Balanced chromosome abnormalities inv(16) and t(15;17) in therapy-related @entity2590 and XXXX : report from an international workshop.

@entity1 @entity0 @entity706 @entity5 @entity6158 @entity2590 @entity3052
The Workshop identified 48 unselected @entity1 with therapy-related @entity2590 or @entity3052 (t-MDS/t-AML) and inv(16), and 41 @entity1 with t(15;17) after chemotherapy (CT) and/or radiotherapy (RT) for a malignant or nonmalignant disease. The primary diseases were: @entity0 , 33 @entity1 ; @entity706 , 24 @entity1 ; various other solid @entity5 , 30 @entity1 ; and nonmalignant diseases, 2 @entity1 . The general type of previous therapy was RT only in 10 @entity1 with an inv(16) and in 12 @entity1 with a t(15;17), alkylating agents plus topoisomerase II inhibitors in 24 @entity1 with an inv(16) and in 18 @entity1 with a t(15;17), topoisomerase II inhibitors only in 5 @entity1 with an inv(16) and in 2 @entity1 with a t(15;17), alkylating agents only in 6 @entity1 in each subgroup, and other types of chemotherapy in 3 @entity1 in each subgroup. Most CT-treated @entity1 (69%) also received RT. The latency period to development of t-MDS/t-AML was short: a median of 22 months in @entity1 with inv(16) and 29 months in @entity1 with t(15;17). Twenty-six @entity1 (54%) with an inv(16) and 17 @entity1 (41%) with a t(15;17) had additional cytogenetic abnormalities, which were unrelated to age and survival in both subgroups. Trisomy of chromosomes 8, 21, and 22 and @entity6158 ) were the most frequent additional abnormalities in the inv(16) subgroup, whereas +8, -5, and del(16q) were most frequent in the t(15;17) subgroup. The disease was overt t-AML in 38/48 @entity1 (79%) with an inv(16) and in 38/41 @entity1 (93%) with a t(15;17). Thirty-three of 39 intensively treated @entity1 (85%) with an inv(16) obtained a complete remission, whereas 24 of 35 intensively treated @entity1 (69%) with a t(15;17) obtained a complete remission. The median overall survival of intensively treated @entity1 was 29 months in both cytogenetic subgroups. In the inv(16) subgroup, @entity1 younger than 55 years of age had a longer survival when compared with older @entity1 (P = 0.006). The study supports the observation that t-MDS/t-AML with inv(16) and t(15;17) is often associated with prior therapy with topoisomerase II inhibitors; however, a notable finding was the high frequency of treatment with only radiotherapy, 29% of t(15;17) and 21% of inv(16). Response rates to intensive chemotherapy in this study were comparable to those of de novo disease.
