Acute promyelocytic leukaemia long-term survivors: higher fatigue and greater overall symptom burden.

OBJECTIVE: We aimed to investigate the association of fatigue with severity of other key cancer symptoms, as well as symptom interference with daily activities and outlook on life, in long-term survivors of acute promyelocytic leukaemia (APL). METHODS: The study sample consisted of APL survivors (n=244), with a median time from diagnosis of 14.3 years (IQR=11.1-16.9 years), previously enrolled in a long-term follow-up study. Symptom severity and symptom interference were assessed using the well-validated MD Anderson Symptom Inventory (MDASI). Fatigue was evaluated with the Functional Assessment of Chronic Illness Therapy-Fatigue questionnaire. RESULTS: Higher fatigue burden was associated with increased affective symptoms, memory problems, drowsiness, sleep disturbances, shortness of breath and pain. Higher levels of fatigue were also associated with higher scores across all interference items of the MDASI. Overall, symptoms interfered most with mood, but among APL survivors with high levels of fatigue, symptoms interfered most with enjoyment of life. Multivariable regression analysis confirmed the independent association between fatigue and all symptom severity items of the MDASI. CONCLUSIONS: The current findings show that long-term APL survivors who report higher fatigue also experience a greater overall symptom burden and a substantial impact on performance of daily activities. Further studies are needed to examine whether interventions aimed at reducing fatigue could also reduce overall symptom burden.

Updated risk-oriented strategy for acute lymphoblastic leukemia in adult patients 18-65 years: NILG ALL 10/07.

An updated strategy combining pediatric-based chemotherapy with risk-oriented allogeneic hematopoietic cell transplantation (HCT) was evaluated in Philadelphia chromosome-negative acute lymphoblastic leukemia (Ph- ALL) and compared with a published control series. Following induction-consolidation chemotherapy, responsive patients were assigned to receive maintenance chemotherapy or undergo early HCT according to the risk stratification criteria and minimal residual disease (MRD) status. Of the 203 study patients (median age 41 years, range 17-67), 140/161 with Ph- ALL achieved complete remission (86.9%; 91.6% ≤55 years, P = 0.0002), with complete MRD clearing in 68/109; 55 patients were assigned to maintenance chemotherapy, and 85 to HCT due to very high-risk characteristics (hyperleukocytosis, adverse genetics, early/mature T-precursor ALL, and MRD persistence). The 5-year relapse incidence was 36%, and the treatment-related mortality rate was 18%. Median overall and relapse-free survival were 7.4 and 6.2 years, with rates of 54 and 53% at 5 years, respectively, which were significantly better than those obtained with the historical protocol (P = 0.001 and P = 0.005, respectively), without significant differences between maintenance and HCT cohorts. In prognostic analysis, MRD negativity and age ≤55 years were the most favorable independent prognostic factors. A reduction in treatment toxicity and further improvements in the risk definitions and risk-oriented design are the focuses of this ongoing research.

Nelarabine as salvage therapy and bridge to allogeneic stem cell transplant in 118 adult patients with relapsed/refractory T-cell acute lymphoblastic leukemia/lymphoma. A CAMPUS ALL study.

The outcome of relapsed or refractory (R/R) T-cell acute lymphoblastic leukemia/lymphoma (T-ALL/T-LBL) in adults is poor, with less than 20% of patients surviving at 5 years. Nelarabine is the only drug specifically approved for R/R T-ALL/T-LBL, but the information to support its use is based on limited available data. The aim of this observational phase four study was to provide recent additional data on the efficacy and safety of nelarabine in adults with R/R T-ALL/T-LBL and to evaluate the feasibility and outcome of allogeneic hematopoietic stem cell transplant (SCT) after salvage with nelarabine therapy. The primary endpoints were overall response rate (ORR) and overall survival (OS). Additional endpoints were safety, SCT rate and post-SCT OS. Between May 2007 and November 2018, 118 patients received nelarabine salvage therapy at 27 Italian hematology sites. The median age was 37 years (range 18-74 years), 73% were male, 77 had a diagnosis of T-ALL and 41 of T-LBL, and 65/118 (55%) had received more than two lines of therapy. The median number of nelarabine cycles was two (range 1-4); 43/118 (36%) patients had complete remission (CR), 16 had partial remission (14%) and 59 (50%) were refractory, with an ORR of 50%. The probability of OS, from the first dose of nelarabine, was 37% at 1 year with a median survival of 8 months. The OS at 1 year was significantly better for the 47 patients (40%) who underwent SCT after nelarabine salvage therapy (58% vs 22%, log-rank P < .001). The probability of OS at 2 and 5 years from SCT was 46% and 38%, respectively. Seventy-five patients (64%) experienced one or more drug-related adverse events (AE). Grade III-IV neurologic toxicities were observed in 9/118 (8%) of cases and thrombocytopenia or/and neutropenia (grade III-IV) were reported in 41% and 43% of cases, respectively. In conclusion, this is one of the largest cohorts of adult patients with R/R T-ALL/T-LBL treated in real life with nelarabine. Taking into account the poor prognosis of this patient population, nelarabine represents an effective option with an ORR of 50% and a CR rate of 36%. In addition, 40% of cases following nelarabine salvage therapy could undergo SCT with an expected OS at 2 and 5 years of 46% and 38%, respectively. The safety profile of nelarabine was acceptable with only 8% of cases showing grade III-IV neurological AE.

Health-related quality of life, symptom burden, and comorbidity in long-term survivors of acute promyelocytic leukemia.

The objective of this study was to investigate health-related quality of life (HRQOL), symptom burden, and comorbidity profile in long-term acute promyelocytic leukemia (APL) survivors treated with standard chemotherapy. Overall, 307 long-term APL survivors were invited to participate. HRQOL was assessed with the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) and compared with that of age and sex-matched controls from the general population. Symptom burden was assessed with the MD Anderson Symptom Inventory (MDASI) questionnaire and comorbidity profile was also investigated. Median follow-up time since diagnosis was 14.3 years (interquartile range: 11.1-16.9 years). APL survivors had a statistically and clinically meaningful worse score for the role physical scale of the SF-36 (-9.5; 95% CI, -15.7 to -3.2, P = 0.003) than their peers in the general population. Fatigue was reported as moderate to severe by 29% of patients and 84.4% reported at least one comorbidity. Prevalence of comorbidity in APL survivors was higher than that reported by the general population. Also, marked variations were found in the HRQOL profile by number of comorbidities. Even many years after treatment ends, APL survivors treated with standard chemotherapy do not fully recover as they report HRQOL limitations and a substantial burden of symptoms.

Achieving Molecular Remission before Allogeneic Stem Cell Transplantation in Adult Patients with Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia: Impact on Relapse and Long-Term Outcome.

Allogeneic stem cell transplantation (alloHSCT) in first complete remission (CR1) remains the consolidation therapy of choice in Philadelphia-positive (Ph+) acute lymphoblastic leukemia (ALL). The prognostic value of measurable levels of minimal residual disease (MRD) at time of conditioning is a matter of debate. We analyzed the predictive relevance of MRD levels before transplantation on the clinical outcome of Ph+ ALL patients treated with chemotherapy and imatinib in 2 consecutive prospective clinical trials. MRD evaluation before transplantation was available for 65 of the 73 patients who underwent an alloHSCT in CR1. A complete or major molecular response at time of conditioning was achieved in 24 patients (37%), whereas 41 (63%) remained carriers of any other positive MRD level in the bone marrow. MRD negativity at time of conditioning was associated with a significant benefit in terms of risk of relapse at 5 years, with a relapse incidence of 8% compared with 39% for patients with MRD positivity (P = .007). However, thanks to the post-transplantation use of tyrosine kinase inhibitors (TKIs), disease-free survival was 58% versus 41% (P = .17) and overall survival was 58% versus 49% (P = .55) in MRD-negative compared with MRD-positive patients, respectively. The cumulative incidence of nonrelapse mortality was similar in the 2 groups. Achieving a complete molecular remission before transplantation reduces the risk of leukemia relapse even though TKIs may still rescue some patients relapsing after transplantation.

Randomized trial of radiation-free central nervous system prophylaxis comparing intrathecal triple therapy with liposomal cytarabine in acute lymphoblastic leukemia.

Developing optimal radiation-free central nervous system prophylaxis is a desirable goal in acute lymphoblastic leukemia, to avoid the long-term toxicity associated with cranial irradiation. In a randomized, phase II trial enrolling 145 adult patients, we compared intrathecal liposomal cytarabine (50 mg: 6/8 injections in B-/T-cell subsets, respectively) with intrathecal triple therapy (methotrexate/cytarabine/prednisone: 12 injections). Systemic therapy included methotrexate plus cytarabine or L-asparaginase courses, with methotrexate augmented to 2.5 and 5 g/m(2) in Philadelphia-negative B- and T-cell disease, respectively. The primary study objective was the comparative assessment of the risk/benefit ratio, combining the analysis of feasibility, toxicity and efficacy. In the liposomal cytarabine arm 17/71 patients (24%) developed grade 3-4 neurotoxicity compared to 2/74 (3%) in the triple therapy arm (P=0.0002), the median number of episodes of neurotoxicity of any grade was one per patient compared to zero, respectively (P=0.0001), and even though no permanent disabilities or deaths were registered, four patients (6%) discontinued intrathecal prophylaxis on account of these toxic side effects (P=0.06). Neurotoxicity worsened with liposomal cytarabine every 14 days (T-cell disease), and was improved by the adjunct of intrathecal dexamethasone. Two patients in the liposomal cytarabine arm suffered from a meningeal relapse (none with T-cell disease, only one after high-dose chemotherapy) compared to four in the triple therapy arm (1 with T-cell disease). While intrathecal liposomal cytarabine could contribute to improved, radiation-free central nervous system prophylaxis, the toxicity reported in this trial does not support its use at 50 mg and prompts the investigation of a lower dosage. (clinicaltrials.gov identifier: NCT-00795756).

High cure rates in Burkitt lymphoma and leukemia: a Northern Italy Leukemia Group study of the German short intensive rituximab-chemotherapy program.

We evaluate the long-term results of a prospective clinical study enrolling more than 100 adult patients with Burkitt lymphoma/leukemia. Depending on extent of disease, treatment consisted of six to eight rituximab infusions and four to six courses of intensive chemotherapy (attenuated in patients aged >55 years) with high-dose methotrexate, fractionated ifosfamide/cyclophosphamide, other drugs in rotation, and intrathecal chemoprophylaxis. One-hundred five patients were treated (median age 47 years, range 17-78 years); 48% had Burkitt leukemia, 25% were older than 60 years, 37% had an Eastern Cooperative Oncology Group performance score >1, and 14% were positive for human immunodeficiency virus. The complete response rate and 3-year overall and disease-free survival rates were 79%, 67% and 75%, respectively, ranging from 100% to 45% for survival (P=0.000) and from 100% to 60% for disease-free survival (P=0.01) in patients with low, intermediate and high adapted International Prognostic Index scores. In multivariate analysis, only age (≤ versus >60 years) and performance status (0-1 versus >1) retained prognostic significance, identifying three risk groups with overall and disease-free survival probabilities of 88% and 87.5%, 57% and 70.5%, 20% and 28.5% (P=0.0000 and P=0.0001), respectively. The relapse rate was only 7% in patients treated with an intercycle interval ≤ 25 days. This regimen achieved 100% curability in patients with low adapted International Prognostic Index scores (21% of total), and very close to 90% in patients aged ≤ 60 years with performance score 0-1 (48% of total). Rapid diagnosis of Burkitt lymphoma/leukemia with prompt referral of patients to prevent clinical deterioration, and careful supervision of treatment without chemotherapy delay can achieve outstanding therapeutic results. ClinicalTrials.gov ID, NCT01290120.

Cytarabine and clofarabine after high-dose cytarabine in relapsed or refractory AML patients.

Clofarabine has been shown to be effective in AML patients, either as single agent or, mainly, in association with intermediate dose cytarabine. Based on these reports, we conducted a preliminary study combining clofarabine and intermediate dose cytarabine in AML patients who relapsed or failed to respond to at least two induction therapies. We treated 47 patients affected by relapsed/refractory AML with a regimen including clofarabine at 22.5 mg/m(2) daily on days 1-5, followed after 3 hr by cytarabine at 1 g/m(2) daily on days 1-5. Ten patients received a further consolidation cycle with clofarabine at 22.5 mg/m(2) and cytarabine at 1 g/m(2) day 1-4. Among the 47 patients, 24/47 (51%) achieved a complete remission, 5/47 (10.5%) a partial response, 10/47 (21%) had a resistant disease, and 6/47 (13%) died of complications during the aplastic phase. The most frequent nonhematologic adverse events were vomiting, diarrhea, transient liver toxicity, febrile neutropenia, and infections microbiologically documented. Among the 24 patients who obtained a CR 13 underwent allogeneic bone marrow transplantation. In 14 patients, complete remission duration was shorter than 12 months, whereas 10 patients experienced longer complete remission duration. These very preliminary results suggest that clofarabine-cytarabine regimen is effective in this particularly poor prognosis category of patients, representing a potential "bridge" toward bone marrow transplant procedures. Safety data were consistent with previously reported salvage therapies. Further studies and a longer follow up are warranted.

Pain management in hematological patients with major organ dysfunctions and comorbid illnesses.

BACKGROUND: Organ dysfunctions and medical complications, such as renal failure, liver impairment, coagulation disorders, cardiovascular and respiratory illnesses, may hamper an adequate pain management in haematological patients. AIM: To summarize current knowledge on pain management in hematological patients presenting major organ dysfunctions and comorbidity. We also attempted to provide recommendations to optimize analgesia and to minimize side effects in the setting of medically compromised and frail haematological patients. METHODS: A systematic search of the literature, using relevant key words, was conducted in PubMed. RESULTS AND CONCLUSIONS: Pain in hematological patients is a common symptom and is often multi-factorial. Most pharmacotherapeutic measures, including causal therapies, analgesics and adjuvant agents routinely applied in pain management, may also be used in the setting of clinical frailty and medical comorbidities; however, comprehensive clinical and functional patient's evaluations and a careful consideration of expected benefits and potential adverse events are required.

Results of a lymphoblastic leukemia-like chemotherapy program with risk-adapted mediastinal irradiation and stem cell transplantation for adult patients with lymphoblastic lymphoma.

The therapeutic role of mediastinal radiotherapy and stem cell transplantation (SCT) in lymphoblastic lymphoma (LL) remains controversial. In a risk-oriented design, we adopted a flexible treatment program in which (1) patients with persistent mediastinal abnormality, evaluated by post-induction computed chest tomography, received mediastinal irradiation; and (2) those with persistence of minimal residual disease (MRD), evaluated by MRD analysis of the bone marrow, underwent SCT. Twenty-eight out of 30 patients (T-lineage, n = 24; B-lineage, n = 6) achieved a complete response. Of 21 patients with mediastinal mass, 13 (62%) achieved a complete response after chemotherapy alone, while 6 (28.5%) required additional irradiation. Eleven patients were evaluated for MRD: 6 were negative and 5 positive. On the basis of MRD findings and clinical risk characteristics, 14 patients underwent SCT, 13 received maintenance chemotherapy, and 1 had local radiotherapy. Five patients relapsed. Among the 14 non-irradiated patients with T-LL, the mediastinal recurrence rate was only 7%. After a median follow-up of 3.9 years, 21 patients who responded were alive without recurrence (75%). The projected 5-year survival, disease-free survival, and relapse rate were 72%, 77%, and 18%, respectively. This program induced high remission and survival rates, indicating the feasibility and the benefits potentially associated with a selective, response-oriented policy of mediastinal irradiation and a concurrent MRD-based strategy to assign adult LL patients to SCT.

CD20 expression has no prognostic role in Philadelphia-negative B-precursor acute lymphoblastic leukemia: new insights from the molecular study of minimal residual disease.

The prognostic significance of CD20 expression in acute lymphoblastic leukemia has been investigated in children and adults but is still a subject of debate. The aim of our study was to correlate CD20 expression with clinical-biological characteristics and outcome in 172 Philadelphia chromosome negative patients prospectively treated in a multicenter trial introducing the molecular evaluation of minimal residual disease for therapeutic purposes. We considered 20% as the threshold for CD20 positivity. Complete remission rate, minimal residual disease negativity rate at weeks 10, 16 and 22, and disease-free and overall survival were similar among CD20-positive and -negative patients, even considering minimal residual disease results and related therapeutic choices. Our study failed to demonstrate any prognostic significance for CD20 expression in Philadelphia chromosome negative acute lymphoblastic leukemia. This conclusion is supported for the first time by a comparable minimal residual disease response rate among CD20-positive and -negative and positive patients.

Management of hematological malignancies in patients affected by renal failure.

The management of hematological malignancies (HM) in renally impaired patients may be a difficult task. Indeed, the kidney represents a major elimination pathway for many chemotherapeutic agents and their metabolites, whose serum levels are not usually measured in daily clinical practice. In addition, many antineoplastic drugs have a narrow therapeutic index for which they require dose adjustment when administered to patients with renal failure. Only limited data regarding the use of chemotherapy in patients with renal impairment and in those on dialysis are available. Indeed, renal patients with HM are often excluded from most clinical trials. Thus far, in order to provide recommendations, we have reviewed the pertinent literature, gathering information from published guidelines regarding chemotherapy in patients with kidney dysfunction and from articles describing the use of individual agents in renal patients with HM.

Pain in malignant hematology.

Pain is frequently experienced by patients with hematological malignancies, although it often receives little attention. Different underlying causes and mechanisms may sustain several pain syndromes in hematological malignant patients. Pain may be due to disease itself, to disease-related complications, to iatrogenic causes or may be associated with unrelated medical conditions. The management of pain in this setting requires a multidisciplinary approach, integrating analgesics and causal interventions. An accurate diagnostic assessment and the identification of the underlying causes and pathogenetic mechanisms may dictate the treatment approach. For most pain patients, the WHO's three-step analgesic scale for cancer pain relief can provide adequate relief with oral options, although difficult-to-treat pain syndromes, requiring a more complex treatment approach, may also be observed.

Chemotherapy-phased imatinib pulses improve long-term outcome of adult patients with Philadelphia chromosome-positive acute lymphoblastic leukemia: Northern Italy Leukemia Group protocol 09/00.

PURPOSE: Short imatinib pulses were added to chemotherapy to improve the long-term survival of adult patients with Philadelphia chromosome (Ph) -positive acute lymphoblastic leukemia (ALL), to optimize complete remission (CR) and stem-cell transplantation (SCT) rates. PATIENTS AND METHODS: Of 94 total patients (age range, 19 to 66 years), 35 represented the control cohort (ie, imatinib-negative [IM-negative] group), and 59 received imatinib 600 mg/d orally for 7 consecutive days (ie, imatinib-positive [IM-positive] group), starting from day 15 of chemotherapy course 1 and from 3 days before chemotherapy during courses 2 to 8. Patients in CR were eligible for allogeneic SCT or, alternatively, for high-dose therapy with autologous SCT followed by long-term maintenance with intermittent imatinib. RESULTS: CR and SCT rates were greater in the IM-positive group (CR: 92% v 80.5%; P = .08; allogeneic SCT: 63% v 39%; P = .041). At a median observation time of 5 years (range, 0.6 to 9.2 years), 22 patients in the IM-positive group versus five patients in the IM-negative group were alive in first CR (P = .037). Patients in the IM-positive group had significantly greater overall and disease-free survival probabilities (overall: 0.38 v 0.23; P = .009; disease free: 0.39 v 0.25; P = .044) and a lower incidence of relapse (P = .005). SCT-related mortality was 28% (ie, 15 of 54 patients), and postgraft survival probability was 0.46 overall. CONCLUSION: This imatinib-based protocol improved long-term outcome of adult patients with Ph-positive ALL. With SCT, post-transplantation mortality and relapse remain the major hindrance to additional therapeutic improvement. Additional intensification of imatinib therapy should warrant a better molecular response and clinical outcome, both in patients selected for SCT and in those unable to undergo this procedure.

Pain management in multiple myeloma.

Pain is a prominent feature of multiple myeloma (MM) and may be caused by different underlying causes and mechanisms. Indeed, pain may be due to disease-related complications, iatrogenic causes or may be associated with other unrelated medical conditions. This symptom may be particularly devastating and can negatively affect the quality of life of the afflicted patients and their functional status. For most MM patients suffering from continuous nociceptive pain, the WHO's three-step analgesic ladder can provide adequate relief with oral options, although the high prevalence in MM patients of difficult-to-treat pains, such as pains due to skeletal mechanical instability or sustained by neuropathic mechanisms, makes the treatment approach a challenging concern. The management of pain in this setting requires a multidisciplinary approach integrating analgesics and causal interventions. This review focuses on the most common syndromes afflicting MM patients, attempting to provide an understanding of the underlying pain mechanisms and a discussion of the most commonly used treatment strategies.

Palifermin in the management of mucositis in hematological malignancies: current evidences and future perspectives.

BACKGROUND: In the management of hematological malignancies, chemotherapy-induced mucositis is an increasingly recognized problem, leading to potentially severe clinical complications, treatment delays, increased costs and impairment of patient's quality of life. Many forms of cytotoxic treatments given in this setting may induce several degrees of mucositis. In particular, conditioning therapy with hematopoietic stem cell transplantation (HSCT) induces a disruption of the mucosal barrier function throughout the entire gastrointestinal tract facilitating the spreading of bacteria and endotoxin with subsequent increased risk of septicemia and, in the allogeneic setting, a worsening of Graft Versus Host Disease (GVHD). OBJECTIVES: To review the role of palifermin and of other existing and potential treatments for chemotherapy-induced mucositis in the context of current knowledge of pathobiology in the setting of hematological malignancies. METHODS: We searched for palifermin and mucositis of any region of the gastrointestinal tract using Medline; the abstract books of the most important hematological and oncological meetings were also reviewed. RESULTS/CONCLUSIONS: The pathobiology of mucositis is complex, and agents that target mechanisms to prevent mucositis or accelerate healing are highly required. In this regard, palifermin (recombinant human keratinocyte growth factor) has been demonstrated to reduce the severity and the duration of oral mucositis and to significantly improve several treatment outcomes in patients submitted to autologous HSCT; data are insufficient to recommend its use in the non-autologous HSCT settings, although interesting properties of this agent deserves other investigations in order to explore other possible indications.

Hemorrhagic complications in patients with advanced hematological malignancies followed at home: an Italian experience.

Patients with advanced hematological malignancies may experience many troublesome hemorrhagic complications requiring hospitalisation during a palliative home care (HC) program. We report on the feasibility of the management of bleeding at home in patients with haematological malignancies admitted in a domiciliary HC program. The occurrence of a major hemorrhage episode (>1 WHO grade) was registered among 469 patients with hematological malignancies in the terminal phase of their disease followed at home. Number, sites, domiciliary treatment (local hemostatic measures, platelet units, hemostatic drugs, packed red blood cells) and outcome of hemorrhagic complications were evaluated. Out of 469 patients, 123 (26%) experienced a bleeding complication; the overall number of hemorrhagic episodes was 232 (49%) with a median number of 2 episodes per patient. Patients with a platelet count lower than 20 x 10(9)/L (P < 0.00005) or with a diagnosis of acute leukemia or in blast crisis of myeloprolypherative disorders (P < 0.00005) showed a significant higher incidence of hemorrhages than other patients. Resolution of bleeding at home was obtained in 206 (88%) of the 232 episodes; platelet units were transfused at home in 188 (81%) cases. Bleeding was the cause of hospitalisation in four cases. Death occurred in 447 of 469 patients: in 26 of them (6%), it was caused by bleeding complications (11 brain hemorrhage, 2 hematemesis, 3 hemoptysis and 10 melena). In this group of patients, bleeding was a relevant clinical problem However, by implementing a domiciliary palliative care program, home management of hemorrhages proved to be a safe and effective choice.

Improved risk classification for risk-specific therapy based on the molecular study of minimal residual disease (MRD) in adult acute lymphoblastic leukemia (ALL).

Clinical risk classification is inaccurate in predicting relapse in adult patients with acute lymphoblastic leukemia, sometimes resulting in patients receiving inappropriate chemotherapy or stem cell transplantation (SCT). We studied minimal residual disease (MRD) as a predictive factor for recurrence and as a decisional tool for postconsolidation maintenance (in MRD(neg)) or SCT (in MRD(pos)). MRD was tested at weeks 10, 16, and 22 using real-time quantitative polymerase chain reaction with 1 or more sensitive probes. Only patients with t(9;22) or t(4;11) were immediately eligible for allogeneic SCT. Of 280 registered patients (236 in remission), 34 underwent an early SCT, 60 suffered from relapse or severe toxicity, and 142 were evaluable for MRD at the end of consolidation. Of these, 58 were MRD(neg), 54 MRD(pos), and 30 were not assessable. Five-year overall survival/disease-free survival rates were 0.75/0.72 in the MRD(neg) group compared with 0.33/0.14 in MRD(pos) (P = .001), regardless of the clinical risk class. MRD was the most significant risk factor for relapse (hazard ratio, 5.22). MRD results at weeks 16 to 22 correlated strongly with the earlier time point (P = .001) using a level of 10(-4) or higher to define persistent disease. MRD analysis during early postremission therapy improves risk definitions and bolsters risk-oriented strategies. ClinicalTrials.gov identifier: NCT00358072.