Outcome of elderly patients with acute promyelocytic leukemia: results of the German Acute Myeloid Leukemia Cooperative Group.

Despite improvement of prognosis, older age remains a negative prognostic factor in acute promyelocytic leukemia (APL). Reports on disease characteristics and outcome of older patients are conflicting. We therefore analyzed 91 newly diagnosed APL patients aged 60 years or older (30 % of 305 adults with APL) registered by the German AML Cooperative Group (AMLCG) since 1994; 68 patients (75 %) were treated in studies, 23 (25 %) were non-eligible, and 31 % had high-risk APL. Fifty-six patients received induction therapy with all-trans retinoic acid and TAD (6-thioguanine, cytarabine, daunorubicin), and consolidation and maintenance therapy. Treatment intensification with a second induction cycle (high dose cytarabine, mitoxantrone; HAM) was optional (n = 14). Twelve patients were randomized to another therapy not considered in this report. The early death rate was 48 % in non-eligible and 19 % in study patients. With the AMLCG regimen, 7-year overall, event-free and relapse-free survival (RFS) and cumulative incidence of relapse were 45 %, 40 %, 48 %, and 24 %, respectively. In patients treated with TAD-HAM induction, 7-year RFS was superior (83 %; p = 0.006) compared to TAD only, and no relapse was observed. In our registered elderly patients, we see a high rate of non-eligibility for treatment in studies and of high-risk APL. In patients who can undergo a curative approach, intensified chemotherapy is highly effective, but is restricted to a selection of patients. Therefore, new less toxic treatment approaches with broader applicability are needed. Elderly patients might be a particular target group for concepts with arsenic trioxide.