Ann Hematol (1996) 72 : 216–222 Q Springer-Verlag 1996 ORIGINAL ARTICLE F. Thalhammer 7 K. Geissler 7 U. Jäger 7 P. A. Kyrle I. Pabinger 7 M. Mitterbauer 7 H. Gisslinger P. Knöbl 7 K. Laczika 7 B. Schneider 7 O. A. Haas K. Lechner Duration of second complete remission in patients with acute myeloid leukemia treated with chemotherapy: a retrospective single-center study Received: 28 December 1995 / Accepted: 4 January 1996 F. Thalhammer (Y) 7 K. Geissler 7 U. Jäger 7 P. A. Kyrle I. Pabinger 7 M. Mitterbauer 7 H. Gisslinger 7 P. Knöbl K. Laczika 7 K. Lechner Department of Medicine I, Division of Hematology and Blood Coagulation, University of Vienna, Währinger Gürtel 18–20, A-1090 Vienna, Austria B. Schneider Institute of Statistics, University of Vienna, Austria O. A. Haas St. Anna Children’s Hospital, Vienna, Austria Abstract A total of 168 patients with de novo AML were retreated with chemotherapy at relapse following first CR; 66 patients (39%) achieved a second complete remission (CR). The probability of achieving a second CR was highly dependent on the duration of the first remission. Patients who received no or conventional postremission chemotherapy after second CR had a median remission duration of 7.5 months, and the prob- ability of remaining in remission at 3 years was 24%. Patients with a first CR of more than 12 months had a median second remission duration of 18 months. The probability of a second CCR was 35% at 3 years and 24% at 5 years, whereas none of the patients with a first CR of less than 12 months was in remission at 3 years. Only a poor correlation (pp0.31) was found when the durations of the first and second CR were compared in patients with a second relapse. Patients with long-last- ing remissions and long-term survivors after second CR are characterized by a first CR duration of `12 months and favorable or normal cytogenetics. The type of sal- vage treatment seems to be less important for achiev- ment of long-term remission, but it is probably impor- tant to administer consolidation chemotherapy after second CR. Other so-far ill-defined factors may be re- sponsible for the supression of the leukemic clone in patients with long-lasting remissions following chemo- therapy for relapse after second CR. Key words Acute myeloid leukemia 7 Salvage chemotherapy 7 Long-term remission Introduction Relapse of acute myeloid leukemia is a serious event which drastically reduces the probability of cure. Due to the lack of randomized trials, uncertainty exists about the optimal reinduction therapy and the most ef- fective postremission treatment for responding pa- tients. High-dose chemoradiotherapy followed by allo- geneic bone marrow transplantation from an HLA- compatible sibling or unrelated donor is likely the most effective therapy in early relapse or second CR [7], but this option is available for only a few patients. Favora- ble results have also been reported for autologous bone marrow transplantation (ABMT) in second CR [4, 8, 16, 17, 20, 21]. These series, however, included highly selected groups of patients and were not analyzed on an intent-to-treat basis. Only a few studies have evalu- ated the long-term efficacy of conventional salvage che- motherapy [2, 5, 14, 15, 19, 23]. The aims of this study were (a) to evaluate the long- term efficacy of salvage chemotherapy in patients who have achieved a second CR (excluding patients who un- derwent bone marrow transplantation), and (b) to ana- lyze the factors which determine the duration of second CR and survival in a closely followed and well-charac- terized cohort of patients with AML at a single cen- ter. Material and methods Patients and treatment regimens A total of 370 patients (median age 53 years, range 15–88) with de novo AML were treated between 1978 and 1995 at our institu- tion. Induction chemotherapy consisted of one or two courses of the 3c7 regimen [daunorubicin 45 mg/m 2 or adriamycin 30 mg/ m 2 days 1–3 and continuous infusion of cytosine arabinoside (ARA-C) 100–200 mg/m 2 daily days 1–7, np306], the DAV pro- tocol [9] (np39), ATRA (np12), or various other protocols (np14). Of these patients, 245 (66%) achieved a complete remis- sion. Postremission treatment consisted of regimens similar to the