Increase in the Incidence of Secondary Acute Myeloid Leukemia (2-AML): A Single Institution Experience Over 20 Years.

Secondary acute myeloid leukemia (2-AML) is a distinctive clinical syndrome occurring after primary malignancy treated or not with chemotherapy (CT), radiotherapy (RT), surgery, or a multimodality strategy. We analyzed the data on 2898 consecutive patients (pts) with AML (WHO criteria) referred to our institution between 1985 and 2005, including 1642 males and 1256 females. The median age was 58 years (range, 13–89 years) for pts with de novo AML (1-AML) (n=2198) and 66 years (range, 18–89 years) for those with 2-AML (n=700). 171 pts (18%) were treated for 2-AML between 1985 and 1994 versus 529 patients (27%) treated between 1995 and 2005 (p<0.001). The predominant primary malignancies included lymphoma (18%), breast (16%), and prostate (13%). Pts had been administered various cytotoxic chemotherapy agents (185 pts, 26%) and RT (102 pts, 15%); 182 (26%) had undergone both modalities, and 231 pts (33%) had undergone surgery alone. At diagnosis, 181 (26%) pts with 2-AML had diploid cytogenetics versus 845 (38%) pts with 1-AML (p<0.001). 252 (32%) pts with 2-AML had clonal abnormalities involving chromosomes 5 and 7 versus 383 (17%) pts with 1-AML (p<0.001), and 49 (7%) pts with 2-AML had 11q abnormalities versus 73 (3%) with 1-AML (p<0.001). Pts undergoing CT/RT had a worse cytogenetic risk profile compared to those undergoing surgery alone with more clonal abnormalities involving chromosomes 5 and 7 (36% versus 24%; p=0.002) and chromosome 11 (10% versus 2%; p<0.001), and less diploid karyotype (19% versus 39%; p<0.001). Median survival time after diagnosis of 2-AML was 6 months with 2- and 5-year survival rates of 18% and 11%, respectively. The median survival for pts treated with surgery alone for the primary cancer was 8 months versus 5 months for those receiving CT/RT (p=0.007); their 2- and 5-year survival rates were 22% and 14% and 16% and 9%, respectively. The median survival for pts treated for their primary cancer between 1985 and 1994 was 4 months versus 6 months for those treated after 1994 (p=0.089); their 2-year and 5-year survival rates were 16% and 9% and 19% and 12%, respectively. In conclusion, the incidence of 2-AML is increasing; patients receiving CT/RT had worse cytogenetic profiles and clinical outcomes than those receiving surgical treatment alone. There remains to be seen whether increased use of targeted therapies as prime modality of therapy in primary cancers will be associated with a decreased risk of 2-AML.