Hematopoietic stem cell transplantation in natural killer cell lymphoma and leukemia

Allogeneic Hematopoietic Stem Cell Transplantation in Extranodal Natural Killer/T-cell Lymphoma

Objective

Extranodal NK/T-cell lymphoma (ENKL) is aggressive and resistant to chemotherapy and radiotherapy. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a potentially curative treatment for high-risk lymphomas owing to its associated graft-versus-lymphoma (GVL) effect. However, its application to ENKL is limited. We aim to summarize the characteristics of allo-HSCT for ENKL and, more importantly, evaluate whether allo-HSCT could offer any benefits for ENKL.

Materials and Methods

A systematic review and data analysis were performed to evaluate the performance of allo-HSCT in the treatment of ENKL using studies obtained from PubMed, Medline, and Embase from January 2000 to December 2019 in the English language.

Results

A total of 136 cases from 17 eligible publications were included in this study. It was found that after allo-HSCT, with an average follow-up time of 34 months (range: 1-121 months), 37.5% (52) of 136 patients had acute graft-versus-host disease (GVHD) and 31.6% (43) had chronic GVHD. Furthermore, 35.3% (48) of the patients were reported to have relapsed, but 2 of those relapsed only locally and achieved complete remission (CR) again with additional irradiation, chemotherapy, and donor lymphocyte infusions for one and rapid tapering and discontinuation of cyclosporine for the other, earning more than one year of extra survival. Finally, of the 136 patients, 51.5% (70) died because of primary disease progression (42.9%), infection (20.0%), GVHD (11.4%), organ failure (7.1%), hemorrhage (4.3%), and other causes (not specified/unknown) (14.3%).

Conclusion

Allo-HSCT may be a treatment option for advanced or relapsed/refractory ENKL, but its role still requires more rigorous future studies.

Identifying high-risk patients with natural killer/T-cell lymphoma undergoing autologous stem cell transplantation

At present, autologous stem cell transplantation (ASCT) is considered as an optional consolidation therapy for natural killer/T-cell lymphoma (NKTCL). However, the high-risk patients undergoing ASCT are not clear enough. In this study, 56 patients with advanced staged or relapsed/refractory (R/R) NKTCL undergoing ASCT were reviewed. All patients achieved clinical complete response (CR) before ASCT. The median follow-up time was 36 months (range, 3-192 months). The three-year overall survival (OS) and three-year progression-free survival (PFS) were 70.2% and 56.5%, respectively. The independent prognostic factors for OS included prior testis involvement and pre-ASCT EBV-DNA. Patients without prior testis involvement and negative pre-ASCT EBV-DNA (group A) had better three-year OS (86.3% vs. 47.6%, p < .001) than the rest patients (group B). In conclusion, our study suggests that testis involvement and elevated EBV-DNA might be strong adverse prognostic factors for NKTCL. Patients without the above risk factors are more likely to benefit from ASCT.

Activity of pembrolizumab in relapsed/refractory NK/T-cell lymphoma

Natural killer/T-cell lymphoma (NKTCL) is a rare subtype of non-Hodgkin lymphoma that is associated with a poor outcome. Currently, the treatment needs of NKTCL remain unmet, and efforts to further improve treatment are urgently needed. Herein, seven patients with NKTCL who failed to respond to various types of chemotherapies were treated with the anti-programmed death 1 (anti-PD-1) antibody pembrolizumab at 100 mg every 3 weeks. After a median of four cycles of treatment (range 2-18), four out of seven patients responded (two complete response, two partial response, overall response rate 57%). Expression of PD1-ligand available was 50, 20, 30, 70, and 30% of five patients respectively. It is negative in one patient and not tested in one patient. Adverse events, which mostly ranged from grade I to grade III, were tolerable and could be safely handled, although immune-related pneumonitis was notable. Overall, PD-1 blockade with pembrolizumab represents a favorable strategy for the treatment of refractory/relapsed NKTCL.

Treatment of relapsed extranodal natural killer/T-cell lymphoma with bortezomib plus fludarabine

Extranodal NK/T cell lymphoma (ENKL) is a rare entity, associated with an aggressive clinical behavior and poor prognosis. The optimal treatment strategies, particularly for relapsed patients, have not been clearly determined. A 40-year-old female ENKL patient with orbital involvement as the first presentation was initially suspected to have an orbital pseudotumor. When the patient developed disease progression following treatment with methylprednisolone, biopsy of the orbital mass was performed. Histopathological examination of the biopsy specimen was consistent with the diagnosis of ENKL (Ann Arbor stage IE). The patient was then treated with radiotherapy followed by chemotherapy with dexamethasone, methotrexate, ifosfamide, L-asparaginase and etoposide (SMILE regimen). Despite an initial good response, the patient developed disease relapse and progression (stage IIIE). Subsequently, treatment was switched to a novel regimen comprising bortezomib and fludarabine as salvage therapy for two courses. A positron emission tomography scan revealed disappearance of the orbital tumor. The patient then received autologous hematopoietic stem cell transplantation. At the last follow-up (March 2017), the patient remained disease-free.

Clinical Features, Pathogenesis, and Treatment of Large Granular Lymphocyte Leukemias

Large granular lymphocytes (LGLs) are large lymphocytes with azurophilic granules in their cytoplasm. LGLs are either natural killer (NK) cells or T lymphocytes. Expansions of the LGLs in the peripheral blood are seen in various conditions, including three clonal disorders: T-cell LGL (T-LGL) leukemia, chronic lymphoproliferative disorders of NK cells (CLPD-NK), and aggressive NK-cell leukemia (ANKL). However, the monoclonal and polyclonal expansion of LGLs has been associated with many other conditions. The present article describes these LGL disorders, with special emphasis on the clinical features, pathogenesis, and treatments of the three above-mentioned clonal disorders.

Long complete remission achieved with the combination therapy of Cisplatin and gemcitabine in a patient with aggressive natural killer cell leukemia

Aggressive natural killer cell leukemia (ANKL) is a rare and often lethal lymphoproliferative disorder. Patients may present with constitutional symptoms, jaundice, skin infiltration, lymphadenopathy, and hepatosplenomegaly. ANKL can progress quickly to multiorgan failure and survival is usually measured in weeks. Although a rapid and accurate diagnosis is critical, unfortunately there is no hallmark diagnostic marker of ANKL. We report a case of a 48-year-old male who was able to obtain a complete remission following cisplatin-based chemotherapy. We describe the details of the chemotherapy regimens used and a literature review of the treatment of ANKL.

How I treat NK/T-cell lymphomas

Natural killer (NK)/T-cell lymphomas and NK-cell leukemias are aggressive malignancies. Occurring worldwide, they show a predilection for Asian and South American populations. Neoplastic cells are surface CD3-, cytoplasmic CD3ε+, CD56+, cytotoxic-molecule positive, Epstein-Barr virus (EBV) positive, with germline T-cell receptor gene. Lymphomas occur commonly in the nasal and upper aerodigestive region. Occasional cases present in the skin, salivary gland, testis, and gastrointestinal tract. Rare cases are disseminated with lymphadenopathy, hepatosplenomegaly, and a leukemic phase. Positron emission tomography computed tomography is useful in staging, as lymphomas are 18-fluorodeoxyglucose avid. Quantification of circulating EBV DNA is an accurate biomarker of tumor load. Nasal NK/T-cell lymphomas present mostly with stage I/II disease. Concomitant/sequential chemotherapy and radiotherapy is standard treatment. Radiotherapy alone is inadequate because of high systemic failure rate. For stage III/IV nasal, nonnasal, and disseminated lymphomas, systemic chemotherapy is indicated. Regimens containing l-asparaginase and drugs unaffected by P-glycoprotein are most effective. Hematopoietic stem cell transplantation (HSCT) is not indicated for early-stage nasal lymphomas. HSCT for lymphomas not in remission has poor results. In advanced-stage nasal, nonnasal, disseminated, or relapsed lymphomas, HSCT may be considered when remission is achieved. Prognostic modeling and EBV DNA monitoring may be useful in risk stratification for HSCT.

Current status of allogeneic transplantation for aggressive non-Hodgkin lymphoma

PURPOSE OF REVIEW

To provide a succinct update on the role of allogeneic stem cell transplantation (allo-SCT) in the management of patients with aggressive lymphomas. To clarify the indications for allogeneic transplantation vis-à-vis autologous transplant and to discuss the rationale and potential benefits of reduced intensity conditioning (RIC), nonmyeloablative (NMA) transplant, T-cell depletion and variations in graft vs. host disease (GVHD) prophylaxis.

RECENT FINDINGS

Considerable effort has been spent in developing transplant regimens with reduced toxicity and reduced GVHD. The role of allogeneic transplantation has also been redefined in light of advances in lymphoma classification, diagnostic methods, particularly PET scan and advances in transplant technology. Haplo and umbilical cord blood SCT allow identification of a donor for nearly all patients.

SUMMARY

In diffuse large B-cell lymphoma, the outcome of allo-SCT depends on patient characteristics and chemosensitivity. It is useful after failure of auto-SCT and in partial responses to salvage therapy. Allo-SCT may be the treatment of choice for advanced T-cell and natural killer cell lymphoma and for adult T-cell leukemia-lymphoma. Prophylactic or preemptive donor lymphocyte infusion may be useful, but requires controlled studies. RIC and NMA conditioning have reduced early toxicity but are associated with increased risk for disease recurrence. Promising data have been reported from a novel conditioning regimen combining NMA with ibritumomab tiuxetan. T-cell depletion reduces chronic GVHD but has some increase in rate of recurrence. Rapamycin may be associated with reduction in risk for disease recurrence.