Role of hematopoietic stem cell transplantation for relapsed acute promyelocytic leukemia: a retrospective analysis of JALSG-APL97.

For patients with relapsed acute promyelocytic leukemia (APL), all-trans retinoic acid-based salvage regimens can achieve second complete remission (CR2), but the optimal post-remission strategy for APL patients after CR2 remains unclear. Hematopoietic stem cell transplantation (HSCT) during CR2 might be effective, but data on the role of HSCT for APL patients after CR2 are limited in Japan. We retrospectively analyzed outcomes for 57 relapsed APL patients who achieved CR2 in the JALSG APL97 study. Of those, six received autologous (auto)-HSCT, 21 received allogeneic (allo)-HSCT, and 30 received various regimens other than HSCT. The 5-year event-free survival (EFS) rate, overall survival (OS) rate and cumulative incidence of relapse (CIR) were 50.7%, 77.4% and 51.0% in the non-HSCT group, 41.7%, 83.3% and 58.3% in the auto-HSCT group and 71.1%, 76.2% and 9.8% in the allo-HSCT group, respectively. Both the EFS rate and CIR were significantly better in the allo-HSCT group than in other groups. Allo-HSCT appears effective in APL patients in CR2, with a low relapse rate beyond a relatively early transplantation-related mortality (19%). Among older patients (age ≥40 years), the 5-year OS was significantly better in the non-HSCT group than in the HSCT group (78.0% vs 40.5%; P = 0.04). Further prospective studies with larger patient numbers are required to confirm the impact of HSCT alone and in combination with arsenic trioxide on outcomes for patients with APL in CR2.

Prospective measurement of Epstein-Barr virus-DNA in plasma and peripheral blood mononuclear cells of extranodal NK/T-cell lymphoma, nasal type.

Epstein-Barr virus (EBV)-DNA was prospectively analyzed in plasma and mononuclear cells (MNCs) from peripheral blood in patients with extranodal natural killer (NK)/T-cell lymphoma, nasal type, to evaluate the clinical significance for diagnosis, monitoring the tumor burden, and prognostication. Thirty-three patients were enrolled, and 32 were evaluable. Pretreatment plasma and MNC EBV-DNA was detectable in 14 (range, 50-71 000 copies/mL) and 6 patients (range, 20-780 copies/µg DNA), respectively, and both were well correlated (r = 0.8741, P < .0001). Detectable plasma EBV-DNA was associated with higher clinical stage (P = .02), presence of B symptoms (P = .02), worse performance status (P = .02), and higher serum soluble IL-2 receptor level (P < .0001). Twenty-two patients attained complete response. Plasma EBV-DNA level was significantly higher in nonresponders than in responders (mean, 16,472 vs 2,645 copies/mL; P = .02). Multivariate analysis showed clinical stage (hazard ratio, 9.0; 95% confidence interval, 1.8%-45.0%) and pretreatment plasma EBV-DNA (hazard ratio, 10.6; 95% confidence interval, 1.3%-87.0%) were significant prognostic factors. Three-year overall survival of plasma EBV-DNA positive and negative patients was 42.9% and 94.4%, respectively (P = .0009). Plasma was a preferable sample for this purpose in NK/T-cell lymphoma, nasal type, and EBV-DNA level was a good indicator for response and overall survival.

The therapeutic effect of rituximab on CD5-positive and CD5-negative diffuse large B-cell lymphoma.

The prognosis of diffuse large B-cell lymphoma (DLBCL) has improved markedly in recent years of rituximab era. The prognosis of de novo CD5-positive DLBCL is reported to be poor, but the effect of rituximab on this type of lymphoma remains unclear. To investigate the effect of rituximab on CD5-positive DLBCL, we collected DLBCL patients and analysed prognostic factors. A total of 157 patients with DLBCL who were immunophenotyped with flow-cytometry (FCM) and treated with chemotherapy were subjected to analysis. Those treated with radiotherapy alone or with supportive therapy only were not included. Patients diagnosed in 2003 or later were treated with rituximab combined chemotherapy. There were 95 males and 62 females. Their age ranged from 20 to 91 years old, and the median was 65 years. Nineteen patients were diagnosed as having de novo CD5-positive DLBCL. Rituximab was given alongside chemotherapy in 85 patients. Of these, 11 were positive for CD5 and 74 were negative. The addition of rituximab improved the overall survival (OS) of DLBCL patients (2-year OS: 82% vs. 70%, p = 0.01). For CD5-negative DLBCL, patients treated with rituximab showed 2-year OS of 84%, which was significantly better than those treated without rituximab (70%, p = 0.008). However, for CD5-positive DLBCL, the prognosis was not statistically different between the patients treated with and without rituximab (59% vs. 50%, p = 0.72). Although rituximab improved the prognosis of DLBCL, such improvement was restricted to the CD5-negative group. Further investigation is required to improve the prognosis of patients with CD5-positive DLBCL.

Central nervous system involvement in diffuse large B-cell lymphoma.

BACKGROUND: Malignant lymphoma with central nervous system (CNS) involvement has an extremely poor prognosis. We retrospectively studied the risk factors for CNS involvement in patients with diffuse large B-cell lymphoma (DLBCL) treated by cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) or rituximab (R) -CHOP chemotherapy. PATIENTS AND METHODS: We studied 375 consecutive patients who were newly diagnosed with DLBCL between 1996 and 2006. Patients with primary CNS involvement and patients who received CNS prophylaxis were excluded. All the patients received CHOP (n = 172) or R-CHOP (n = 203) chemotherapy. The following variables were assessed for their potential to predict CNS involvement: gender, age, serum lactate dehydrogenase (LDH) level, performance status, clinical stage, number of extranodal involvements, International Prognostic Index (IPI), bone marrow involvement, presence of a bulky mass, presence of B symptom, and treatment. RESULTS: CNS involvement was observed in 13 cases (3.5%). In univariate analysis, LDH more than normal range, LDH more than twice as normal range, high IPI, bone marrow involvement, and systemic relapse were the predictors for CNS involvement. In multivariate analysis, no risk factors were detected for CNS involvement. The use of rituximab did not have an impact on CNS involvement. CONCLUSIONS: The incidence of CNS involvement does not decrease in rituximab-era.

[ABVD chemotherapy for Hodgkin lymphoma at a single institute].

Fifty-eight newly diagnosed patients with Hodgkin lymphoma were treated with ABVD chemotherapy at Yokohama City University Hematology group from October 1996 to June 2005. The median age of patients age was 41 years old and ranged from 15 to 75. Thirty-eight patients were in the early stage and 20 patients were in the advanced stage. Patients in the early stage received 3 cycles of ABVD chemotherapy and involved-field radiation therapy, while those in the advanced stage received 6 cycles of ABVD chemotherapy. The overall response rate in patients was 100% (CR 87%, PR 13%) in the early stage and 95% in the advanced stage. With a median follow-up of 44 months, the 3-year progression-free survival and overall survival were 89% and 95% in the early stage, and 70% and 81% in the advanced stage, respectively. The results of this study were similar to those previously reported in Western countries.

Clinicopathological features of lymphoma/leukemia patients carrying both BCL2 and MYC translocations.

BACKGROUND: Lymphoid neoplasm with 18q21.3/BCL2 and 8q24/MYC translocation to immunoglobulin (IG) genes as dual-hit lymphoma/leukemia is very rare and known to have a poor clinical outcome. DESIGN AND METHODS: To clarify the clinicopathological characteristics of this malignancy, we analyzed 27 cases of cytogenetically proven dual-hit lymphoma/leukemia. RESULTS: Dual-hit lymphoma/leukemia was diagnosed at presentation in 22 cases and at relapse or disease progression in 5 cases. At the time of diagnosis of dual-hit lymphoma/leukemia, extranodal involvement was found in 25 cases (93%) and central nervous system involvement occurred in 15 cases (56%). The median survival and 1-year survival rate of the 27 cases were only 6 months and 22%, respectively, after diagnosis of the dual-hit lymphoma/leukemia. Seven cases of triple-hit lymphoma/leukemia (dual-hit lymphoma/leukemia with 3q27/BCL6 translocation) were included; the median survival of these patients was only 4 months from the diagnosis of the dual-hit lymphoma/leukemia. The duration of survival of the patients with a triple-hit malignancy was shorter than that of the other 20 cases of dual-hit lymphoma/leukemia (p=0.02). The translocation partner of MYC subdivided the dual-hit cases into two groups; 14 cases of IGH and 13 cases of IGK/L. The MIB-1 index was investigated in 14 cases with aggressive B-cell lymphoma, and was higher in the group with MYC-IGH translocation (n=7) than in the MYC-IGK/L group (n=7) (p=0.02). Overall survival was not different between the MYC-IGH translocation group (n=14) and the MYC-IGK or MYC-IGL translocation group (n=13). CONCLUSIONS: Dual-hit lymphoma/leukemia is a rare but distinct mature B-cell neoplasm with an extremely poor prognosis characterized by frequent extranodal involvement and central nervous system progression with either of the translocation partners of MYC.

Diffuse large B cell lymphoma without immunoglobulin light chain restriction by flow cytometry.

BACKGROUND: The existence of immunoglobulin light chain restriction (LCR) strongly indicates B cell monoclonality. Although LCR-deficient B cell malignancies are often observed, their details are barely known. METHODS: We retrospectively analyzed LCR-negative diffuse large B cell lymphoma (DLBCL) to elucidate their clinical features. Consecutive DLBCL patients (n = 119), whose histological diagnostic specimens were analyzed by flow cytometry (FCM), were divided into 2 groups: LCR-positive and LCR-negative DLBCL. Cases wherein FCM did not capture tumor cells were excluded. RESULTS: There were 91 LCR-positive (76%) and 28 LCR-negative (24%) DLBCL. The 2 groups did not differ with regard to background, including the International Prognostic Index (IPI), each factor of IPI, gender, bulky mass and B-symptoms. FCM analysis showed that CD10-positive cases were less frequent in the LCR-negative DLBCL group than in the LCR-positive DLBCL group. CD5-positive cases were absent in the LCR-negative DLBCL group. Chromosomal analysis showed that the frequency of BCL2, BCL6 and MYC translocations did not differ between the groups. There was no survival difference in the groups. CONCLUSION: LCR-negative DLBCL accounts for about one fourth of all DLBCL and their prognosis is similar to that of LCR-positive DLBCL. CD10-negative status might characterize LCR-negative DLBCL.

Features of primary extranodal lymphoma in Kanagawa, a human T-cell leukemia virus type 1 nonendemic area in Japan.

We sought to determine the frequency of primary extranodal lymphoma (ENL) and its characteristics in Kanagawa, a human T-cell leukemia virus type 1 (HTLV-1) nonendemic area in Japan. Subjects were 847 newly diagnosed patients with malignant lymphoma at the Yokohama City University Hospital and 8 affiliated hospitals mainly located in Kanagawa prefecture from 1999 to 2005. We compared the clinicopathological characteristics of primary ENL with primary nodal lymphoma (NL). Histological specimens were evaluated according to the World Health Organization classifications. A total of 395 (46.6%) and 452 (53.4%) patients had primary ENL and primary NL, respectively. The frequency of primary ENL increased with age. Primary extranodal sites included the gastrointestinal tract (30.4%), Waldeyer's ring (17.8%), orbits (7.0%), soft tissue and subcutaneous tissue (5.2%), bone (4.6%), skin (4.3%), thyroid gland (4.3%), testis and prostate (3.3%), bone marrow (3.3%), nasal and paranasal cavities (2.6%), salivary glands (2.3%), lung and pleura (2.0%), breast (1.8%), central nervous system (1.0%), uterus and ovary (0.5%), and others (9.8%). Among the 395 cases of primary ENL, diffuse large B-cell lymphoma (61.2%) was most frequently diagnosed, followed by extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (13.3%) and follicular lymphoma (5.6%). The frequency of primary ENL is approximately 50% of the total lymphoma cases in Kanagawa, an HTLV-1 nonendemic area in Japan. This frequency appears to be higher than that in Western countries.

[Allogeneic hematopoietic stem cell transplantation from HLA one-locus-mismatched related donors].

Fourteen patients who received allogeneic hematopoietic stem cell transplantation (HSCT) from a serologically HLA one mismatched related donor (MMRD) between November 1987 and July 2003, were compared with HSCT from matched sibling donor (MSD) (n=142) or matched unrelated donor (MUD) (n=78). Cumulative incidence of acute graft-versus-host disease (GVHD) in patients with MMRD was significantly higher than in those with MSD, but was not different from that in those with MUD. There was no difference in the incidence of extensive type chronic GVHD in HSCT according to donor type. Overall survival (OS) at 5-years in patients with MMRD, MSD and MUD was 42.8%, 55.6% and 44.3%, respectively. The presence of acute GVHD and disease status at HSCT were identified as risk factors for overall survival by multivariate analysis. Acute GVHD was a risk factor for prognosis in patients with MSD and MUD, but not in those with MMRD. It was confirmed that the therapeutic results could be obtained in HSCT from MMRD as well as MUD.

[Discrepant results of ABO type of red cells and serum in a patient with acute myelogenous leukemia].

A 42-year-old woman was admitted to our hospital with acute myelogenous leukemia. We conducted blood-type examination, and her serum showed strong agglutination with all B cells but questionable agglutination with A1 cells, which became stronger with incubation. We considered her blood type as O, but her previously assessed blood type was A. After receiving one cycle of induction therapy, she achieved complete remission and blood group A antigen was proven on her red blood cells. Anti-A1 in her serum disappeared after induction therapy. We should be aware that blood group antigens are not entirely independent of the environment and are occasionally modified by disease.

Treatments and Outcomes of Patients With Extranodal Natural Killer/T-Cell Lymphoma Diagnosed Between 2000 and 2013: A Cooperative Study in Japan.

Purpose To elucidate the management and outcomes of patients with extranodal natural killer/T-cell lymphoma, nasal type (ENKL), who were diagnosed between 2000 and 2013 in Japan. Patients and Methods Data from 358 patients with ENKL diagnosed between 2000 and 2013 from 31 institutes were retrospectively analyzed. Results Patients' median age was 58 years, and 257 (72%) had localized disease. The most common first-line treatment was radiotherapy with dexamethasone, etoposide, ifosfamide, and carboplatin (RT-DeVIC) (66%) for localized ENKL and L-asparaginase-containing chemotherapy (30%) for advanced ENKL. With a median follow-up of 5.8 years, overall survival (OS) rates at 5 years for localized and advanced ENKL were 68% and 24%, respectively. The prognostic index of natural killer lymphoma was validated in our study, although only 4% of patients with localized ENKL were classified as high risk. With a median follow-up of 5.6 years, OS and progression-free survival at 5 years in the 150 patients who received RT-DeVIC in clinical practice were 72% (95% CI, 63% to 78%) and 61% (95% CI, 52% to 69%), respectively. Toxicities of RT-DeVIC were comparable to those in a previous trial. Multivariate analysis in patients with localized ENKL who received RT-DeVIC identified elevated soluble interleukin-2 receptor as an independent predictive factor for worse OS and progression-free survival (adjusted hazard ratios, 2.28 and 2.46; 95% CI, 1.24 to 4.23 and 1.42 to 4.28; P = .008 and .0014, respectively). Conclusion Favorable OS in response to new treatments was demonstrated in a large number of patients. Improved treatment approaches are needed for localized ENKL exhibiting elevated pretreatment soluble interleukin-2 receptor.

Four-color flow cytometric analysis of myeloma plasma cells.

We monitored the behavior of residual myeloma plasma cells in patients with multiple myeloma after high-dose therapy and autologous or allogeneic transplantation using 3 methods of a flow cytometric technique using 4-color staining, immunofixation, and polymerase chain reaction approaches. We analyzed 17 cases by a relatively simple flow cytometric technique using CD38/CD45/CD19/CD56. Detectable myeloma plasma cells were found in 5 patients at diagnosis and 9 patients after treatment. Of 14 cases, 9 (64%) had CD19-CD56+ myeloma plasma cells, and 5 (36%) of 14 had CD19-CD56- myeloma plasma cells. When 37 bone marrow samples that had less than 5% myeloma plasma cells were assessed, myeloma plasma cells were detected in all 20 immunofixation-positive cases and 3 of 17 immunofixation-negative cases (P = .002). All 4 polymerase chain reaction-negative samples characterized as immunofixation-negative contained no detectable myeloma plasma cells. Flow cytometry can provide effective information to detect low levels of myeloma plasma cells.

[Hematopoietic stem cell transplantation in the second or later complete remission in acute promyelocytic leukemia initially treated with all-trans retinoic acid].

Despite the use of all-trans retinoic acid (ATRA) as the first-line treatment for acute promyelocytic leukemia (APL), relapse occurs in about 20% of cases. Most relapsing APL patients can achieve second remission (CR2) following ATRA combined with chemotherapy or arsenic trioxide. Stem cell transplantation (SCT) has been widely adopted in CR2, but optimal SCT (auto- or allo-SCT) remains controversial. We analyzed the outcomes for 8 APL patients initially treated using ATRA, who relapsed, achieved CR2 and underwent auto-SCT (n = 4) or allo-SCT (n = 4). The mean age of patients who underwent allo-SCT was 39 years. Minimal residual disease (MRD) just prior to SCT was positive in 1 patient and negative in 3. Engraftment was achieved in all patients, but 2 patients died of transplantation-related complications within 6 months. Complete molecular remission has been maintained in the remaining 2 patients. The mean age of patients who underwent auto-SCT was 48 years. MRD just prior to SCT was negative in all 4 patients. Complete molecular remission has been maintained in all 4 patients (mean follow-up, 3 years 9 months). The results for auto-SCT are favorable in patients with MRD-negative APL.

Pulmonary embolism and thrombotic thrombocytopenic purpura in acute promyelocytic leukemia treated with all-trans retinoic acid.

We describe a patient with acute promyelocytic leukemia (APL) who developed pulmonary embolism (PE) and thrombotic thrombocytopenic purpura (TTP) during remission induction all-trans retinoic acid (ATRA) therapy. A 44-year-old man was diagnosed with APL and was treated with ATRA. On day 14, he developed PE, and on day 24, he developed TTP. Both PE and TTP occurred in association with leukocytosis due to ATRA administration. The PE responded to dexamethasone and TTP responded to plasma infusion. The PE and TTP remitted, and he achieved complete remission of APL. To our knowledge, there have been no reports of TTP occurring as a complication of ATRA therapy.

[Allogeneic peripheral blood stem cell transplantation for a hepatitis B virus carrier with Epstein-Barr virus associated with hemophagocytic syndrome].

We report herein a 21-year-old hepatitis B virus (HBV) female carrier who developed persistent fever, lymphadenopathy and pancytopenia in September of 2000. Hemophagocytes were found in the bone marrow smears. Epstein-Barr virus (EBV) serology showed positive for VCA-IgG, IgM and EB-ER and negative for EBNA. The EBV genome was detected in the peripheral blood. The patient was diagnosed as having EBV-associated hemophagocytic syndrome (EBV-AHS) and received chemotherapy. Although she was treated with lamivudine three months after the initiation of chemotherapy, she developed severe hepatitis. She recovered from the hepatitis through a combination of plasma exchange, immunosuppressive and antiviral therapies. Because of the refractoriness of her EBV-AHS to chemotherapy, she received allogeneic peripheral blood stem cell transplantation (PBSCT) from her HLA-identical brother. Hepatitis B did not recur after the PBSCT under administration of lamivudine. The EBV genome in the peripheral blood disappeared soon after the PBSCT but it was revealed again after the initiation of prednisolone for the treatment of acute GVHD. A donor lymphocyte infusion (DLI) was given on day 169 and the EBV genome copy number in the peripheral blood gradually decreased and disappeared. Although the origin of the EBV-infected cells could not be determined as being from the host or donor, DLI was a useful treatment for the recurrence of EBV infection after allogeneic stem cell transplantation for EBV-AHS.

Phase II study of CHOP-GR therapy in diffuse large B-cell lymphoma.

We investigated a fixed scheme of combination chemotherapy protocol including CHOP, granulocyte colony stimulating factor (G-CSF) and rituximab (CHOP-GR) for patients with diffuse large B cell lymphoma (DLBCL) in a phase II clinical trial. Forty-four patients were registered: 21 patients <61 years of age in the low or low-intermediate International Prognostic Index (IPI) risk group and 23 patients between 61 and 70 years of age in any IPI risk group. The patients underwent two courses of CHOP chemotherapy followed by four courses of CHOP-GR, including subcutaneous G-CSF on days 11-14 and rituximab on day 15. An additional two courses of weekly rituximab were administered. Of the assessable 43 patients, complete remission occurred in 39 (91 %), partial remission in one (2 %), and progressive disease in three (7 %). In the median 53-month observation period in alive patients, the 5-year overall survival rate of the 43 patients was 77 % and the 5-year progression-free survival rate was 69 % with a subsequent plateau. There were nine deaths in the 43 patients, all of which were attributable to lymphoma progression. The most frequent adverse events were leukocytopenia (98 %), neutropenia (94 %), lymphocytopenia (91 %), and alopecia (83 %). CHOP-GR is a safe and effective therapy for patients with untreated DLBCL.

Pretreatment EBV-DNA copy number is predictive of response and toxicities to SMILE chemotherapy for extranodal NK/T-cell lymphoma, nasal type.

PURPOSE: Extranodal NK/T-cell lymphoma, nasal type (ENKL) is an Epstein-Barr virus (EBV)-associated lymphoma for which a new chemotherapeutic regimen called SMILE (steroid, methotrexate, ifosfamide, L-asparaginase, and etoposide) recently showed promising results. EXPERIMENTAL DESIGN: The amount of EBV-DNA was prospectively measured in whole-blood and plasma samples by real-time quantitative PCR from 26 patients registered in the SMILE phase II study. RESULTS: Before treatment, the EBV-DNA was detected in 22 samples of whole blood with a median number of 3,691 copies/mL (range: 0-1.14 × 10(7)), but 15 samples of plasma with a median of 867 copies/mL (range: 0-1.27 × 10(7)). Results of these 2 measurements of EBV-DNA well correlated (R(2) = 0.994, P < 0.001). The overall response rate to SMILE was significantly higher in patients with less than 10(5) copies/mL of EBV-DNA in whole blood at enrollment (90% vs. 20%, P = 0.007) and in patients with less than 10(4) copies/mL of EBV-DNA in plasma (95% vs. 29%, P = 0.002). The incidence of grade 4 toxicity of SMILE other than leukopenia/neutropenia was significantly higher in patients with 10(5) copies/mL of EBV-DNA or more in whole blood (100% vs. 29%, P = 0.007) than that of others and in patients with 10(4) copies/mL or more in plasma (86% vs. 26%, P = 0.002). CONCLUSIONS: These findings suggest that whole blood is more sensitive for clinical use than plasma. The EBV-DNA amount in whole blood was useful for predicting tumor response, toxicity, and prognosis after SMILE chemotherapy for ENKL.

Pretransplant serum ferritin is associated with bloodstream infections within 100 days of allogeneic stem cell transplantation for myeloid malignancies.

We retrospectively studied the association between iron overload and bloodstream infections (BSI) in the 100-day period following allogeneic hematopoietic stem cell transplantation (allo-HSCT) for acute myeloid leukemia or myelodysplastic syndromes. Serum ferritin was measured before transplantation to evaluate iron overload. Of 114 adult patients who underwent transplantation between 2000 and 2008, 36 (32%) developed BSI. Of the 44 isolates, 63% were Gram-positive bacteria, 32% were Gram-negative bacteria, and 4% were fungi. The median time to the onset of the first BSI was day 28 (range day 0-95) after transplantation. Univariate analysis revealed a significantly higher incidence of BSI in the high (≥ 1,000 ng/ml, n = 57) than in the low (< 1,000 ng/ml, n = 57) ferritin group (42.1 versus 21.1%, respectively, P = 0.017). Peripheral blood stem cell transplantation (PBSCT) (n = 23) showed a greater protective effect against BSI compared with bone marrow (n = 71) and cord blood (n = 20) transplantation. Pretransplantation serum ferritin (HR = 2.844, 95% CI: 1.180-6.859, P = 0.020) and PBSCT (HR = 0.135, 95% CI: 0.025-0.717, P = 0.019) were significant factors on multivariate analysis. In conclusion, pretransplantation serum ferritin significantly predicts BSI within the 100-day period after allo-HSCT.

Phase II study of SMILE chemotherapy for newly diagnosed stage IV, relapsed, or refractory extranodal natural killer (NK)/T-cell lymphoma, nasal type: the NK-Cell Tumor Study Group study.

PURPOSE: To explore a more effective treatment for newly diagnosed stage IV, relapsed, or refractory extranodal natural killer/T-cell lymphoma, nasal type (ENKL), we conducted a phase II study of the steroid (dexamethasone), methotrexate, ifosfamide, L-asparaginase, and etoposide (SMILE) regimen. PATIENTS AND METHODS: Patients with newly diagnosed stage IV, relapsed, or refractory disease and a performance status of 0 to 2 were eligible. Two cycles of SMILE chemotherapy were administered as the protocol treatment. The primary end point was the overall response rate (ORR) after the protocol treatment. RESULTS: A total of 38 eligible patients were enrolled. The median age was 47 years (range, 16 to 67 years), and the male:female ratio was 21:17. The disease status was newly diagnosed stage IV in 20 patients, first relapse in 14 patients, and primary refractory in four patients. The eligibility was revised to include lymphocyte counts of 500/µL or more because the first two patients died from infections. No treatment-related deaths were observed after the revision. The ORR and complete response rate after two cycles of SMILE chemotherapy were 79% (90% CI, 65% to 89%) and 45%, respectively. In the 28 patients who completed the protocol treatment, 19 underwent hematopoietic stem-cell transplantation. The 1-year overall survival rate was 55% (95% CI, 38% to 69%). Grade 4 neutropenia was observed in 92% of the patients. The most common grade 3 or 4 nonhematologic complication was infection (61%). CONCLUSION: SMILE chemotherapy is an effective treatment for newly diagnosed stage IV, relapsed or refractory ENKL. Myelosuppression and infection during the treatment should be carefully managed.