Swapna Thota

Genetic alterations of the cohesin complex genes in myeloid malignancies.

Somatic cohesin mutations have been reported in myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). To account for the morphologic and cytogenetic diversity of these neoplasms, a well-annotated cohort of 1060 patients with myeloid malignancies including MDS (n = 386), myeloproliferative neoplasms (MPNs) (n = 55), MDS/MPNs (n = 169), and AML (n = 450) were analyzed for cohesin gene mutational status, gene expression, and therapeutic and survival outcomes. Somatic cohesin defects were detected in 12% of patients with myeloid malignancies, whereas low expression of these genes was present in an additional 15% of patients. Mutations of cohesin genes were mutually exclusive and mostly resulted in predicted loss of function. Patients with low cohesin gene expression showed similar expression signatures as those with somatic cohesin mutations. Cross-sectional deep-sequencing analysis for clonal hierarchy demonstrated STAG2, SMC3, and RAD21 mutations to be ancestral in 18%, 18%, and 47% of cases, respectively, and each expanded to clonal dominance concordant with disease transformation. Cohesin mutations were significantly associated with RUNX1, Ras-family oncogenes, and BCOR and ASXL1 mutations and were most prevalent in high-risk MDS and secondary AML. Cohesin defects were associated with poor overall survival (27.2 vs 40 months; P = .023), especially in STAG2 mutant MDS patients surviving >12 months (median survival 35 vs 50 months; P = .017).

Dynamics of clonal evolution in myelodysplastic syndromes

To elucidate differential roles of mutations in myelodysplastic syndromes (MDS), we investigated clonal dynamics using whole-exome and/or targeted sequencing of 699 patients, of whom 122 were analyzed longitudinally. Including the results from previous reports, we assessed a total of 2,250 patients for mutational enrichment patterns. During progression, the number of mutations, their diversity and clone sizes increased, with alterations frequently present in dominant clones with or without their sweeping previous clones. Enriched in secondary acute myeloid leukemia (sAML; in comparison to high-risk MDS), FLT3, PTPN11, WT1, IDH1, NPM1, IDH2 and NRAS mutations (type 1) tended to be newly acquired, and were associated with faster sAML progression and a shorter overall survival time. Significantly enriched in high-risk MDS (in comparison to low-risk MDS), TP53, GATA2, KRAS, RUNX1, STAG2, ASXL1, ZRSR2 and TET2 mutations (type 2) had a weaker impact on sAML progression and overall survival than type-1 mutations. The distinct roles of type-1 and type-2 mutations suggest their potential utility in disease monitoring.

Immune thrombocytopenia in adults: an update.

Immune thrombocytopenia (ITP) in adults is a chronic disease resulting from increased platelet destruction and impaired platelet production. Splenectomy remains the most effective and durable treatment in cases that are refractory to first-line therapy, but its use has declined because of the availability of alternate medical therapy, the associated risk of infection, and concern for surgeryrelated complications. Rituximab (Rituxan) may be an effective alternative but carries the risk of immunosuppression. Management has changed in the last decade, with new drugs and with increased awareness of treatment side effects.

Clinical and biological implications of ancestral and non-ancestral IDH1 and IDH2 mutations in myeloid neoplasms

Mutations in isocitrate dehydrogenase 1/2 (IDH1/2MT) are drivers of a variety of myeloid neoplasms. As they yield the same oncometabolite, D-2-hydroxyglutarate, they are often treated as equivalent, and pooled. We studied the validity of this approach and found IDH1/2 mutations in 179 of 2119 myeloid neoplasms (8%). Cross-sectionally, the frequencies of these mutations increased from lower- to higher risk disease, thus suggesting a role in clinical progression. Variant allelic frequencies indicated that IDH1MT and IDH2MT are ancestral in up to 14/74 (19%) vs 34/99 (34%; P=0.027) of cases, respectively, illustrating the pathogenic role of these lesions in myeloid neoplasms. IDH1/2MT was associated with poor overall survival, particularly in lower risk myelodysplastic syndromes. Ancestral IDH1MT cases were associated with a worse prognosis than subclonal IDH1MT cases, whereas the position of IDH2MT within clonal hierarchy did not impact survival. This may relate to distinct mutational spectra with more DNMT3A and NPM1 mutations associated with IDH1MT cases, and more ASXL1, SRSF2, RUNX1, STAG2 mutations associated with IDH2MT cases. Our data demonstrate important clinical and biological differences between IDH1MT and IDH2MT myeloid neoplasms. These mutations should be considered separately as their differences could have implications for diagnosis, prognosis and treatment with IDH1/2MT inhibitors of IDH1/2MT patients.

A Clinical Review of Small-Cell Carcinoma of the Urinary Bladder

Small-cell carcinoma of the urinary bladder is a rare and aggressive type of bladder cancer that has a poor prognosis. The incidence has been gradually increasing because of the aging population. Owing to its rarity there are no available treatment guidelines. Several retrospective studies and 1 prospective study have provided some insight into therapy for this disease. A multimodal approach that includes chemotherapy, local radiation therapy, and definitive surgery in resectable cases appears to be an optimal management approach.

Inotuzumab ozogamicin in relapsed B-cell acute lymphoblastic leukemia

Despite an improved understanding of disease biology and the use of multi‐agent chemotherapy, the long‐term survival of adults with B‐cell acute lymphoblastic leukemia (B‐ALL) ranges from 35% to 50%. Management of patients with relapsed B‐ALL, a group characterized by dismal outcomes, poses a clinical challenge. To address this unmet need, novel therapeutics are being investigated in the setting of relapsed B‐ALL with encouraging results. CD22 is an important B‐cell antigen expressed in 80‐90% of B‐ALL cases. CD22 undergoes constitutive endocytosis with antibody ligation, making it an attractive biologic target for immunoconjugates. Inotuzumab ozogamicin (IO), a CD22‐targeted antibody‐drug conjugate demonstrated impressive single agent activity even among heavily pretreated relapsed B‐ALL patients. A recent randomized phase III clinical trial demonstrates superiority of IO over standard of care chemotherapy as first‐ or second‐line salvage therapy for relapsed B‐ALL. In this review, we summarize the preclinical and clinical data available to date using IO in relapsed B‐ALL.

Genomic determinants of chronic myelomonocytic leukemia

The biology, clinical phenotype and progression rate of chronic myelomonocytic leukemia (CMML) are highly variable due to diverse initiating and secondary clonal genetic events. To determine the effects of molecular features including clonal hierarchy in CMML, we studied whole-exome and targeted next-generation sequencing data from 150 patients with robust clinical and molecular annotation assessed cross-sectionally and at serial time points of disease evolution. To identify molecular lesions unique to CMML, we compared it to the related myeloid neoplasms (N=586), including juvenile myelomonocytic leukemia, myelodysplastic syndromes (MDS) and primary monocytic acute myeloid leukemia and discerned distinct molecular profiles despite similar pathomorphological features. Within CMML, mutations in certain pathways correlated with clinical classification, for example, proliferative vs dysplastic features. While most CMML patients (59%) had ancestral (dominant/co-dominant) mutations involving TET2, SRSF2 or ASXL1 genes, secondary subclonal hierarchy correlated with clinical phenotypes or outcomes. For example, progression was associated with acquisition of new expanding clones carrying biallelic TET2 mutations or RAS family, or spliceosomal gene mutations. In contrast, dysplastic features correlated with mutations usually encountered in MDS (for example, SF3B1 and U2AF1). Classification of CMML based on hierarchies of ancestral and subclonal mutational events may correlate strongly with clinical features and prognosis.

Tofacitinib as a novel salvage therapy for refractory T-cell large granular lymphocytic leukemia

Tofacitinib as a novel salvage therapy for refractory T-cell large granular lymphocytic leukemia

Complete mutational spectrum of the autophagy interactome: a novel class of tumor suppressor genes in myeloid neoplasms

Complete mutational spectrum of the autophagy interactome: a novel class of tumor suppressor genes in myeloid neoplasms

Molecular features of early onset adult myelodysplastic syndrome

Myelodysplastic syndromes are typically diseases of older adults. Patients in whom the onset is early may have distinct molecular and clinical features or reflect a demographic continuum. The identification of differences between “early onset” patients and those diagnosed at a traditional age has the potential to advance understanding of the pathogenesis of myelodysplasia and may lead to formation of distinct morphological subcategories. We studied a cohort of 634 patients with various subcategories of myelodysplastic syndrome and secondary acute myeloid leukemia, stratifying them based on age at presentation and clinical parameters. We then characterized molecular abnormalities detected by next-generation deep sequencing of 60 genes that are commonly mutated in myeloid malignancies. The number of mutations increased linearly with age and on average, patients >50 years of age had more mutations. TET2, SRSF2, and DNMT3A were more commonly mutated in patients >50 years old compared to patients ≤50 years old. In general, patients >50 years of age also had more mutations in spliceosomal, epigenetic modifier, and RAS gene families. Although there are age-related differences in molecular features among patients with myelodysplasia, most notably in the incidence of SRSF2 mutations, our results suggest that patients ≤50 years old belong to a disease continuum with a distinct pattern of early onset ancestral events.