Non-ossifying fibroma: A RAS-MAPK driven benign bone neoplasm
JOURNAL OF PATHOLOGY
Authors: Bovee, Judith V. M. G.; Hogendoorn, Pancras C. W.
Abstract
Non-ossifying fibroma (NOF) has been an intriguing entity since its first description. It is the most common bone tumour, is usually asymptomatic affecting children and adolescents, is composed of a heterogeneous cell population, and undergoes spontaneous regression after puberty. In a recent article in The Journal of Pathology, Baumhoer and colleagues demonstrate mutations activating the RAS-MAPK pathway (KRAS, FGFR1 and NF1) in similar to 80% of the tumours. Activation of the RAS-MAPK pathway by somatic mutations is found in a plethora of tumour types, both benign and malignant, while germline mutations cause a wide range of syndromes collectively termed the RASopathies. Their findings indicate that NOF, for long thought to be reactive, should be considered a true neoplasm. Moreover, their data suggest that only a subset of cells in the lesion contain the mutation. A second cell population consisting of histiocytes and osteoclast-like giant cells appears to be reacbenign and locally aggressive bone tumours and seems essential for tumourigenesis. The spontaneous regtive. This intimate relation between WT and mutant cells is also frequently encountered in other ression remains enigmatic and it is tempting to speculate that pubertal hormonal signalling, especially increased oestrogen levels, affect the balance between mutant and WT cells. (c) 2019 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.
Sorafenib and omacetaxine mepesuccinate as a safe and effective treatment for acute myeloid leukemia carrying internal tandem duplication of Fms-like tyrosine kinase 3
CANCER
Authors: Zhang, Chunxiao; Lam, Stephen S. Y.; Leung, Garret M. K.; Tsui, Sze-Pui; Yang, Ning; Ng, Nelson K. L.; Ip, Ho-Wan; Au, Chun-Hang; Chan, Tsun-Leung; Ma, Edmond S. K.; Yip, Sze-Fai; Lee, Harold K. K.; Lau, June S. M.; Luk, Tsan-Hei; Li, Wa; Kwong, Yok-Lam; Leung, Anskar Y. H.
Abstract
Background Omacetaxine mepesuccinate (OME) has antileukemic effects against acute myeloid leukemia (AML) carrying an internal tandem duplication of Fms-like tyrosine kinase 3 (FLT3-ITD). A phase 2 clinical trial was conducted to evaluate a combination treatment of sorafenib and omacetaxine mepesuccinate (SOME). Methods Relapsed or refractory (R/R) or newly diagnosed patients were treated with sorafenib (200-400 mg twice daily) and OME (2 mg daily) for 7 (first course) or 5 days (second course onward) every 21 days until disease progression or allogeneic hematopoietic stem cell transplantation (HSCT). The primary endpoint was composite complete remission, which was defined as complete remission (CR) plus complete remission with incomplete hematologic recovery (CRi). Secondary endpoints were leukemia-free survival (LFS) and overall survival (OS). Results Thirty-nine R/R patients and 5 newly diagnosed patients were recruited. Among the R/R patients, 28 achieved CR or CRi. Two patients showed partial remission, and 9 patients did not respond. Among the 5 newly diagnosed patients, 4 achieved CR, and 1 achieved CRi. The median LFS and OS were 5.6 and 10.9 months, respectively. Prior Fms-like tyrosine kinase 3 (FLT3) inhibitor exposure (P = .007), 2 or more inductions (P = .001), and coexisting IDH2 (P = .008) and RUNX1 mutations (P = .003) were associated with lower CR/CRi rates. HSCT consolidation and deep molecular responses (defined as an FLT3-ITD variant allelic frequency [VAF] <= 0.1% or a nucleophosmin 1 [NPM1] mutant VAF <= 0.01%) were associated with better OS and LFS. Prior FLT3 inhibitor exposure and 2 or more inductions were associated with inferior LFS. Conclusions SOME was safe and effective for R/R and newly diagnosed FLT3-ITD AML.