Key Points• This is the first study to validate the importance of NOTCH1 and SF3B1 gene mutations in the context of a randomized, prospective clinical trial.• Mutations in both genes are independent prognostic biomarkers, and therefore have clinical utility in the accurate risk-adapted stratification of CLL patients. Continuing Medical Education onlineThis activity has been planned and implemented in accordance with the Essential Areas and policies of the Accreditation Council for Continuing Medical Education through the joint sponsorship of Medscape, LLC and the American Society of Hematology. Medscape, LLC is accredited by the ACCME to provide continuing medical education for physicians. Medscape, LLC designates this Journal-based CME activity for a maximum of 1.0 AMA PRA Category 1 Credit(s) ™ . Physicians should claim only the credit commensurate with the extent of their participationin the activity. All other clinicians completing this activity will be issued a certificate of participation. To participate in this journal CME activity: (1) review the learning objectives and author disclosures; (2) study the education content; (3) take the post-test with a 70% minimum passing score and complete the evaluation at http://www.medscape.org/journal/blood; and (4) view/print certificate. For CME questions, see page 566. Disclosures Associate Editor John G. Gribben served as an advisor or consultant for Celgene and Roche and as a speaker or a member of a speakers bureau for Roche, Jensen, and Celgene. The authors and CME questions author Laurie Barclay, freelance writer and reviewer, Medscape, LLC, declare no competing financial interests. For personal use only. on May 9, 2018. by guest www.bloodjournal.org From Continuing Medical Education online Learning objectivesUpon completion of this activity, participants will be able to:1. Describe the frequency of NOTCH1 and SF3B1 mutations in patients with chronic lymphocytic leukemia (CLL), and their correlations with other genetic markers.2. Describe survival in CLL patients with NOTCH1 mutations, and the prognostic value of this mutation. 3. Describe survival in CLL patients with SF3B1 mutations, and the prognostic value of this mutation.

To identify novel risk variants for chronic lymphocytic leukemia (CLL) we conducted a genome-wide association study of 299,983 tagging SNPs, with validation in four additional series totaling 2,503 cases and 5,789 controls. We identified four risk loci for CLL at 2q37.3 (rs757978, FARP2; odds ratio [OR] = 1.39; P = 2.11 x 10-9), 8q24.21 (rs2456449; OR = 1.26; P = 7.84 x 10-10), 15q21.3 (rs7169431; OR = 1.36; P = 4.74 x 10-7) and 16q24.1 (rs305061; OR = 1.22; P = 3.60 x 10-7). There was also evidence for risk loci at 15q25.2 (rs783540, CPEB1; OR = 1.18; P = 3.67 x 10-6) and 18q21.1 (rs1036935; OR = 1.22; P = 2.28 x 10-6). These data provide further evidence for genetic susceptibility to this B-cell hematological malignancy.

Purpose: Mounting evidence supports the clinical significance of gene mutations and immunogenetic features in common mature B-cell malignancies.Experimental Design: We undertook a detailed characterization of the genetic background of splenic marginal zone lymphoma (SMZL), using targeted resequencing and explored potential clinical implications in a multinational cohort of 175 patients with SMZL.Results: We identified recurrent mutations in TP53 (16%), KLF2 (12%), NOTCH2 (10%), TNFAIP3 (7%), MLL2 (11%), MYD88 (7%), and ARID1A (6%), all genes known to be targeted by somatic mutation in SMZL. KLF2 mutations were early, clonal events, enriched in patients with del(7q) and IGHV1-2 Ã 04 B-cell receptor immunoglobulins, and were associated with a short median time to first treatment (0.12 vs. 1.11 years; P ¼ 0.01).In multivariate analysis, mutations in NOTCH2 [HR, 2.12; 95% confidence interval (CI), 1.02-4.4; P ¼ 0.044] and 100% germline IGHV gene identity (HR, 2.19; 95% CI, 1.05-4.55; P ¼ 0.036) were independent markers of short time to first treatment, whereas TP53 mutations were an independent marker of short overall survival (HR, 2.36; 95 % CI, 1.08-5.2; P ¼ 0.03). Conclusions:We identify key associations between gene mutations and clinical outcome, demonstrating for the first time that NOTCH2 and TP53 gene mutations are independent markers of reduced treatment-free and overall survival, respectively.

Purpose: The HOX genes comprise a large family of homeodomain-containing transcription factors, present in four separate clusters, which are key regulators of embryonic development, hematopoietic differentiation, and leukemogenesis. We aimed to study the role of DNA methylation as an inducer of HOX gene silencing in leukemia. Experimental Design: Three hundred and seventy-eight samples of myeloid and lymphoid leukemia were quantitatively analyzed (by COBRA analysis and pyrosequencing of bisulfitemodified DNA) for methylation of eight HOXA and HOXB cluster genes. The biological significance of the methylation identified was studied by expression analysis and through re-expression of HOXA5 in a chronic myeloid leukemia (CML) blast crisis cell line model. Results: Here, we identify frequent hypermethylation and gene inactivation of HOXA and HOXB cluster genes in leukemia. In particular, hypermethylation of HOXA4 and HOXA5 was frequently observed (26-79%) in all types of leukemias studied. HOXA6 hypermethylation was predominantly restricted to lymphoid malignancies, whereas hypermethylation of other HOXA and HOXB genes was only observed in childhood leukemia. HOX gene methylation exhibited clear correlations with important clinical variables, most notably in CML, in which hypermethylation of both HOXA5 (P = 0.00002) and HOXA4 (P = 0.006) was strongly correlated with progression to blast crisis. Furthermore, re-expression of HOXA5 in CML blast crisis cells resulted in the induction of markers of granulocytic differentiation. Conclusion: We propose that in addition to the oncogenic role of some HOX family members, other HOX genes are frequent targets for gene inactivation and normally play suppressor roles in leukemia development.

The combination of 11q deletion and ATM mutation in CLL is associated with significantly shorter progression-free and overall survival following first-line treatment with alkylating agents and purine analogs. Assessment of ATM mutation status in patients with 11q deletion may influence the choice of subsequent therapy.