Fluorescent In Situ Hybridization for TP53 in the Diagnosis of Pediatric Osteogenic Sarcoma
AMERICAN JOURNAL OF SURGICAL PATHOLOGY
Authors: Marrano, Paula; Shago, Mary; Somers, Gino R.; Thorner, Paul S.
Abstract
Osteogenic sarcoma (OS) is the most common malignant bone tumor in children and adolescents. Despite advances in molecular genetic characterization of pediatric and adult tumors, the diagnosis of OS still depends almost entirely on light microscopy. The lack of consistent genetic changes in OS has greatly hindered the development of any diagnostic molecular test. Recently, whole-genome sequencing has shown that similar to 50% of cases of OS have a translocation involving the TP53 gene with breakpoints confined to the first intron. We developed a 2 color break-apart fluorescent in situ hybridization (FISH) probe for intron 1 of TP53 and applied it to an archived series to assess its diagnostic utility. The study group included 37 cases of OS (including osteoblastic, chondroblastic, and fibroblastic), as well as 53 cases of non-OS pediatric sarcomas (including Ewing sarcoma, rhabdomyosarcoma, undifferentiated small cell sarcoma, CCNB3-BCOR sarcoma, CIC-DUX sarcoma, synovial sarcoma, and malignant peripheral nerve sheath tumor) and 27 cases of benign bone lesions (including osteoblastoma, chondromyxoid fibroma, fibrous dysplasia, and fibro-osseous dysplasia). A rearranged signal was found in 20/37 cases (54%) of OS and in none of the other sarcomas or benign bone lesions, giving the FISH test 100% specificity for a diagnosis of OS. p53 immunostaining was generally not predictive of the results obtained by FISH and could not substitute for this test. This FISH probe offers a simple and specific genetic test to aid in the diagnosis of OS, despite the genetic complexity of this tumor.
Additional gene mutations may refine the 2017 European LeukemiaNet classification in adult patients with de novo acute myeloid leukemia aged < 60 years
LEUKEMIA
Authors: Eisfeld, Ann-Kathrin; Kohlschmidt, Jessica; Mims, Alice; Nicolet, Deedra; Walker, Christopher J.; Blachly, James S.; Carroll, Andrew J.; Papaioannou, Dimitrios; Kolitz, Jonathan E.; Powell, Bayard E.; Stone, Richard M.; de la Chapelle, Albert; Byrd, John C.; Mrozek, Krzysztof; Bloomfield, Clara D.
Abstract
The European LeukemiaNet (ELN) recommendations for diagnosis and management of acute myeloid leukemia (AML) have become an important tool to assess patients' prognosis and guide treatment. We tested the prognostic impact of the 2017 ELN classification in a large cohort of 863 AML patients aged <60 years similarly treated on Cancer and Leukemia Group B/Alliance for Clinical Trials in Oncology studies. Based on multivariable models within each ELN genetic-risk group, we identified additional gene mutations that may refine the 2017 ELN risk classification.BCOR-orSETBP1-mutated favorable-risk patients with non-core-binding factor AML andIDH-mutated adverse-risk patients had intermediate-risk outcomes. Outcomes ofNPM1/WT1co-mutated patients and those ofZRSR2-mutated patients resembled outcome of adverse-risk patients. Moreover,FLT3-ITD(high)allelic ratio conferred adverse rather than intermediate-risk irrespective of theNPM1mutation status, andDNMT3Amutations associated with very poor survival. Application of these refinements reclassified 9% of current favorable-risk patients and 53% of current intermediate-risk patients to the adverse-risk group, with similar poor survival as current adverse-risk patients. Furthermore, 4% of current favorable-risk patients and 9% of adverse-risk patients were reclassified to the intermediate-risk group.