Therapy-related myelodysplastic syndrome and acute myeloid leukemia with 17p deletion. A report on 25 cases

Two main types of therapy-related acute myeloid leukemias (tAML) and myelod ysplastic syndromes (tMDS) have been described. The first classical type ty pically occurs late after use of alkylating agents and presents as MDS with -7/del 7q and/or -5/del5q. The second form occurs early after the use of a gents targeted at topoisomerase II, and presents as AML with 11q23 or other rearrangements of de novo AML. Recently, we and others reported, in AML an d MDS, a strong correlation between cytogenetic rearrangements leading to 1 7p deletion, a specific type of dysgranulopoiesis and p53 mutation; several of those cases of 17p- syndrome were therapy-related. Over the last 15 yea rs, we observed 25 cases of tAML and tMDS with 17p deletion, which represen ted 36% of the AML and MDS with 17p deletion diagnosed during that period. Median age was 59 years. Twenty-one patients had tMDS and four tAML. Typica l dysgranulopoiesis and p53 mutation and/or overexpression were seen in 22 of 24 and 16 of 19 evaluable patients, respectively. 17p deletion resulted from unbalanced translocations involving 17p (18 cases), monosomy 17 (five cases), i(17q) (one case) or del 17p (one case). Twenty-one patients also h ad -5/del 5q, and/or -7/del 7q. Median interval from treatment of the first tumor of tAML and tMDS was 94 months (range 19-252). Median survival was o nly 7 months. Based on primary tumor and antineoplastic agents used, patien ts could be relatively well divided into two groups: a first group of 11 ca ses, occurring mainly after a lymphoid neoplasm (eight cases) treated by ch emotherapy with an alkylating agent (10 cases), and a second group of 14 ca ses occurring after essential thrombocythemia (ET) or polycythemia vera (PV ) treated mainly by hydroxyurea (10 cases), pipobroman (eight cases), P-32 (SIX cases) but rarely by alkylating agents (two cases). -7/del 7q was foun d in 10 of the 11 patients in the first group, as compared to three of the 14 patients of the second group (P = 0.0001). Therefore, therapy-related ca ses represent a high proportion of AML and MDS with the 17p- syndrome. They have many features in common with classical tMDS and tAML, including long interval from the first tumor, a usual preleukemic phase, and frequent occu rrence of -5/del 5q. About one half of them, in addition, occur after alkyl ating agents and generally carry -7/del 7q. The other half, however, occur mainly after ET or PV treated by hydroxyurea or other non-alkylating agents , and usually have no -7/del 7q. These findings bring further support to a possible relationship between prior drugs used and cytogenetic rearrangemen ts in tAML and tMDS.