Risk factors for early mortality, relapse and overall survival in new cases of APL treated by arsenic trioxide

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Background: There are several known risk factors for APL treatment by ATRA and chemotherapy, but risk factors for new cases of APL treated by Arsenic Trioxide are unknown. Methods: Between May 2000 and September 2006, we treated 141 new cases of APL (Median age 28±12.8 y/o min=11, max=71) by 2 hours iv infusion of 0.15mg/kg ATO until complete remission. Trial approved by IRB and consent form obtained. Diagnosis was by clinical and morphologic characteristics and confirmed by cytogenetic and RT-PCR for detection of t(15,17) and presence of PML-RARa. After complete remission patients received consolidation by 28 days infusion of ATO for one or four courses. Known risk factors for APL treatment outcome (including PML-RARa isoforms, presence of MRD during follow up and WBC count at presentation analyzed for early mortality, relapse rate, DFS and OS. Results: Complete remission observed in 121 cases (85.8%) and early mortality rate was 14.9%. short isoform of detected in 36% of patients and 18% presented by WBC more than 10,000/μl. For early mortality, APL differentiation syndrome during treatment and WBC count more than 10,000/μl were risk factors. (P<0.001 and p=0.011 respectively) For DFS only predicting factor for relapse was detection of MRD (by nested PCR or by real time PCR) during follow up (P=0.05). For prediction of OS, again only risk factor was detection of MRD(P<0.0001). Conclusions: Although WBC count before treatment and APL differentiation syndrome during treatment are risk factor for relapse, short isoform of APL is not a risk factor. After achieving to CR only risk factor is detection of MRD.

No significant financial relationships to disclose.

Treatment of acute promyelocytic leukemia with arsenic trioxide without ATRA and/or chemotherapy

INTRODUCTION

Arsenic trioxide is effective and approved for treatment of relapsed or refractory acute promyelocytic leukemia (APL) cases resistant to all-trans retinoic acid (ATRA), but its effect on new cases of APL is not clear.

MATERIALS AND METHODS

We studied 111 patients with APL. Arsenic trioxide was infused at 0.15 mg/kg daily dose, until complete remission was achieved. Then, after 28 days of rest, arsenic trioxide was infused daily for 28 days as consolidation therapy. We studied minimal residual disease (MRD) by semi-sensitive reverse transcription polymerase chain reaction (RT-PCR) on peripheral blood samples.

RESULTS

Complete remission was observed in 95 patients (85.6%). With the median (range) follow-up period of 16.5 (1-57) months, 1- and 2-year disease-free survival was 88.3% and 63.7%, respectively; 24 patients relapsed, 19 of whom achieved a second complete remission, again by arsenic trioxide. Third and fourth remissions were seen in some relapsed patients, again by arsenic trioxide. For patients in complete remission, 1- and 3-year survival was 95.5% and 87.6%, respectively. MRD was positive in four (8.3%) out of 48 cases during 1 year after remission induction; three of them relapsed clinically.

CONCLUSIONS

Arsenic trioxide is effective as first-line treatment for APL. Results of arsenic trioxide combination therapy with chemotherapy/ATRA requires further study.

Bone marrow transplantation in Iran

Seventy-three BMT procedures (42 allogeneic-BMT, 30 autologous-BMT, 1 syngeneic transplant) were undertaken at the Shariati Hospital in Tehran between March 1991 and November 1993. Allogeneic-BMT was performed for thalassaemia major (n = 23), AML in complete remission (n = 3), severe aplastic anaemia (n = 7), CML (n = 7), dyskeratosis congenita (n = 2) and Fanconi anaemia (n = 1). Conditioning regimens comprised busulphan (BU) plus cyclophosphamide (CY) or CY only. Thirty-two (78%) of the 43 patients remain alive 1-34 months after BMT. Twelve patients died: the causes of death were haemorrhagic cystitis (n = 1), CMV pneumonitis (n = 1), GVHD (n = 3), infection (n = 3), rejection (n = 1), VOD (n = 2) and hepatitis (n = 1). Autologous-BMT was performed for patients with AML in CR (n = 16), ALL in CR (n = 9), lymphoma in relapse (n = 3), Ewing sarcoma (n = 1) and multiple myeloma (n = 1). The median age was 18 years. Conditioning regimens were Ara C plus CY, etoposide plus CY and high-dose melphalan. Sixteen (54%) of the 30 patients survive, 14 in continuous complete remission. The causes of death were relapse (AML (n = 7), ALL (n = 4), lymphoma (n = 1)), VOD (n = 1) and infection (n = 1).