Allogeneic haematopoietic stem cell transplantation as a salvage strategy for relapsed or refractory nasal NK/T-cell lymphoma

Resistance mechanisms and potential therapeutic strategies in relapsed or refractory natural killer/T cell lymphoma

ABSTRACT

Natural killer/T cell lymphoma (NKTCL) is a malignant tumor originating from NK or T cells, characterized by its highly aggressive and heterogeneous nature. NKTCL is predominantly associated with Epstein-Barr virus infection, disproportionately affecting Asian and Latin American populations. Owing to the application of asparaginase and immunotherapy, clinical outcomes have improved significantly. However, for patients in whom first-line treatment fails, the prognosis is exceedingly poor. Overexpression of multidrug resistance genes, abnormal signaling pathways, epigenetic modifications and active Epstein-Barr virus infection may be responsible for resistance. This review summarized the mechanisms of resistance for NKTCL and proposed potential therapeutic approaches.

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.

Allogeneic Stem Cell Transplantation for Patients with Natural Killer/T Cell Lymphoid Malignancy: A Multicenter Analysis Comparing Upfront and Salvage Transplantation

Natural killer (NK)/T cell lymphoid malignancy comprises extranodal NK/T cell lymphoma (ENKTL) and aggressive NK cell leukemia (ANKL), and the outcomes for advanced or relapsed/refractory ENKTL and ANKL remain poor. Allogeneic stem cell transplantation (SCT) can be used as a frontline consolidation treatment to prevent the relapse of advanced disease or as salvage treatment after chemotherapy for relapsed sensitive disease. We retrospectively analyzed 36 patients (ENKTL, n = 26; ANKL, n = 10) who underwent upfront (n = 19) and salvage allogeneic SCT (n = 17) at 6 hospitals. Patients received myeloablative (n = 25) or reduced-intensity (n =11) conditioning regimens depending on the institute's policy. The median age at the time of allogeneic SCT was 37 years (range, 17 to 62), and more patients with ANKL (8/10) received upfront allogeneic SCT than ENKTL patients (11/26). Disease status before allogeneic SCT, conditioning regimen, and donor source did not differ between upfront and salvage allogeneic SCT groups. Febrile neutropenia (n = 20) and acute graft-versus-host disease (n = 16) were common adverse events. The median overall survival (OS) and progression-free survival (PFS) after allogeneic SCT were 11.8 months and 10.0 months, respectively. Twelve patients died from disease relapse and 12 from nondisease-related causes. Ten deaths occurred within 100 days after allogeneic SCT (10/24); these were mostly related to disease relapse (n = 8). The OS after allogeneic SCT did not differ between ENKTL and ANKL (P = .550) or between upfront and salvage SCT (P = .862). Complete chimerism was significantly associated with better PFS (P < .001). No significant differences in PFS were observed based on the conditioning regimen or source of stem cells (P > .05). Allogeneic SCT may be beneficial for patients with ENKTL and ANKL given that some patients were able to maintain their remission after allogeneic SCT. However, allogeneic SCT should only be performed in highly selected patients because the risks of disease relapse and nondisease-related mortality remain high.

Clinical Practice Recommendations on Indication and Timing of Hematopoietic Cell Transplantation in Mature T Cell and NK/T Cell Lymphomas: An International Collaborative Effort on Behalf of the Guidelines Committee of the American Society for Blood and Marrow Transplantation

Recognizing the significant biological and clinical heterogeneity of mature T cell and natural killer (NK)/T cell lymphomas, the American Society for Blood and Marrow Transplantation invited experts to develop clinical practice recommendations related to the role of autologous hematopoietic cell transplantation (auto-HCT) and allogeneic HCT (allo-HCT) for specific histological subtypes. We used the GRADE methodology to aid in moving from evidence to decision making and ultimately to generating final recommendations. Auto-HCT in front-line consolidation is recommended in peripheral T cell lymphoma not otherwise specified (PTCL-NOS), angioimmunoblastic T cell lymphoma (AITL), anaplastic large cell lymphoma-anaplastic lymphoma kinase (ALCL-ALK)-negative, NK/T cell (disseminated), enteropathy-associated T cell lymphoma (EATL), and hepatosplenic lymphomas. Auto-HCT in relapsed-sensitive disease is recommended for NK/T cell (localized and disseminated), EATL, subcutaneous panniculitis-like T cell, and ALCL-ALK-positive lymphomas. Auto-HCT is also recommended for PTCL-NOS, AITL, and ALCL-ALK-negative lymphomas if not performed as front-line therapy. Auto-HCT in refractory (primary or relapsed) disease is not recommended for any of the histological subtypes discussed. Allo-HCT in front-line consolidation is recommended for NK/T cell (disseminated), adult T cell leukemia/lymphoma (ATLL; acute and lymphoma type), and hepatosplenic lymphomas. Allo-HCT for relapsed-sensitive disease is recommended for PTCL-NOS, AITL, ALCL-ALK-negative, ALCL-ALK-positive, NK/T cell (localized and disseminated), ATLL (acute, lymphoma type, smoldering/chronic), mycosis fungoides/Sezary syndrome (advanced stage IIB-IVB or tumor stage/extracutaneous), EATL, subcutaneous panniculitis-like T cell, and hepatosplenic lymphoma. Allo-HCT in refractory (primary or relapsed refractory) disease is recommended for any aforementioned histological subtypes. Emerging novel therapies will likely be incorporated into the pretransplantation, peritransplantation, and post-transplantation algorithms (auto-HCT or allo-HCT) with the goals of optimizing efficacy and improving outcomes. We acknowledge that there are unique clinical scenarios not covered by these recommendations that may require individualized decisions.

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.

Uveitis and Myositis as Immune Complications in Chemorefractory NK/T-Cell Nasal-Type Lymphoma Successfully Treated with Allogeneic Stem-Cell Transplant

NK/T-cell lymphomas are a group of clonal proliferations of NK- or, rarely, T-cell types and have peculiar clinicopathologic features. Most common site of involvement is the upper aerodigestive tract (nasal cavity, nasopharynx, paranasal sinuses, and palate). Association of autoimmune paraneoplastic disorders with NK/T-cell lymphomas is not well studied. Our patient was diagnosed with NK/T-cell lymphoma stage IV with skin involvement and treated frontline with CHOEP regimen. While he was under treatment, two immune complications presented: anterior uveitis of autoimmune origin refractory to steroids and myositis in lower limbs muscles. Autologous transplantation was rejected due to confirmed early relapse after first-line treatment, and the patient received second-line treatment according to the SMILE scheme, reaching complete response after four cycles. The patient underwent allogeneic transplantation and at the time of manuscript preparation is alive despite multiple complications. The disease should be suspected in patients with rhinitis or recurrent sinusitis, and early biopsy is recommended for all patients to avoid a delay in diagnosis. Our patient also presented symptoms of disease progression after first-line treatment, representing a paraneoplastic process, a very rare phenomenon in T-type lymphomas. This case is novel for the appearance of an inflammatory myositis, a histologically verified paraneoplastic phenomenon that responded to treatment for lymphoma.

Stem Cell Transplantation for Hematological Malignancies: Prospects for Personalized Medicine and Co-therapy with Mesenchymal Stem Cells

Bone marrow transplantation is a form of cell therapy that has been in practice for decades for the treatment of hematological disorders and solid tumors. Immunosuppressive therapy has been a mainstay for treatment, but the severity of the adverse effects has made it an undesirable choice. Mesenchymal stem cells (MSCs), which reside in the vascular regions of the bone marrow, have been shown to serve as cellular support for the hematopoietic stem cell (HSC) niche. Furthermore, the immune suppressive properties of MSCs have been explored in the treatment of inflammatory and autoimmune disorders. Thus, co-therapy with MSCs has been shown to facilitate engraftment of hematopoietic cells by suppressive graft versus host disease (GvHD). Although the mechanism by which MSCs suppress GvHD is unclear, the experimental evidence suggests that this partly occurs by modulation of immune response such as the induction of regulatory T cells. This paper discusses the role of MSCs as co-therapy for the future of stem cell transplantation, with the overarching theme of personalized medicine for cell-based health interventions.