[A revised 4 edition WHO Classification of Tumors of Hematopoietic and Lymphoid Tissues, 2017: myeloid neoplasms]. / Peresmotrennaia Klassifikatsiia VOZ opukholei gemopoéticheskoi i limfoidnoi tkani, 2017 (4-e izdanie): mieloidnye neoplazii.

The paper presents new molecular data, the principles of the classification of myeloid neoplasms, and criteria for their diagnosis according to the new edition of the WHO Classification of Tumors of Hematopoietic and Lymphoid Tissues, 2017. Current concepts of clonal hematopoiesis and models of clonal evolution are presented to characterize the common features of the molecular pathogenesis of myeloid neoplasms. There are new data and general principles of diagnosis of myeloid neoplasms: Ph-negative myeloproliferative diseases, myelodysplastic syndromes, myeloid/lymphoid neoplasms with eosinophilia and rearrangements of PDGFRA, PDGFRB, FGFR1, and PCM1-JAK2, diseases from the group of myelodysplastic/myeloproliferative diseases. Emphasis is laid on the possibilities and limitations of pathological differential diagnosis when a pathologist examines bone marrow trepanobiopsy specimens in his/her routine work.

Whole-exome sequencing enhances prognostic classification of myeloid malignancies.

PURPOSE: To date the standard nosology and prognostic schemes for myeloid neoplasms have been based on morphologic and cytogenetic criteria. We sought to test the hypothesis that a comprehensive, unbiased analysis of somatic mutations may allow for an improved classification of these diseases to predict outcome (overall survival). EXPERIMENTAL DESIGN: We performed whole-exome sequencing (WES) of 274 myeloid neoplasms, including myelodysplastic syndrome (MDS, N=75), myelodysplastic/myeloproliferative neoplasia (MDS/MPN, N=33), and acute myeloid leukemia (AML, N=22), augmenting the resulting mutational data with public WES results from AML (N=144). We fit random survival forests (RSFs) to the patient survival and clinical/cytogenetic data, with and without gene mutation information, to build prognostic classifiers. A targeted sequencing assay was used to sequence predictor genes in an independent cohort of 507 patients, whose accompanying data were used to evaluate performance of the risk classifiers. RESULTS: We show that gene mutations modify the impact of standard clinical variables on patient outcome, and therefore their incorporation hones the accuracy of prediction. The mutation-based classification scheme robustly predicted patient outcome in the validation set (log rank P=6.77 × 10(-21); poor prognosis vs. good prognosis categories HR 10.4, 95% CI 3.21-33.6). The RSF-based approach also compares favorably with recently-published efforts to incorporate mutational information for MDS prognosis. CONCLUSION: The results presented here support the inclusion of mutational information in prognostic classification of myeloid malignancies. Our classification scheme is implemented in a publicly available web-based tool (http://myeloid-risk. CASE: edu/).

Genomic analysis of bone marrow failure and myelodysplastic syndromes reveals phenotypic and diagnostic complexity.

Accurate and timely diagnosis of inherited bone marrow failure and inherited myelodysplastic syndromes is essential to guide clinical management. Distinguishing inherited from acquired bone marrow failure/myelodysplastic syndrome poses a significant clinical challenge. At present, diagnostic genetic testing for inherited bone marrow failure/myelodysplastic syndrome is performed gene-by-gene, guided by clinical and laboratory evaluation. We hypothesized that standard clinically-directed genetic testing misses patients with cryptic or atypical presentations of inherited bone marrow failure/myelodysplastic syndrome. In order to screen simultaneously for mutations of all classes in bone marrow failure/myelodysplastic syndrome genes, we developed and validated a panel of 85 genes for targeted capture and multiplexed massively parallel sequencing. In patients with clinical diagnoses of Fanconi anemia, genomic analysis resolved subtype assignment, including those of patients with inconclusive complementation test results. Eight out of 71 patients with idiopathic bone marrow failure or myelodysplastic syndrome were found to harbor damaging germline mutations in GATA2, RUNX1, DKC1, or LIG4. All 8 of these patients lacked classical clinical stigmata or laboratory findings of these syndromes and only 4 had a family history suggestive of inherited disease. These results reflect the extensive genetic heterogeneity and phenotypic complexity of bone marrow failure/myelodysplastic syndrome phenotypes. This study supports the integration of broad unbiased genetic screening into the diagnostic workup of children and young adults with bone marrow failure and myelodysplastic syndromes.

Risk of marrow neoplasms after adjuvant breast cancer therapy: the national comprehensive cancer network experience.

PURPOSE: Outcomes for early-stage breast cancer have improved. First-generation adjuvant chemotherapy trials reported a 0.27% 8-year cumulative incidence of myelodysplastic syndrome/acute myelogenous leukemia. Incomplete ascertainment and follow-up may have underestimated subsequent risk of treatment-associated marrow neoplasm (MN). PATIENTS AND METHODS: We examined the MN frequency in 20,063 patients with stage I to III breast cancer treated at US academic centers between 1998 and 2007. Time-to-event analyses were censored at first date of new cancer event, last contact date, or death and considered competing risks. Cumulative incidence, hazard ratios (HRs), and comparisons with Surveillance, Epidemiology, and End Results estimates were obtained. Marrow cytogenetics data were reviewed. RESULTS: Fifty patients developed MN (myeloid, n = 42; lymphoid, n = 8) after breast cancer (median follow-up, 5.1 years). Patients who developed MN had similar breast cancer stage distribution, race, and chemotherapy exposure but were older compared with patients who did not develop MN (median age, 59.1 v 53.9 years, respectively; P = .03). Two thirds of patients had complex MN cytogenetics. Risk of MN was significantly increased after surgery plus chemotherapy (HR, 6.8; 95% CI, 1.3 to 36.1) or after all modalities (surgery, chemotherapy, and radiation; HR, 7.6; 95% CI, 1.6 to 35.8), compared with no treatment with chemotherapy. MN rates per 1,000 person-years were 0.16 (surgery), 0.43 (plus radiation), 0.46 (plus chemotherapy), and 0.54 (all three modalities). Cumulative incidence of MN doubled between years 5 and 10 (0.24% to 0.48%); 9% of patients were alive at 10 years. CONCLUSION: In this large early-stage breast cancer cohort, MN risk after radiation and/or adjuvant chemotherapy was low but higher than previously described. Risk continued to increase beyond 5 years. Individual risk of MN must be balanced against the absolute survival benefit of adjuvant chemotherapy.

From Janus kinase 2 to calreticulin: the clinically relevant genomic landscape of myeloproliferative neoplasms.

Our understanding of the genetic basis of myeloproliferative neoplasms began in 2005, when the JAK2 (V617F) mutation was identified in polycythemia vera, essential thrombocythemia, and primary myelofibrosis. JAK2 exon 12 and MPL exon 10 mutations were then detected in subsets of patients, and subclonal driver mutations in other genes were found to be associated with disease progression. Recently, somatic mutations in the gene CALR, encoding calreticulin, have been found in most patients with essential thrombocythemia or primary myelofibrosis with nonmutated JAK2 and MPL. The JAK-STAT pathway appears to be activated in all myeloproliferative neoplasms, regardless of founding driver mutations. These latter, however, have different effects on clinical course and outcomes. Thus, evaluation of JAK2, MPL, and CALR mutation status is important not only for diagnosis but also for prognostication. These genetic data should now also be considered in designing clinical trials.

Immunohistochemical analysis of hepatocyte growth factor and c-Met in plasma cell disease.

AIMS: Interaction with the bone marrow microenvironment is important for homing and survival of myeloma cells. One cytokine involved in this process is hepatocyte growth factor (HGF). HGF, by binding to the receptor tyrosine kinase c-Met, mediates a broad range of tumour progression activities. Our aims were to investigate whether HGF and c-Met are present in bone marrow and extramedullary tumours from patients with monoclonal plasma cell disease, and whether c-Met is activated. METHODS AND RESULTS: Expression of HGF, c-Met and phospho-c-Met was studied by immunohistochemistry in biopsies from 80 patients with monoclonal plasma cell disease. Cytoplasmic staining for HGF in plasma cells was demonstrated in 58 of 68 biopsies from multiple myeloma patients (85%), but also in biopsies from nine of 10 healthy individuals. Membranous staining for c-Met was found in 25 of 63 multiple myeloma patients (40%) and in none of 10 healthy individuals. Membranous staining for phospho-c-Met was found in biopsies from 15 of 21 c-Met-positive myeloma patients (71%). CONCLUSIONS: Our data point to c-Met expression as one of the factors that distinguishes normal from malignant plasma cells, and indicate that the HGF/c-Met system is activated in multiple myeloma patients.

Erythroid proliferations in myeloid neoplasms.

Prominent erythroid proliferations (in which erythroid elements comprise ≥50% of total bone marrow cells) can be seen in various hematopoietic stem cell neoplasms. The myeloproliferative neoplasm polycythemia vera exhibits effective, overexuberant erythropoiesis resulting in an increased red blood cell mass; in contrast, most other diseases characterized by erythroid predominance exhibit ineffective hemopoiesis. The latter include acute erythroid leukemia (erythroid-myeloid and pure erythroid leukemia subtypes) as well as some cases of myelodysplastic syndromes, acute myeloid leukemia with myelodysplasia-related changes, and therapy-related myeloid neoplasms. Some nonneoplastic reactive conditions may also manifest a striking bone marrow erythroid predominance. In this article, we review the literature relevant to this group of diseases for a better understanding of their clinicopathologic features and surrounding controversies. We also examine the position of neoplastic erythroid proliferations in the current 2008 World Health Organization Classification of Myeloid Neoplasms and provide recommendations as to how to approach the differential diagnosis of this group of diseases.

World health organization classification, evaluation, and genetics of the myeloproliferative neoplasm variants.

There is no single category in the fourth edition (2008) of the World Health Organization (WHO) classification of myeloid neoplasms that encompasses all of the diseases referred to by some authors as the myeloproliferative neoplasm (MPN) "variants." Instead, they are considered as distinct entities and are distributed among various subgroups of myeloid neoplasms in the classification scheme. These relatively uncommon neoplasms do not meet the criteria for any so-called "classical" MPN (chronic myelogenous leukemia, polycythemia vera, primary myelofibrosis, or essential thrombocythemia) and, although some exhibit myelodysplasia, none meets the criteria for any myelodysplastic syndrome (MDS). They are a diverse group of neoplasms ranging from fairly well-characterized disorders such as chronic myelomonocytic leukemia to rare and thus poorly characterized disorders such as chronic neutrophilic leukemia. Recently, however, there has been a surge of information regarding the genetic infrastructure of neoplastic cells in the MPN variants, allowing some to be molecularly defined. Nevertheless, in most cases, correlation of clinical, genetic, and morphologic findings is required for diagnosis and classification. The fourth edition of the WHO classification provides a framework to incorporate those neoplasms in which a genetic abnormality is a major defining criterion of the disease, such as those associated with eosinophilia and abnormalities of PDGFRA, PDGFRB, and FGFR1, as well as for those in which no specific genetic defect has yet been discovered and which remain clinically and pathologically defined. An understanding of the clinical, morphologic, and genetic features of the MPN variants will facilitate their diagnosis.

Presence of bone marrow micrometastasis is associated with different recurrence risk within molecular subtypes of breast cancer.

Expression profiles of primary breast tumors were investigated in relation to disseminated tumor cells (DTCs) in bone marrow (BM) in order to increase our understanding of the dissemination process. Tumors were classified into five pre-defined molecular subtypes, and presence of DTC identified (at median 85 months follow-up) a subgroup of luminal A patients with particular poor outcome (p=0.008). This was not apparent for other tumor subtypes. Gene expression profiles associated with DTC and with systemic relapse for luminal A patients were identified. This study suggests that DTC in BM differentially distinguishes clinical outcome in patients with luminal A type tumors and that DTC-associated gene expression analysis may identify genes of potential importance in tumor dissemination.

Fluorescence in situ hybridization analyses of chromosome band 1p36 in neuroblastoma detect two classes of alterations.

Chromosomal alterations in 1p36 were investigated in 196 neuroblastoma tumors using fluorescence in situ hybridization. Additionally, by using the same technique, it was determined whether MYCN was amplified in 149 of these. The most frequent finding was a deletion in 1p36, leading to monosomy of this region (29 cases, 15%). Furthermore, we found tumors with at least two intact copies of chromosome 1 and additional 1p36-deleted copies. Altogether, 21 tumors (11%) displayed this imbalance of 1p36. Similar to the cases with deletion, imbalances were predominantly found in stage 4 tumors (81%), and they were significantly associated with an increased patient age (P = 0.01). Nearly all 1p-deleted tumors showed amplification of MYCN (24/27 analyzed samples, 89%), whereas only 8 of 21 (38%) with imbalance did. Eight cases with imbalance were investigated for loss of heterozygosity (LOH) using microsatellite markers in 1p35-36. Only 4 displayed 1p36 LOH, whereas the remaining 4 were heterozygous. Both patients with deletion of 1p and with imbalance had a poor outcome [3-year rate of event-free-survival (EFS): 33 +/- 15% and 41 +/- 15%], which was significantly worse compared to the outcome of patients without 1p alterations (3-year EFS: 70 +/- 5%; P = 0.01 and P = 0.0059). We conclude that besides monosomic short arm deletions, imbalance of 1p36 is a strong marker of a poor prognosis in neuroblastoma and not necessarily associated with MYCN amplification and LOH.