Search

Allogenic hematopoietic cell transplantation (alloHCT) is a well-established curative modality for acute lymphoblastic leukemia (ALL), yet large amounts of data describing alloHCT outcomes in Philadelphia (Ph)-like ALL are lacking. We retrospectively analyzed archived DNA samples from consecutive adults with B-cell Ph-negative ALL who underwent alloHCT in complete remission (CR) (n = 127) at our center between 2006 and 2020. Identification of fusions associated with Ph-like ALL was performed using cumulative results from RNA-seq, conventional cytogenetics, fluorescence in situ hybridization, and whole genome array studies. Fusions associated with Ph-like ALL were detected in 56 (44%) patients, of whom 38 were carrying CRLF2r. Compared with other non–Ph-like ALL (n = 71), patients with fusions associated with Ph-like ALL were more frequently Hispanic (P = .008), were less likely to carry high-risk cytogenetics (P < .001), and were more likely to receive blinatumomab prior to HCT (P = .019). With the median followup of 3.5 years, patients with Ph-like ALL fusions had comparable posttransplant outcomes compared with other B-cell ALL: 3-year relapse-free survival (RFS) (41% vs 44%; P = .36), overall survival (OS) (51% vs 50%; P = .59), and relapse (37% vs 31%; P = .47). In multivariable analysis, age (P = .023), disease status at the time of transplant (P < .001), and donor type (P = .015) influenced OS. RFS (primary endpoint) was significantly influenced by disease status (P < .001) and conditioning regimen intensity (P = .014). In conclusion, our data suggest that alloHCT consolidation results in similarly favorable survival outcomes in adult patients with Ph-like fusions and other high-risk B-cell ALL.

Background Mutations in isocitrate dehydrogenase (IDH)1/2 genes result in nicotinamide adenine dinucleotide phosphate-dependent reduction of α-ketoglutarate and formation of 2-hydroxyglutarate, which blocks normal cellular differentiation and promotes leukemogenesis. Nearly 20% of acute myeloid leukemia (AML) patients carry IDH1/2 mutations. Although multiple investigators have described the prognostic implications of IDH mutations in AML patients receiving chemotherapy, the effect of these mutations on outcomes after allogeneic (allo) hematopoietic cell transplantation (HCT) is unknown. Patients and Methods We report on the clinical outcome of a cohort of AML patients, who were tested for IDH mutations and underwent alloHCT at City of Hope (2015-2017). Of a total of 317 screened patients, 99 (31%) underwent alloHCT, of whom 23 carried and 76 did not carry IDH mutations (control). Results No statistical significance was detected in patient’s overall survival (P = .84). With a median follow-up of 7.8 months, 1-year relapse rate of 29% and 13% was seen in the IDH-mutated and control group, respectively (P = .033). IDH1/2 mutation status remained significantly associated with relapse (hazard ratio, 2.8; P = .046) after inclusion of pre-HCT disease status in a multivariable model. Conclusion Our results, despite low patient numbers, indicate that IDH mutations are associated with higher relapse rate after alloHCT. Further prospective studies on post transplantation IDH inhibition is required to improve outcomes in AML patients who carry IDH mutations.

Background: Similar to poorly differentiated thyroid carcinoma (PDTC), papillary thyroid carcinoma with high-grade features (PTC HGF) demonstrates increased mitotic activity and/or necrosis; howeve...

Philadelphia chromosome-like acute lymphoblastic leukemia (Ph-like ALL) represents 20% of newly diagnosed adults with B cell ALL (B-ALL), with increased frequency in adults with Hispanic ethnicity. Ph-like ALL harbors a diverse range of genetic alterations with CRLF2-rearrangement/overexpression (CRLF2r) being the most common one. When treated with chemotherapy, Ph-like ALL is associated with inferior response, high relapse rate, and low overall survival (OS). Allogenic hematopoietic cell transplantation (alloHCT) is a well-established curative modality for adults with high-risk ALL. Considering that Ph-like ALL is a high-risk leukemia subtype, it is appealing to recommend alloHCT consolidation routinely for this entity in adults. However, large datasets describing alloHCT outcomes in patients with Ph-like ALL is lacking. In this study, we retrospectively analyzed archived DNA samples from 125 consecutive adult patients with Ph-negative ALL who underwent alloHCT in complete remission (CR) at our center between 2006 and 2020. Classification of Ph-like versus non-Ph-like was performed according to WHO 2017 classification using accumulative results from RNAseq, conventional cytogenetics, FISH, and whole genome array studies. A proprietary RNA sequencing assay covering 1,188 genomic regions from 235 genes was designed to detect all the clinically significant fusions and expressions for Ph-like ALLs. In addition, an algorithm employing the RNAseq data was developed to further aid in classification of Ph-like ALL. Boruta feature selection (R package "Boruta" version 7.0.0) was used to identify the most informative genes for prediction with an out-of-bag error of 9.62%. The following 24 genes were identified: CCND2, SOX11, PAX5, DENND3, RARA, MME, ID4, SH3BP5, HOXA9, CA6, MUC4, CYB5R2, CD97, EPOR, IL2RA, RAB29, PDGFRA, MLLT4, RHOA, JAK2, DNM2, ASXL1, BCL2A1, and KDR. The results were used to predict Ph-like status by a Random Forest model (R package "randomForest" version 4.6-14) that generates a probability/similarity score of Ph gene expression profile (Ph score). The testing samples with Ph score over 50% and without other subtype-defining lesions are defined as Ph-like. We identified Ph-like genetic alterations in 66 (53%) patients, of whom 42 (66%) were carrying CRLF2r and 24 (36%) were non-CRLF2r. Compared to non-Ph-like ALL (n=59), Ph-like ALL patients were younger (42 vs 36 years old, p=0.022), more frequently Hispanic (56% vs 83%, p=0.003), less frequently carried high-risk cytogenetics (39% vs 9%, p1 regimen to achieve their first complete remission (CR1; 30% vs 55%, p=0.025). However, we did not detect any significant difference between the two groups in disease status (CR1 vs. CD2/3; p=0.81) or minimal residual disease clearance at the time of HCT (negative vs. positive; p=0.17), donor type (match related/unrelated vs mismatch vs haplo vs cord blood; p=0.88), conditioning regimen intensity (myeloablative vs non-myeloablative/ reduced intensity; p=0.59), GVHD prophylaxis (tacrolimus/sirolimus-based vs PTCy-based; p=0.84), Karnofsky Performance Status (KPS; p=0.24) or HCT comorbidity index (0 vs 1-2 vs >2; p=0.42). With the median follow-up of 3.2 years, we observed similar 3-years leukemia-free survival (LFS) (40% vs 47%; p=0.95), OS (44% vs 54%; p=0.96), relapse rate (33% vs 34%; p=0.96) and non-relapse mortality (NRM) (27% vs 19%; p=0.92) between non-Ph-like and Ph-like ALL patients, respectively. (Figure) In multivariable analysis, disease status at the time of HCT (HR=2.63, 95% CI: 1.57-4.41; p In conclusion, our data suggest that alloHCT consolidation results in favorable outcomes in adult patients with Ph-like ALL with comparable outcomes to non-Ph-like ALL. Our data support utilization of alloHCT for adults with Ph-like ALL in CR. Figure 1 Figure 1. Disclosures Al Malki: Neximmune: Consultancy; Rigel Pharma: Consultancy; Jazz Pharmaceuticals, Inc.: Consultancy; Hansa Biopharma: Consultancy; CareDx: Consultancy. Khaled: Omeros: Honoraria; Alexion: Honoraria, Speakers Bureau; Janssen: Current Employment; Astellas: Honoraria; Jazz: Honoraria. Ali: Incyte: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; BMS: Speakers Bureau; CTI BioPharma: Membership on an entity's Board of Directors or advisory committees. Aribi: Seagen: Consultancy. Mei: BMS: Research Funding; Epizyme: Research Funding; TG Therapeutics: Research Funding; EUSA: Honoraria; Janssen: Honoraria; Morphosys: Research Funding; Beigene: Research Funding. Koller: Novartis: Consultancy. Artz: Radiology Partners: Other: Spouse has equity interest in Radiology Partners, a private radiology physician practice. Stein: Amgen: Consultancy, Speakers Bureau; Celgene: Speakers Bureau; Stemline: Speakers Bureau. Marcucci: Abbvie: Other: Speaker and advisory scientific board meetings; Novartis: Other: Speaker and advisory scientific board meetings; Agios: Other: Speaker and advisory scientific board meetings. Forman: Lixte Biotechnology: Consultancy, Current holder of individual stocks in a privately-held company; Mustang Bio: Consultancy, Current holder of individual stocks in a privately-held company; Allogene: Consultancy. Pullarkat: AbbVie, Amgen, Genentech, Jazz Pharmaceuticals, Novartis, Pfizer, and Servier: Membership on an entity's Board of Directors or advisory committees; Amgen, Dova, and Novartis: Consultancy, Honoraria.

Therapy-related myelodysplastic syndrome is a long-term complication of cancer treatment in patients receiving cytotoxic therapy, characterized by high-risk genetics and poor outcomes. Allogeneic hematopoietic cell transplantation is the only potential cure for this disease, but the prognostic impact of pre-transplant genetics and clinical features has not yet been fully characterized. We report here the genetic and clinical characteristics and outcomes of a relatively large cohort of patients with therapy-related myelodysplastic syndrome (n=67) who underwent allogeneic transplantation, comparing these patients to similarly treated patients with de novo disease (n=199). The 5-year overall survival was not different between patients with therapy-related and de novo disease (49.9% versus 53.9%; P=0.61) despite a higher proportion of individuals with an Intermediate-2/High International Prognostic Scoring System classification (59.7% versus 43.7%; P=0.003) and high-risk karyotypes (61.2% versus 30.7%; P

The goal of this study is to characterize the genomic and immune profiles of metaplastic breast cancer (MpBC) and identify the association with survival through an analysis of archived tumor tissue. A next-generation sequencing-based mutational assay (Onco-48) was performed for 21 MpBC patients. Clinicopathologic characteristics were captured, including relapse free survival (RFS) and overall survival (OS). Immunohistochemistry (IHC) for CD3, CD4, CD8, and programmed death-ligand 1 (PD-L1) was also performed. Recurrence free survival (RFS) at 5 years was 57% (95% CI 0.34-0.75) and overall survival (OS) at 5 years was 66% (95% CI 0.41-0.82). The most commonly altered genes were TP53 (68.4%, 13/19), PIK3CA (42.1%, 8/19), and PTEN (15.8%, 3/19. For patients with PIK3CA mutations, RFS and OS were significantly worse than for those without (HR 5.6, 95% CI 1.33-23.1 and HR 8.0, 95% CI 1.53-41.7, respectively). Cox regression estimated that PD-L1 expression was associated with worse RFS and OS (HR 1.08, 95% CI 1.01-1.16 and HR 1.05, 95% CI 1.00-1.11, respectively, for an absolute increase in PD-L1 expression of 1%). In conclusion, PIK3CA mutation and PD-L1 expression confer poor prognosis in this cohort of patients with MpBC.

7559 Background: Chronic myelomonocytic leukemia (CMML) has features of both a myeloproliferative neoplasm and a myelodysplastic syndrome. The median overall survival (OS) in most series is 20-40 months. CMML is a relatively rare entity, and there is limited understanding of prognostic molecular markers. CMML associated with bone marrow fibrosis grade 1, appear to have shorter progression free survival. In this study we investigated the correlation of mutations with bone marrow reticulin fibrosis in patients with CMML. Methods: We investigated a cohort of 41 consecutive patients diagnosed with CMML 0, 1, 2, and CMML-AML from 2014 to 2019 at our institute. The median age of 41 patients was 68 years (range, 34-82). 27% were females and 73% were males. This cohort consists of 8 (20%) patients with CMML0, 19 (46%) with CMML1, 8 (20%) with CMML2 and 6 (15%) with CMML-AML. Genomic DNA was extracted from the bone marrow aspirates and targeted mutation NGS libraries were prepared from 200 ng of genomic DNA using the SureSelect target enrichment system (Agilent Technologies Inc.). The gene panel consists of 73 genes focused on myeloid neoplasms. The data were curated on the basis of our molecular pathology and national databases. Additionally, clinical data and bone marrow (BM) reticulin fibrosis grades (n = 27 available) were retrieved from the patient’s medical record. Results: The mutational profile frequency in our cohort showed that the most common mutations were TET2 (31%), ASXL1 (31%), and SRSF2 (23%), with frequencies very similar to those reported in the literature. Of the 27 cases with an available reticulin stain, only low grade fibrosis (MF-0, n = 18. MF-1, n = 9) were identified in our cohort. The frequencies of mutations in ASXL1, U2AF1, TP53, JAK2 and RUNX1, positively correlated with low grade fibrosis (MF-1). Additionally, patients with higher frequencies of SRSF2, TET2, and SETBP1 mutations showed no fibrosis (MF-0). Conclusions: This study is the first to correlate the degree of fibrosis with the frequency of mutations in CMML. We found similar mutations spectrum reported in the literature in patients with CMML. The mutational profile associated with CMML cases appears to affect the degree of the bone marrow fibrosis at the time of diagnosis.

1509 Background: Clonal hematopoiesis (CH) in myeloid related-genes is associated with development of primary and secondary leukemia and atherosclerotic disease, as well as, decreased overall survival. Identification of factors beyond age and cytotoxic exposures that predispose to CH may be useful to both recognize individuals at increased risk for CH and to better understand how CH develops. We have previously shown that germline mutations in the DNA repair gene ATM may predispose to CH. We hypothesized here that heterozygous ATM germline mutation carriers would have higher rates of CH in myeloid genes compared to controls. Methods: Germline DNA samples from 34 heterozygous ATM germline mutation carriers (cases) and 22 controls without ATM germline mutations were sequenced on an Illumina 2500 using a custom 79-gene-myeloid-CH-coding-exon-amplicon-based Qiaseq panel. Read depth averaged 130x. Pathogenic and likely pathogenic CH variants (PV) above an allele fraction of 2% were used for analyses. Cases and controls were compared using a rank-sum test. Results: Cases had a higher median age (56 years, range 30-82) than controls (48 years, range 5-72). Cases and controls were similar in solid tumor cancer history and known exposure to cancer cytotoxic therapy; 73.5% vs 86.4%, and 18.1 vs 20.6%, respectively. The number of CH PV was similarly associated with age in both cases and controls (cor = 0.31, p = 0.01). Cases displayed more CH PVs than controls (total 62 vs 3 PVs, median 2 PVs vs 0, p = 10-6). Of note, cases frequently had a concomitant second (n = 10; 29% of cases) or third (n = 4; 11.8% of cases) unique ATM CH PV, whereas no ATM CH PVs were seen in controls. Even after excluding ATM CH PVs, CH PVs were more frequent in cases (p = 0.00003). After ATM CH PVs, the most frequent CH PVs in cases were in NF1 (5 PVs), BCORL1 (4 PVs), and DMNT3A (4 PVs). Conclusions: Our study supports ATM as a strong predisposition locus for myeloid gene CH. CH in ATM germline mutation carriers frequently involved unique low allele fraction PVs in ATM, suggesting ATM germline PVs are driving production of likely bi-allelic ATM inactivation in white blood cells, or complete ATM loss. Complete ATM loss may be a nidus particularly for lymphocytic leukemia, as bi-allelic ATM inactivation is a frequent somatic finding.

AIM: To investigate the impact of RAS and BRAF mutations on the pattern of metastatic disease and carcinoembryonic antigen (CEA) production. METHODS: In this retrospective study, we investigated the impact of RAS and BRAF mutational status on pattern of metastatic disease and CEA production. Only patients presenting with a newly diagnosed metastatic colorectal cancer (CRC) were included. Patients’ characteristics, primary tumor location, site of metastatic disease and CEA at presentation were compared between those with and without RAS and BRAF mutations. RESULTS: Among 174 patients, mutations in KRAS, NRAS and BRAF were detected in 47%, 3% and 6% respectively. RAS mutations (KRAS and NRAS) were more likely to be found in African American patients (87% vs 13%; P value = 0.0158). RAS mutations were associated with a higher likelihood of a normal CEA (< 5 ng/mL) at presentation. BRAF mutations were more likely to occur in females. We were not able to confirm any association between mutational status and site of metastatic disease at initial diagnosis. CONCLUSION: No association was found between RAS and BRAF mutations and sites of metastatic disease at the time of initial diagnosis in our cohort. Patients with RAS mutations were more likely to present with CEA levels < 5 ng/mL. These findings may have clinical implications on surveillance strategies for RAS mutant patients with earlier stages of CRC.

e23131Background: The O6-methylguanine methyltransferase (MGMT) is a DNA repair enzyme that is responsible for de-alkylation of naturally occurring O6-methylguanines in DNA and aids in the preventi...