 cases), leukemic resistance (1 patient), and central nervous system (CNS) bleeding (1 patient). None of the patients who achieved CR and received ATRA for maintenance had ATRA syndrome recurrence. No significant predictive factors of ATRA syndrome, including pretreatment WBC, could be found. Kaplan Meier estimates of relapse, event-free survival (EFS), and survival at 2 years were 32% +/- 10%, 63% +/- 8%, and 68% +/- 7% in patients who had ATRA syndrome as compared with 15% +/- 3%, 77% +/- 2%, and 80% +/- 2% in patients who had no ATRA syndrome (P = .05, P = .003, and P = .03), respectively. In a stepwise Cox model that also included pretreatment prognostic variables, ATRA syndrome remained predictive for EFS and survival. In conclusion, in this multicenter trial where CT was rapidly added to ATRA in case of high or increasing WBC counts and DXM generally also used at the earliest clinical sign, the incidence of ATRA syndrome was 15%, but ATRA syndrome was responsible for death in only 1.2% of the total number of patients treated. However, occurrence of ATRA syndrome was associated with lower EFS and survival.

We entered 26 patients with newly diagnosed acute promyelocytic leukemia (APL) in a pilot study of all-transretinoic acid (ATRA) followed by intensive chemotherapy. Median age was 46 (range 25 to 63). No patient presented with leukocytes > 10 x 10(9)/L or had the microgranular APL variant. Cytogenetic analysis (25 patients) found a t(15;17) in 24 cases. Patients were scheduled to receive ATRA (45 mg/m2/d) until complete remission, followed by an intensive daunorubicin (DNR) + Ara C course ("4 + 7" course), then three "2 + 5" DNR + Ara C courses and maintenance chemotheapy. However, the "4 + 7" course was administered in emergency if hyperleukocytosis rapidly developed to prevent leukostasis. Twenty-five patients (96%) achieved CR, 14 with ATRA alone and 11 after the addition of the "4 + 7" course on day 2 to 30 of treatment, because leukocytes rapidly increased (9 cases), because of resistance to ATRA (1 case), and development of organomegaly (1 case). The remaining patient died on day 6, from CNS bleeding. Apart from hyperleukocytosis, side effects were usually moderate. In the 11 patients who could be studied in vitro, a very good correlation was found between in vivo and vitro differentiation and proliferation of APL blasts with ATRA. Three patients were allografted after the "4 + 7" course. Four patients did not receive this course but received the subsequent "2 + 5" courses and maintenance. The remaining patients followed the scheduled protocol. Three patients relapsed after 8, 11, and 15 months (including one allografted patient). Two patients died in CR, after 6 and 17 months. The other 20 patients remained in CR after 18+ to 34+ months (median 21). Actuarial disease free interval (DFI) and event free survival (EFS) were 87% and 77%, respectively, after 18 months. These results were compared to those obtained in our previous APL 84 trial with chemotherapy alone in newly diagnosed APL (after excluding patients included in this trial who presented with hyperleukocytosis). In APL 84 trial, the CR rate was 76%, the actuarial DFI and EFS were 59% and 48% after 18 months, respectively. Differences with the pilot study of ATRA followed by chemotherapy were significant for DFI (P = .02), EFS (P = .006), but not for CR rate (P = .08). Although this is a historical comparison, these results suggest that ATRA followed by chemotherapy may prove superior to chemotherapy alone in newly diagnosed APL, by slightly increasing the CR rate, but perhaps more importantly by reducing the relapse rate.(ABSTRACT TRUNCATED AT 400 WORDS)

PURPOSE: To analyze patient cases of therapy-related acute promyelocytic leukemia (tAPL), occurring after chemotherapy (CT), radiotherapy (RT) or both for a prior disorder, diagnosed during the last 20 years in three European countries. PATIENTS AND METHODS: The primary disorder and its treatment, interval from primary disorder to tAPL, characteristics of tAPL, and its outcome were analyzed in 106 patients. RESULTS: Eighty of the 106 cases of tAPL were diagnosed during the last 10 years, indicating an increasing incidence of tAPL. Primary disorders were predominantly breast carcinoma (60 patients), non-Hodgkin's lymphoma (15 patients), and other solid tumors (25 patients). Thirty patients had received CT alone, 27 patients had received RT alone, and 49 patients had received both. CT included at least one alkylating agent in 68 patients and at least one topoisomerase II inhibitor in 61 patients, including anthracyclines (30 patients), mitoxantrone (28 patients), and epipodophyllotoxins (19 patients). Median interval from primary disorder to tAPL diagnosis was 25 months (range, 4 to 276 months). Characteristics of tAPL were generally similar to those of de novo APL. With treatment using anthracycline-cytarabine-based CT or all-trans-retinoic acid combined with CT, actuarial survival was 59% at 8 years. CONCLUSION: tAPL is not exceptional, and develops usually less than 3 years after a primary neoplasm (especially breast carcinoma) treated in particular with topoisomerase II-targeted drugs (anthracyclines or mitoxantrone and less often etoposide). Characteristics and outcome of tAPL seem similar to those of de novo APL.