Citations

Outcomes of acute myeloid leukemia (AML) in elderly patients unfit for intensive chemotherapy is challenging. Hypomethylating agents (HMAs) can be effective in these patients but responses are usually short‐lived. The majority of patients will either have stable disease or progress through therapy. We hereby describe the outcome of these patients at our institution after they fail HMAs. The data on 56 AML patients at Mayo Clinic, Rochester were reviewed. Patients were considered for our study if they received HMA as frontline therapy for their AML. Out of 56 patients, 15 (27%) patients received azacitidine (AZA) and 41 (73%) received decitabine. Complete remission was found in 10 (18%), with overall response of 28% and median response duration of 10 months. Thirteen (81%) out of 16 responders relapsed. Therefore 53 patients were included in the primary or secondary failure analysis with a median overall survival (OS) of 2 months after the date of failure. Out of 53 patients, 12 (23%) received subsequent treatments. None of the 12 patients who got first salvage therapy achieved remission. Five out of the 12 patients received second salvage therapy, 2 (40%) of which achieved CR. Median OS for patients who received subsequent salvage therapies was better than those who did not receive any subsequent therapy after failing HMA (9.5 vs. 2 months, P = .0009). Outcome for patients who have primary or secondary failure is very poor. Our study provides important historical data for future novel therapies, which are sorely needed for these patients.

Chronic neutrophilic leukemia (CNL) is a potentially aggressive myeloproliferative neoplasm, for which current WHO diagnostic criteria include leukocytosis of ≥25 × 109/L (of which >80% are neutrophils) and with <10 and <1% circulating immature granulocytes and blasts, respectively without dysplasia, clinical, or molecular criteria for other myeloproliferative disorders, nor an identifiable cause for physiologic neutrophilia in the absence of markers of myeloid clonality. Such a pathogenic clonal marker has now been identified as a somatic activating mutation of CSF3R, most commonly CSF3R T618I, thus demanding revision of the current WHO diagnostic classification to include the molecular criterion of mutated CSF3R. The clinical presentation, disease course and prognosis of CSF‐R mutated CNL have been recently outlined. Co‐operative mutations in SETBP1 and ASXL1 appear to be of prognostic significance and correlate with disease progression. Advances in the understanding of the molecular pathogenesis of CNL, have not yet fully translated into satisfactory therapeutic strategies, but the foundations for these are strengthening. Am. J. Hematol. 91:342–349, 2016. © 2015 Wiley Periodicals, Inc.

Colony stimulating factor 3 receptor gene (CSF3R) mutations have recently been associated with chronic neutrophilic leukemia (CNL). Fourteen patients with CSF3R‐mutated CNL (median age 67 years; 57% males) were screened for additional mutations; 8 (57%) and 5 (38%) harbored an ASXL1 and/or SETBP1 mutation (two patients expressed both), respectively. Two patients developed blastic transformation, both SETBP1‐mutated and ASXL1‐unmutated, whereas two other cases evolved into chronic myelomonocytic leukemia (CMML), both ASXL1‐mutated and SETBP1‐unmutated. Median survival was 23.2 months (10 deaths documented). On multivariable analysis mutated ASXL1 (P = 0.009; HR 19.6, 95% CI 2.1–184.1) and thrombocytopenia (P = 0.005; HR 28.8, 95% CI 2.8–298.2) were independently predictive of shortened survival. This study provides information on the natural history of CSF3R‐mutated CNL and identifies mutant ASXL1 and thrombocytopenia as risk factors for survival. The study also suggests pathogenetic roles for SETBP1 and ASXL1 mutations in disease evolution into blast phase disease and CMML, respectively. Am. J. Hematol. 90:653–656, 2015. © 2015 Wiley Periodicals, Inc.