Hematopoietic stem cell transplantation for natural killer-cell lineage neoplasms

Abstract

Neoplasms of natural killer (NK)-lineage are rare. Their prognosis is generally poor except for cases of solitary nasal NK-cell lymphoma. The NK-cell Tumor Study Group performed a survey in Japan on patients diagnosed between 1994 and 1998. Of 228 patients selected for analysis, 40 underwent HSCT (15 allografts and 25 autografts). The underlying diseases were myeloid/NK cell precursor acute leukemia (n = 4), blastic NK-cell lymphoma (n = 11), aggressive NK-cell leukemia (n = 3), and nasal-type extranodal NK-cell lymphoma (n = 22). At the time of HSCT, 22 patients were in complete remission (CR), 11 were in relapse, and seven were primary refractory. All patients received myeloablative conditioning regimens including total-body irradiation. Sixteen died of disease progression, and six of treatment-related causes. Overall, 4-year survival was 39% with a median follow-up of 50 months; this was significantly better than that of patients who did not undergo HSCT (21%, P = 0.0003). For patients transplanted in CR, the 4-year overall survival was 68%, which was significantly better than that of patients who went into CR but did not undergo HSCT (P = 0.03). These findings suggest that the HSCT is a promising treatment strategy for NK-cell lineage.

High-dose chemotherapy with autologous stem cell transplantation in extranodal NK/T-cell lymphoma: a retrospective comparison with non-transplantation cases

“…In retrospective analysis, they demonstrated a prolonged survival in patients who received HSCT as compared to those who did not undergo HSCT with statistical significance. 23 We have conducted a retrospective analysis in a series of NK/T-cell lymphomas to demonstrate the treatment outcome following HDC/ASCT. Although the role of HDC/ ASCT cannot be established through our study due to small sample size and limited statistical power, our study has demonstrated a tendency of favorable survival in NK/ T-cell lymphoma patients with CR at the time of transplantation, advanced disease or high NKIPI scores.…”

Current and future management of NK/T-cell lymphoma based on clinical trials

“…Several retrospective analyses have shown that some patients who underwent HSCT obtained a long-term CR [58,59], suggesting HSCT may be a cure-oriented therapy for disseminated ENKL, although these data were obtained before 'the SMILE era'. Recently, there have been accumulating data on the promising efficacy of allogeneic HSCT for relapsed or refractory ENKL [60,61], and experts in East Asia recommend allogeneic HSCT for this population [49,62].…”

Regression of the tumor after withdrawal of cyclosporine in relapsed extranodal natural killer/T cell lymphoma following allogeneic hematopoietic stem cell transplantation

“…Even with high-dose chemotherapy followed by autologous hematopoietic stem cell transplantation (HSCT), long-term survival has been observed only in patients who underwent HSCT at complete response (CR). In patients who are refractory to conventional chemotherapies, prognosis is almost always dismal even after autologous HSCT [6][7][8]. On the other hand, several anecdotal reports showed long-term disease free survival following allogeneic HSCT for advanced-stage ENKL, some of which had been refractory to conventional therapies before allogeneic HSCT [8][9][10].…”