Clinicobiological features and outcome of acute promyelocytic leukemia occurring as a second tumor: The GIMEMA experience

We analyzed the clinicobiological features and treatment outcome of a series of acute promyelocytic leukemias (APLs) occurring as a second tumor (APL-st's, n = 51) and compared these with a large group of de novo APL cases (n = 641), both observed by the Italian cooperative group GIMEMA. In the APL-st group, 37 patients had received radiotherapy and/or chemotherapy for their primary malignancy (PM), while 14 had been treated by surgery alone. Compared with de novo APL patients, APL-st patients were characterized by a predominance of females (P <.003), higher median age (P <.05), and worse performance status (P <.005). The median time elapsed between PM and APL-st was 36 months, with a longer latency for patients treated with surgery alone. No significant differences were found with regard to karyotypic lesions or type of promyelocytic leukemia/retinoic acid receptor alpha (PML/RARalpha) fusion in the 2 cohorts. A high prevalence of PMs of the reproductive system was observed among the female APL-st population (24 [71%] of 34 patients in this group had suffered from breast, uterine, or ovarian cancer). Thirty-one APL-st and 641 de novo APL patients received homogeneous APL therapy according to the all-trans retinoic acid (ATRA) and idarubicin regimen (the AIDA regimen). The complete remission (CR), 4-year event-free survival (EFS), and 4-year overall survival (OS) rates were 97% and 93%, 65% and 68%, and 85% and 78% in the APL-st and de novo APL groups, respectively. In spite of important clinical differences (older age and poorer performance status), the APL-st group responded as well as the de novo APL group to upfront ATRA plus chemotherapy, probably reflecting genetic similarity.