No abstract

Key Points• Germ-line CEBPA mutations are highly penetrant, causing early-onset de novo AML associated with favorable survival outcomes.• Familial CEBPA-mutated AML displays a unique model of disease progression, with recurrence caused by novel, independent leukemic episodes.In-depth molecular investigation of familial leukemia has been limited by the rarity of recognized cases. This study examines the genetic events initiating leukemia and details the clinical progression of disease across multiple families harboring germ-line CEBPA mutations. Clinical data were collected from 10 CEBPA-mutated families, representing 24 members with acute myeloid leukemia (AML). Whole-exome (WES) and deep sequencing were performed to genetically profile tumors and define patterns of clonal evolution. Germline CEBPA mutations clustered within the N-terminal and were highly penetrant, with AML presenting at a median age of 24.5 years (range, 1.75-46 years). In all diagnostic tumors tested (n 5 18), double CEBPA mutations (CEBPAdm) were detected, with acquired (somatic) mutations preferentially targeting the C-terminal. Somatic CEBPA mutations were unstable throughout the disease course, with different mutations identified at recurrence. Deep sequencing of diagnostic and relapse paired samples confirmed that relapse-associated CEBPA mutations were absent at diagnosis, suggesting recurrence was triggered by novel, independent clones. Integrated WES and deep sequencing subsequently revealed an entirely new complement of mutations at relapse, verifying the presentation of a de novo leukemic episode. The cumulative incidence of relapse in familial AML was 56% at 10 years (n 5 11), and 3 patients experienced ‡3 disease episodes over a period of 17 to 20 years. Durable responses to secondary therapies were observed, with prolonged median survival after relapse (8 years) and long-term overall survival (10-year overall survival, 67%). Our data reveal that familial CEBPA-mutated AML exhibits a unique model of disease progression, associated with favorable long-term outcomes. (Blood. 2015;126(10)

Summary. High-dose chemotherapy (melphalan) with autologous marrow stem cell support (AMSCS) results in high response rates in multiple myeloma (MM), with up to 50% of patients achieving complete remission. However, these remissions are generally not durable. As the cytokine interferon alpha has been shown to prolong partial response following conventional chemotherapy, this trial was conducted to evaluate its role following high-dose chemotherapy. 85 patients were randomly assigned to maintenance treatment with interferon alpha, 3 × 10 6 units/m 2 subcutaneously three times weekly until relapse or no further treatment following recovery from high-dose chemotherapy (melphalan 140-200 mg/m 2 or busulphan 16 mg/kg) combined with AMSCS. At 5·8 years following the accrual of the last patient in this trial, 38 patients had died, 17 in the interferon arm and 21 in the control arm. The median progression-free survival (PFS) in the 42 patients randomized to interferon alpha was 46 months versus 27 months in the controls. Both overall survival and PFS, which were highly significant at median follow-up of 52 months, have now ceased to be significant, because most patients have ultimately succumbed to their disease. Interferon was tolerated by the majority of patients with very good compliance. Toxicity consisted mainly of flu-like symptoms and malaise which were usually self-limiting. The results of such a pilot study should be carefully interpreted and the benefits of interferon should be confirmed in larger multicentre studies in the setting of minimal residual disease following autologous transplantation.