PURPOSE Adult T-cell leukemia/lymphoma (ATLL) is an aggressive disease caused by the human T-cell leukemia virus type 1. Real-world data of ATLL in Latin America are lacking. PATIENTS AND METHODS We analyzed patients with ATLL (acute, lymphomatous, chronic, and smoldering) encountered in 11 Latin American countries between 1995 and 2019. Treatment response was assessed according to the 2009 consensus report. Survival curves were estimated using the Kaplan-Meier method and log-rank test. RESULTS We identified 253 patients; 226 (lymphomatous: n = 122, acute: n = 73, chronic: n = 26, and smoldering: n = 5) had sufficient data for analysis (median age 57 years). Most patients with ATLL were from Peru (63%), Chile (17%), Argentina (8%), and Colombia (7%). Hypercalcemia was positively associated with acute type (57% v lymphomatous 27%, P = .014). The median survival times (months) were 4.3, 7.9, 21.1, and not reached for acute, lymphomatous, chronic, and smoldering forms, with 4-year survival rates of 8%, 22%, 40%, and 80%, respectively. First-line zidovudine (AZT)-interferon alfa (IFN) resulted in an overall response rate of 63% (complete response [CR] 24%) for acute. First-line chemotherapy yielded an overall response rate of 41% (CR 29%) for lymphomatous. CR rate was 42% for etoposide, cyclophosphamide, vincristine, doxorubicin, and prednisone versus 12% for cyclophosphamide, vincristine, doxorubicin, and prednisone–like regimen ( P < .001). Progression-free survival at 1 year for acute type patients treated with AZT-IFN was 67%, whereas 2-year progression-free survival in lymphomatous type patients who achieved CR after chemotherapy was 77%. CONCLUSION This study confirms Latin American ATLL presents at a younger age and has a high incidence of lymphomatous type, low incidence of indolent subtypes, and worse survival rates as compared with Japanese patients. In aggressive ATLL, chemotherapy remains the preferred choice for lymphomatous favoring etoposide-based regimen (etoposide, cyclophosphamide, vincristine, doxorubicin, and prednisone), whereas AZT-IFN remains a good first-line option for acute subtype.

Inadequate diagnostics compromise cancer care across lower- and middle-income countries (LMICs). We hypothesized that an inexpensive gene expression assay using paraffin-embedded biopsy specimens from LMICs could distinguish lymphoma subtypes without pathologist input. We reviewed all biopsy specimens obtained at the Instituto de Cancerología y Hospital Dr. Bernardo Del Valle in Guatemala City between 2006 and 2018 for suspicion of lymphoma. Diagnoses were established based on the World Health Organization classification and then binned into 9 categories: nonmalignant, aggressive B-cell, diffuse large B-cell, follicular, Hodgkin, mantle cell, marginal zone, natural killer/T-cell, or mature T-cell lymphoma. We established a chemical ligation probe-based assay (CLPA) that quantifies expression of 37 genes by capillary electrophoresis with reagent/consumable cost of approximately $10/sample. To assign bins based on gene expression, 13 models were evaluated as candidate base learners, and class probabilities from each model were then used as predictors in an extreme gradient boosting super learner. Cases with call probabilities &lt; 60% were classified as indeterminate. Four (2%) of 194 biopsy specimens in storage &lt;3 years experienced assay failure. Diagnostic samples were divided into 70% (n = 397) training and 30% (n = 163) validation cohorts. Overall accuracy for the validation cohort was 86% (95% confidence interval [CI]: 80%-91%). After excluding 28 (17%) indeterminate calls, accuracy increased to 94% (95% CI: 89%-97%). Concordance was 97% for a set of high-probability calls (n = 37) assayed by CLPA in both the United States and Guatemala. Accuracy for a cohort of relapsed/refractory biopsy specimens (n = 39) was 79% and 88%, respectively, after excluding indeterminate cases. Machine-learning analysis of gene expression accurately classifies paraffin-embedded lymphoma biopsy specimens and could transform diagnosis in LMICs.

The Epstein–Barr virus (EBV), Kaposi sarcoma herpesvirus (KSHV) and human T-lymphotropic virus (HTLV-1) are lymphomagenic viruses with region-specific induced morbidity. The RIAL-CYTED aims to increase the knowledge of lymphoma in Latin America (LA), and, as such, we systematically analyzed the literature to better understand our risk for virus-induced lymphoma. We observed that high endemicity regions for certain lymphomas, e.g., Mexico and Peru, have a high incidence of EBV-positive lymphomas of T/NK cell origin. Peru also carries the highest frequency of EBV-positive classical Hodgkin lymphoma (HL) and EBV-positive diffuse large B cell lymphoma, not otherwise specified (NOS), than any other LA country. Adult T cell lymphoma is endemic to the North of Brazil and Chile. While only few cases of KSHV-positive lymphomas were found, in spite of the close correlation of Kaposi sarcoma and the prevalence of pathogenic types of KSHV. Both EBV-associated HL and Burkitt lymphoma mainly affect young children, unlike in developed countries, in which adolescents and young adults are the most affected, correlating with an early EBV seroconversion for LA population despite of lack of infectious mononucleosis symptoms. High endemicity of KSHV and HTLV infection was observed among Amerindian populations, with differences between Amazonian and Andean populations.

No abstract

Extranodal natural killer/T-cell lymphoma (ENKTL) is an aggressive, rare lymphoma of natural killer (NK) cell origin with poor clinical outcomes. Here we used phenotypic and molecular profiling, including epigenetic analyses, to investigate how ENKTL ontogeny relates to normal NK-cell development. We demonstrate that neoplastic NK cells are stably, but reversibly, arrested at earlier stages of NK-cell maturation. Genes downregulated in the most epigenetic immature tumors were associated with polycomb silencing along with genomic gain and overexpression of EZH2. ENKTL cells exhibited genome-wide DNA hypermethylation. Tumor-specific DNA methylation gains were associated with polycomb-marked regions, involving extensive gene silencing and loss of transcription factor binding. To investigate therapeutic targeting, we treated novel patient-derived xenograft (PDX) models of ENKTL with the DNA hypomethylating agent, 5-azacytidine. Treatment led to reexpression of NK-cell developmental genes, phenotypic NK-cell differentiation, and prolongation of survival. These studies lay the foundation for epigenetic-directed therapy in ENKTL. Significance: Through epigenetic and transcriptomic analyses of ENKTL, a rare, aggressive malignancy, along with normal NK-cell developmental intermediates, we identified that extreme DNA hypermethylation targets genes required for NK-cell development. Disrupting this epigenetic blockade in novel PDX models led to ENKTL differentiation and improved survival. This article is highlighted in the In This Issue feature, p. 85

INTRODUCTION: Adult T-cell leukemia/lymphoma (ATLL) is a mature peripheral T-cell neoplasm caused by the Human T-cell Leukemia Virus Type 1 (HTLV-1). HTLV-1 infects up to 10 million people worldwide and is most endemic in Southwestern Japan, the Caribbean basin, South America, and Western Africa. In Latin America (LA), Peru and Brazil have the highest prevalence of HTLV-1-related diseases, however, data on ATLL in other LA countries is scarce. ATLL carries a dismal prognosis and is essentially incurable by conventional drugs. We describe the epidemiology, clinical features, treatment, and disease outcome of ATLL encountered in 11 countries in LA. METHODS: We retrospectively analyzed patients (pts) diagnosed with ATLL between January 1995 and December 2019. ATLL cases were classified according to the Shimoyama criteria into acute (A), lymphomatous (L), chronic (C) and smoldering (S). Treatment approaches used as first-line therapy were: 1) chemotherapy alone; 2) combined chemotherapy with zidovudine/interferon-alpha (AZT-IFN); and 3) AZT-IFN alone, as previously done with Miami cohort (Malpica and Ramos et al. Blood Advances 2018). Treatment response was assessed according to Tsukasaki et al. (JCO 2009) criteria. To be classified as complete response (CR), partial response and stable disease, these had to persist for a period of at least 4 weeks. Survival curves were estimated using the Kaplan-Meier method and Log rank test. RESULTS: A total of 253 pts with ATLL were identified. Two hundred twenty six pts (L=122, A=73, C=26, S=5) had sufficient data for analysis. Demographic and clinical features are shown in Figure 1 and Table 1. Median age at diagnosis was 57 years, with a female predominance in A (58%) and S (100%) types. Most ATLL pts were from Peru (n=159, 63%) followed by Chile (n=44, 17%), Argentina (n=20, 8%) and Colombia (n=17, 7%). B symptoms were high present in A, L and C types (73%, 72%, 58% vs. 8% S type, respectively, p=0.011). Hypercalcemia was highly associated with A type (57% vs. L 27%, p=0.014). The PIT score yielded to a more aggressive risk classification compared to the IPI score (high-risk: 55% vs. 29%, respectively, p&lt;0.001). Strongyloidiasis (n=5) and pneumocystis jirovecii pneumonia (n=5) were the most commonly observed co-infections at diagnosis. Commonly affected extranodal sites other than bone marrow in all subtypes were skin 25% (n=63) and liver 9% (n=24). The therapy approach used during the first 2 therapy evaluations are summarized in Table 2. The median survival (MS) times were 4.3 months, 7.9 months, 21.1 months, and not reached for A, L, C and S form, with 4-year survival of 8%, 22%, 40% and 80%, respectively (Figure 2). First-line AZT-IFN resulted in overall response (OR) rate of 63% (CR 24%) for A (n=8) and 75% (CR 50%) for L (n=8), respectively (Table 3). The OR rates after first-line multi-agent chemotherapy alone for A vs. L were 21% (CR 8%) and 41% (CR 29%), respectively (Table 3). The most commonly used regimens were CHOP/CHOP-like (n=117, 59%) and CHOEP (n=40, 20%) regimens with OR rates of 29% (CR 12%) and 60% (CR 42%), respectively (Table 3). Progression-free survival (PFS) rates in pts with aggressive ATLL who achieved CR after chemotherapy vs. AZT-IFN (alone or in combination with chemotherapy) were 2.8 months vs. 30.4 months for A (n=8) type and 67.1 months vs. 17.7 months for L (n=30) type, respectively (Figure 3). Only 2 pts with L type underwent allogeneic hematopoietic stem cell transplant (allo-HSCT) with PFS of 12 and 17 months (Table 4). CONCLUSION: ATLL continues to carry a dismal outcome with conventional therapies thus urging the development of novel approaches. Our study found that Latin American ATLL variant presents at a younger age, has a female predominance, high incidence of L type, low incidence of indolent types and lower survival rates, suggesting that Latin American ATLL variant presents earlier and more aggressively than in Japanese pts. AZT-IFN produced durable responses in A type patients who achieved CR as compared to chemotherapy alone. Chemotherapy responses were more durable in L types who achieved CR as compared to A type. In conclusion, in the management of aggressive ATLL, chemotherapy remains the preferred choice for L type (with consideration of allo-HSCT upfront), while AZT-IFN is a good option to attempt for A type upfront. Figure Disclosures Peña: Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sandoz: Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; Abbvie: Membership on an entity's Board of Directors or advisory committees; Amgen: Speakers Bureau; BindingSite: Research Funding. Idrobo:Amgen: Honoraria, Speakers Bureau; Janssen: Honoraria, Speakers Bureau; Tecnofarma: Honoraria, Speakers Bureau; Takeda: Honoraria, Speakers Bureau; Abbvie: Honoraria, Speakers Bureau. Altamirano:Hospital Nacional Guillermo Almenara Irigoyen: Other: Servicio de Hematologia. Perini:Abbvie: Speakers Bureau; Janssen: Honoraria, Speakers Bureau; Takeda: Honoraria. Castillo:Janssen: Consultancy, Research Funding; Abbvie: Research Funding; TG Therapeutics: Research Funding; Kymera: Consultancy; Pharmacyclics: Consultancy, Research Funding; Beigene: Consultancy, Research Funding. Ramos:NIH: Research Funding. Villela:Roche: Other: advisory board, Speakers Bureau; amgen: Speakers Bureau.

24 Background: NK/T-cell nasal type lymphoma is an aggressive non-Hodgkin lymphoma that destroys the palate and nasal anatomy. The incidence in the US and Europe is very low; however, Asia and South America have reported incidence up to 10-15%. This study was done to assess the incidence of this type of lymphoma in our institution, outcomes of treatment efficiency, and to explore demographic, clinical and biological characteristics associated with poor outcomes. Methods: Seventeen NK/T-cell lymphoma patients were diagnosed between 2014-2015, who were treated with radiotherapy plus weekly cisplatin 3-5 doses and consolidation with gemcytabine, oxaliplatin y L-asparaginase 1-4 doses or cisplatin, etopóside, ifosfamide and dexamethasone by 3 doses. Results: The incidence of NK/T-cell lymphoma was 9% of all lymphomas. Median age was 35 years (range: 20-64). The nose is the most frequent location (94.1%,16/17), and 23.5% (4/17) presented with high tumor burden. 100% of these patients presented with palate perforation. One patient presented with stage IV disease. All patients with high tumor burden and stage IV disease died with an overall survival (OS) of 5 months. Three of the deceased were Mayan people (75%). Guatemala's region with the highest incidence was Central (58%) and West (35.3%) vs. North, South and East (5.8%). 65% of the cases were Mayan people vs. 35% of mestizos. All patients had a poor or very poor socio-economic status. Twelve patients achieved complete response (70.6%). After a median follow-up time of 11 months, 1-year event-free survival and OS were 64.7%. Conclusions: The results of this study lead us to the conclusion that Guatemala's indigenous population in the west and center of the country are the most vulnerable population, which include mainly people with a poor socio-economic status. High tumor burden was associated with poor outcomes. Results achieved with radiotherapy plus cisplatin and consolidation with chemotherapy was effective. We recommend the development of educational programs to encourage early diagnosis of this lymphoma in areas of the population that are at risk. AUTHORS' DISCLOSURES OF POTENTIAL CONFLICTS OF INTEREST: Fabiola Valvert Travel, Accommodations, Expenses: Kedrion Biopharma, Asopharma Diana Flores No relationship to disclose

Introduction:The study of anti-SARS-CoV-2 IgG antibodies allows asymptomatic individuals with COVID-19 to be identified, and post-infection and post-vaccination immunity status to be evaluated. Objective: To know the behavior of anti-SARS-CoV-2 IgG antibodies before and after vaccination in workers of a cancer center. Methods: Prior to the application of the vaccine, the presence of anti-SARS-CoV-2 IgG antibodies (n = 171) was analyzed by evaluating anti-N IgG antibodies; post-vaccination, after receiving the second dose, anti-S IgG antibodies were evaluated (n = 60). Results: Prior to vaccination, IgG antibodies were present in 18.71% of participants; they were detected in 65.22% of those with prior history of COVID-19 diagnosis and in 11.49% of those without it. The positions with the highest prevalence were nurses (28.26%), paramedics (27.59%) and administrative workers (27.78%), p < 0.01. Anosmia, ageusia and chest tightness were associated with the presence of IgG (p < 0.05). Post-vaccination, all participants developed IgG antibodies; people with a previous COVID-19 diagnosis had higher titers: 10,277 vs. 6,819 AU/mL, p < 0.001. Conclusions: The study of anti-SARS-CoV-2 IgG antibodies allowed asymptomatic health workers to be identified. A high percentage of participants with prior COVID-19 diagnosis had antibodies. All participants developed IgG antibodies after vaccination, with higher titers being identified in those with previous infection.