Prophylactic intrathecal chemotherapy in acute promyelocytic leukemia (APL)

Central nervous system relapse in a patient with acute promyelocytic leukaemia: does the risk stratification matter?

Extramedullary relapse is an uncommon complication of acute promyelocytic leukaemia (APL). The most common site of extramedullary relapse is the central nervous system (CNS), and the majority of CNS relapses occur in patients with high-risk disease in which white blood cell count at presentation is greater than 10×10(3)/μL. The best management of such patients is still controversial. We describe a 47-year-old man with APL who developed two CNS relapses which were diagnosed through the presence of t(15;17)(q22;q21) on PCR of the cerebrospinal fluid (CSF), despite presenting initially with intermediate-risk disease. We conclude that the intermediate risk group is very heterogeneous and these patients sometimes may behave like high-risk patients. Also, clinicians should take into account symptoms that can be related to CNS relapse in patients with APL and consider lumbar puncture even if radiological imaging does not reveal anything.

Incidence of extramedullary disease in patients with acute promyelocytic leukemia: a single-institution experience

Using current treatment regimens, over 90% of patients with acute promyelocytic leukemia will achieve complete remission (CR). However, approximately 30% of these patients will relapse, including a small proportion who will develop extramedullary disease (EMD). In this study, we investigated the incidence of EMD in 263 patients with APL who were treated at our institution from January 1990 to May 2008. With a median follow-up of 31 months (range 2 days-203 months), 8 (3%) patients developed EMD. The most commonly affected site was the central nervous system (n = 7). Before developing EMD, one patient had achieved CR with a chemotherapy-only regimen, six patients had achieved CR with all-trans-retinoic acid (ATRA)-based regimens, and one patient had achieved CR with an ATRA plus arsenic trioxide (ATO)-based regimen. The EMD conferred a poor prognosis; five patients died within 4 months of developing EMD. The molecular status did not predict EMD; four patients had a negative PCR for the PML-RARA transcripts prior to relapse with EMD. In conclusion, the incidence of EMD is low. We were unable to identify any specific factors that could predict the development of EMD.

Effective treatment of acute promyelocytic leukemia with all-trans-retinoic acid, arsenic trioxide, and gemtuzumab ozogamicin

PURPOSE

We examined the outcome of patients with newly diagnosed acute promyelocytic leukemia (APL) treated with all-trans-retinoic acid (ATRA) and arsenic trioxide (ATO) with or without gemtuzumab ozogamicin (GO) but without traditional cytotoxic chemotherapy.

PATIENTS AND METHODS

From February 2002 to March 2008, 82 patients with APL were treated with a combination of ATRA plus ATO. The first cohort of 65 patients received ATRA and ATO (beginning on day 10 of ATRA). High-risk patients (WBCs >or= 10 x 10(9)/L) received GO on the first day. From July 2007, the second cohort of 17 patients received ATRA and ATO concomitantly on day 1. They also received GO on day 1, if high risk, and if their WBC increased to more than 30 x 10(9)/L during induction. Monitoring for PML-RARA fusion gene was conducted after induction and throughout consolidation and follow-up.

RESULTS

Overall, 74 patients achieved complete remission (CR) and one achieved CR without full platelet recovery after the induction, for a response rate of 92%. Seven patients died at a median of 4 days (range, 1 to 24 days) after inclusion in the study from disease-related complications. The median follow-up is 99 weeks (range, 2 to 282 weeks). Among the responding patients, three experienced relapse at 39, 52, and 53 weeks. Three patients died after being in CR for 14, 21, and 71 weeks, all from a second malignancy. The estimated 3-year survival rate is 85%.

CONCLUSION

The combination of ATRA and ATO (with or without GO) as initial therapy for APL was effective and safe and can substitute chemotherapy-containing regimens.