Obesity does not preclude safe and effective myeloablative hematopoietic cell transplantation (HCT) for acute myelogenous leukemia (AML) in adults

Complex association of body mass index and outcomes in patients with relapsed and refractory multiple myeloma treated with CAR-T cell immunotherapy

BACKGROUND AIMS

Chimeric antigen receptor-T (CAR-T) cells have exhibited remarkable efficacy in treating refractory or relapsed multiple myeloma (R/R MM). Although obesity has a favorable value in enhancing the response to immunotherapy, less is known about its predictive value regarding the efficacy and prognosis of CAR-T cell immunotherapy.

METHODS

We conducted a retrospective study of 111 patients with R/R MM who underwent CAR-T cell treatment. Using the body mass index (BMI) classification, the patients were divided into a normal-weight group (73/111) and an overweight group (38/111). We investigated the effect of BMI on CAR-T cell therapy outcomes in patients with R/R MM.

RESULTS

The objective remission rates after CAR-T cell infusion were 94.7% and 89.0% in the overweight and normal-weight groups, respectively. The duration of response and overall survival were not significant difference between BMI groups. Compared to normal-weight patients, overweight patients had an improved median progression-free survival. There was no significant difference in cytokine release syndrome and immune effector cell-associated neurotoxicity syndrome between the subgroups. In terms of hematological toxicity, the erythrocyte, hemoglobin, platelet, leukocyte and neutrophil recovery was accelerated in the overweight group. Fewer patients in the overweight group displayed moderate percent CD4 and CD4/CD8 ratios compared to the normal-weight group. Furthermore, the percent CD4 ratios were positively correlated with the levels of cytokines [interleukin-2 (IL-2) (day 14), interferon gamma (IFN-γ) (day 7) and tumor necrosis factor alpha (TNF-α) (days 14 and 21)] after cells infusion. On the other hand, BMI was positively associated with the levels of IFN-γ (day 7) and TNF-α (days 14 and 21) after CAR-T cells infusion.

CONCLUSIONS

Overall, this study highlights the potential beneficial effect of a higher BMI on CAR-T cell therapy outcomes.

Association between class III obesity and overall survival in previously untreated younger patients with acute myeloid leukemia enrolled on SWOG S1203

There has been ongoing debate on the association between obesity and outcomes in acute myeloid leukemia (AML). Currently few studies have stratified outcomes by class I obesity, class II obesity, and class III obesity, and a more nuanced understanding is becoming increasingly important with the rising prevalence of obesity. We examined the association between body mass index (BMI) and outcomes in previously untreated AML in younger patients (age ≤60) enrolled in SWOG S1203 (n = 729). Class III obesity was associated with an increased rate of early death (p = 0.004) and worse overall survival (OS) in multivariate analysis (hazard ratio (HR) 2.48, 95% confidence interval (CI) 1.62-3.80 versus normal weight). Class III obesity was also associated with worse OS after allogeneic hematopoietic cell transplant (HR 2.37, 95% CI 1.24-4.54 versus normal weight). These findings highlight the unique risk of class III obesity in AML, and the importance of further investigation to better characterize this patient population.

Association between class III obesity and overall survival in previously untreated younger patients with acute myeloid leukemia enrolled on SWOG S1203

There has been ongoing debate on the association between obesity and outcomes in acute myeloid leukemia (AML). Currently there are few studies that have stratified outcomes by class I obesity, class II obesity, and class III obesity; and a more nuanced understanding is becoming increasingly important with the rising prevalence of obesity. We examined the association between body mass index (BMI) and outcomes in previously untreated AML in younger patients (age ≤60) enrolled in SWOG S1203 (n=729). Class III obesity was associated with an increased rate of early death (p=0.004) and worse overall survival (OS) in multivariate analysis (hazard ratio (HR) 2.48, 95% confidence interval (CI) 1.62-3.80 versus normal weight). Class III obesity was also associated with worse OS after allogeneic hematopoietic cell transplant (HR 2.37, 95% CI 1.24-4.54 versus normal weight). These findings highlight the unique risk of class III obesity in AML, and the importance of further investigation to better characterize this patient population.

The impact of pre-transplantation diabetes and obesity on acute graft-versus-host disease, relapse and death after allogeneic hematopoietic cell transplantation: a study from the EBMT Transplant Complications Working Party

Obesity and diabetes can modulate immune responses, which may impact allogeneic HCT outcomes and GvHD. From the EBMT registry, we included 36,539 adult patients who underwent allogeneic HCT for a hematological malignancy between 2016 and 2020. Of these, 5228 (14%) had obesity (BMI ≥ 30 kg/m2), 1415 (4%) had diabetes (requiring treatment with insulin or oral hypoglycemics), and 688 (2%) had obesity + diabetes pre-transplantation. Compared with patients without diabetes or obesity, the hazard ratio (HR) of grade II-IV acute GvHD was 1.00 (95% confidence interval [CI] 0.94-1.06, p = 0.89) for patients with obesity, 0.95 (CI 0.85-1.07, p = 0.43) for patients with diabetes, and 0.96 (CI 0.82-1.13, p = 0.63) for patients with obesity + diabetes. Non-relapse mortality was higher in patients with obesity (HR 1.08, CI 1.00-1.17, p = 0.047), diabetes (HR 1.40, CI 1.24-1.57, p < 0.001), and obesity + diabetes (HR 1.38, CI 1.16-1.64, p < 0.001). Overall survival after grade II-IV acute GvHD was lower in patients with diabetes (HR 1.46, CI 1.25-1.70, p < 0.001). Pre-transplantation diabetes and obesity did not influence the risk of developing acute GvHD, but pre-transplantation diabetes was associated with poorer survival after acute GvHD.

Pre-transplant phase angle as a potential marker for predicting the development of infection after allogeneic hematopoietic stem cell transplantation

BACKGROUND & AIMS

Nutritional assessment in allogeneic hematopoietic stem cell transplantation (allo-HSCT) is important and decreased skeletal muscle mass is a risk factor for the development of infection. Recently, it has become clear that qualitative rather than skeletal muscle mass loss is a marker that reflects post-transplant outcome, but its association with the development of infection remains unclear. Therefore, we assessed skeletal muscle status by body composition using bioelectrical impedance analysis (BIA) and investigated its association with the development of infection.

METHODS

A retrospective cohort study was conducted to assess the quantity as well as quality of skeletal muscle using the body composition of BIA assessment. The quantitative (appendicular skeletal muscle mass index; ASM) and qualitative (phase angle; PhA) indicators of skeletal muscle calculated from body composition analysis were used to determine factors influencing the development of infection after allo-HSCT.

RESULTS

In total, 80 adult patients, aged 20-70 years (median, 52) were included in this study. The ASM was mildly decreased after allo-HSCT and PhA was significantly decreased. Furthermore, low pre-transplant PhA was identified as an independent risk factor for the development of infection early after transplantation, with a cutoff value of 4.9°.

CONCLUSION

In particular, pre-transplant PhA may predict the development of infection early after allo-HSCT, and muscle indices that can be assessed with pre-transplant body composition are a useful evaluation method that can discriminate post-transplant outcomes.

The Promise of Precision Nutrition for Modulation of the Gut Microbiota as a Novel Therapeutic Approach to Acute Graft-versus-host Disease

Acute graft-versus-host disease (aGVHD) is a severe side effect of allogeneic hematopoietic stem cell transplantation (aHSCT) that has complex phenotypes and often unpredictable outcomes. The current management is not always able to prevent aGVHD. A neglected actor in the management of aGVHD is the gut microbiota. Gut microbiota dysbiosis after aHSCT is caused by many factors and may contribute to the development of aGVHD. Diet and nutritional status modify the gut microbiota and a wide range of products are now available to manipulate the gut microbiota (pro-, pre-, and postbiotics). New investigations are testing the effect of probiotics and nutritional supplements in both animal models and human studies, with encouraging results. In this review, we summarize the most recent literature about the probiotics and nutritional factors able to modulate the gut microbiota and we discuss the future perspective in developing new integrative therapeutic approaches to reducing the risk of graft-versus-host disease in patients undergoing aHSCT.

Relationship Between Pretransplantation Nutritional Status and Outcome in Adults with Acute Myelogenous Leukemia Undergoing Allogeneic Hematopoietic Cell Transplantation

Pretransplantation nutritional status may impact outcome after allogeneic hematopoietic cell transplantation (HCT). Various simple screening tools have been developed and used to identify patients at risk of malnutrition; however, how best to use these screening tools is unclear, and their accuracy for the prediction of adverse outcomes is unknown. To investigate how these different measures contribute to outcome prediction, we examined a large cohort of adults with acute myelogenous leukemia (AML) who underwent allogeneic HCT in first or second remission at our institution between April 2006 and May 2021. We assessed the prognostic role of the Nutrition Risk Index (NRI), which combines weight loss and serum albumin, in 970 adults with AML in first or second remission who had usual body weight information available at AML diagnosis or relapse and before HCT. A low NRI at the time of conditioning for HCT was associated with higher nonrelapse mortality (hazard ratio [HR], .97; 95% confidence interval [CI], .95 to .98; P < .001) and relapse risk (HR, .98; 95% CI, .96 to .99; P < .001) and decreased relapse-free survival (HR, .97; 95% CI, .96 to .98; P < .001) and overall survival (HR, .97; 95% CI, .96 to .98; P < .001), as was a low pre-HCT serum albumin level. After multivariable adjustment, NRI, but not weight loss alone, was associated with outcome. The predictive ability of NRI was overall relatively low and comparable to that of serum albumin, with a C-statistic not exceeding .59. Taken together, our data indicate that pre-HCT level of serum albumin, an acute-phase protein recognized to more accurately reflect the severity of the inflammatory response compared with poor nutritional status, but not weight loss, is independently associated with post-HCT outcome in patients with AML. © 2022 American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc.

Association between high preoperative body mass index and mortality after cancer surgery

Despite an association between obesity and increased mortality in the general population, obesity has been paradoxically reported with improved mortality of surgery and some types of cancer. However, this has not been fully investigated in patients undergoing cancer surgery. Using a cohort consisting of mostly Asian population, we enrolled 87,567 adult patients who underwent cancer surgery from March 2010 to December 2019. They were divided into three groups according to body mass index (BMI): 53,980 (61.6%) in the normal (18.5–25 kg/m2), 2,787 (3.2%) in the low BMI (<18.5 kg/m2), and 30,800 (35.2%) in the high BMI (≥25 kg/m2) groups. The high BMI group was further stratified into overweight (25–30 kg/m2) and obese (≥30 kg/m2) groups. The primary outcome was mortality during three years after surgery. Following adjustment by inverse probability weighting, mortality during three years after surgery was significantly lower in the high BMI group than the normal (4.8% vs. 7.0%; hazard ratio [HR], 0.69; confidence interval [CI], 0.64–0.77; p < 0.001) and low BMI (4.8% vs. 13.0%; HR: 0.38; CI: 0.35–0.42; p < 0.001) groups. The mortalities of the overweight and obese groups were lower than that of the normal group (7.0% vs. 5.0%; HR: 0.72; CI: 0.67–0.77; p < 0.001 and 7.0% vs. 3.3%; HR: 0.57; CI: 0.50–0.65; p < 0.001, respectively). This association was not observed in female patients and those undergoing surgery for breast and gynecological cancers. High BMI may be associated with decreased mortality after cancer surgery. Further investigations are needed for clinical application of our finding.

Nutritional support in allogeneic hematopoietic stem cell transplantation Asian perspective

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is an integral part of the treatment strategy for patients with malignant or non-malignant hematological diseases. Clinical outcomes of patients undergoing allo-HSCT have significantly improved in recent decades. However, transplant-related morbidity and mortality remain major issues for allo-HSCT recipients. With regard to nutrition, patients undergoing allo-HSCT are at high risk for malnutrition. It is expected that clinical practice concerning nutritional support in allo-HSCT has been improving in recent decades; however, no data directly support this expectation. One major issue in managing nutritional support during allo-HSCT is the lack of large-scale randomized prospective studies, which leads to a lack of well-established strategies. Accordingly, we need to gather data from studies in non-HSCT and allo-HSCT settings. In some Asia-Pacific countries, a physician's lack of knowledge of nutritional support may impede the application of nutritional support practices recommended by existing guidelines. Another barrier may be the lack of access to an adequately qualified or trained registered dietitian (RD) at allo-HSCT units. Adequate training in the nutritional management of allo-HSCT patients should be provided to all RDs working with HSCT. Herein, we summarize the information on nutritional support in allo-HSCT, focusing on an Asian perspective.

Does recipient body mass index inform donor selection for allogeneic haematopoietic cell transplantation?

It is not known whether obesity has a differential effect on allogeneic haematopoietic cell transplantation outcomes with alternative donor types. We report the results of a retrospective registry study examining the effect of obesity [body mass index (BMI) > 30] on outcomes with alternative donors (haploidentical related donor with two or more mismatches and receiving post-transplant cyclophosphamide [haplo] and cord blood (CBU)] versus matched unrelated donor (MUD). Adult patients receiving haematopoietic cell transplantation for haematologic malignancy (2013-2017) (N = 16 182) using MUD (n = 11 801), haplo (n = 2894) and CBU (n = 1487) were included. The primary outcome was non-relapse mortality (NRM). The analysis demonstrated a significant, non-linear interaction between pretransplant BMI and the three donor groups for NRM: NRM risk was significantly higher with CBU compared to haplo at BMI 25-30 [hazard ratio (HR) 1.66-1.71, p < 0.05] and MUD transplants at a BMI of 25-45 (HR, 1.61-3.47, p < 0.05). The results demonstrated that NRM and survival outcomes are worse in overweight and obese transplant recipients (BMI ≥ 25) with one alternative donor type over MUD, although obesity does not appear to confer a uniform differential mortality risk with one donor type over the other. BMI may serve as a criterion for selecting a donor among the three (MUD, haplo and CBU) options, if matched sibling donor is not available.

Correlation of nutrition-associated parameters with non-relapse mortality in allogeneic hematopoietic stem cell transplantation

Outcome of allogeneic stem cell transplantation (alloSCT) is hampered by substantial non-relapse mortality (NRM). Given its impact on organ function and immune response, the nutritional status has been suggested as relevant for NRM. We aimed to evaluate the association of NRM with nutritional status prior to alloSCT and in the post-SCT course. In a retrospective single-center study, we analyzed 128 alloSCTs. Besides standard characteristics, nutrition-associated parameters BMI, serum total protein, and serum albumin were recorded before conditioning and at various time points after alloSCT. Association with NRM was evaluated by univariate and multivariate survival analysis. The cohort comprised patients with a median BMI of 26 kg/m² (16.7–46.9 kg/m²), median serum total protein of 59 g/l (41–77 g/l), and serum albumin of 36 g/l (22–46 g/l) before SCT. NRM at d₊₁₀₀ was 14.8% and at 1 year 26.6%. Prior to SCT, only serum albumin deficiency was associated with increased NRM (p = .010) in multivariate analysis. After SCT (d₊₃₀ and d₊₁₀₀), all nutrition-associated parameters decreased (p < .002), but no association of deteriorating nutritional status with NRM was found. In multivariate analysis, serum albumin (p = .03) and severe albumin deficiency (p = .02) correlated with NRM at d₊₃₀ and d₊₁₀₀, while BMI and serum total protein did not. In our study, albumin deficiency, particularly prior to alloSCT, shows a strong correlation with NRM. This finding may add to monitoring, risk evaluation, and counseling of patients and serve as a rational for interventions to improve the nutritional status in patients undergoing SCT.

Superior survival with pediatric-style chemotherapy compared to myeloablative allogeneic hematopoietic cell transplantation in older adolescents and young adults with Ph-negative acute lymphoblastic leukemia in first complete remission: analysis from CALGB 10403 and the CIBMTR

Optimal post-remission therapy for adolescents and young adults (AYAs) with Ph-negative acute lymphoblastic leukemia (ALL) in first complete remission (CR1) is not established. We compared overall survival (OS), disease-free survival (DFS), relapse, and non-relapse mortality (NRM) for patients receiving post-remission therapy on CALGB 10403 to a cohort undergoing myeloablative (MA) allogeneic hematopoietic cell transplantation (HCT) in CR1. In univariate analysis, OS was superior with chemotherapy compared to MA allogeneic HCT (3-year OS 77% vs. 53%, P < 0.001). In multivariate analysis, allogeneic HCT showed inferior OS (HR 2.00, 95% CI 1.5–2.66, P < 0.001), inferior DFS (HR 1.62, 95% CI 1.25–2.12, P < 0.001), and increased NRM (HR 5.41, 95% CI 3.23–9.06, P < 0.001) compared to chemotherapy. A higher 5-year relapse incidence was seen with chemotherapy compared to allogeneic HCT (34% vs. 23%, P = 0.011). Obesity was independently associated with inferior OS (HR 2.17, 95% CI 1.63–2.89, P < 0.001), inferior DFS (HR 1.97, 95% CI 1.51–2.57, P < 0.001), increased relapse (1.84, 95% CI 1.31–2.59, P < 0.001), and increased NRM (HR 2.10, 95% CI 1.37–3.23, P < 0.001). For AYA ALL patients in CR1, post-remission therapy with pediatric-style chemotherapy is superior to MA allogeneic HCT for OS, DFS, and NRM.

Nutritional Status at Diagnosis and Pre-transplant Weight Loss Impact Outcomes of Acute Myeloid Leukemia Patients Following Allogeneic Stem Cell Transplantation

The nutritional status at diagnosis, as well as weight loss during chemotherapy, are important factors for morbidity and mortality in cancer patients. They might also influence outcomes in patients with acute myeloid leukemia (AML) receiving allogeneic hematopoietic stem cell transplantation (HSCT). We evaluated the body mass index (BMI) at diagnosis, prior to HSCT, and the BMI difference (ΔBMI = BMI_HSCT–BMI_diagnosis) in 662 AML patients undergoing allogeneic HSCT. Patients being obese at AML diagnosis had significantly higher nonrelapse mortality (NRM) and shorter overall survival (OS) after HSCT, but no distinct cumulative incidence of relapse than nonobese patients. Weight loss during chemotherapy (ΔBMI > –2) was a strong predictor for higher NRM and shorter OS in univariate and multivariate analyses. These results were observed across all European LeukemiaNet (ELN) 2017 risk groups but especially in patients with favorable or intermediate ELN2017 risk and patients transplanted in morphologic complete remission. Only in patients being obese at AML diagnosis, weight loss did not result in adverse outcomes. ΔBMI > –2 represents a strong, independent, and modifiable risk factor for AML patients treated with HSCT. Nutritional monitoring and supplementation during disease course might improve patients’ outcomes.

Immuno-Metabolism and Microenvironment in Cancer: Key Players for Immunotherapy

Immune checkpoint inhibitors (ICIs) have changed therapeutic algorithms in several malignancies, although intrinsic and secondary resistance is still an issue. In this context, the dysregulation of immuno-metabolism plays a leading role both in the tumor microenvironment (TME) and at the host level. In this review, we summarize the most important immune-metabolic factors and how they could be exploited therapeutically. At the cellular level, an increased concentration of extracellular adenosine as well as the depletion of tryptophan and uncontrolled activation of the PI3K/AKT pathway induces an immune-tolerant TME, reducing the response to ICIs. Moreover, aberrant angiogenesis induces a hypoxic environment by recruiting VEGF, T_reg cells and immune-suppressive tumor associated macrophages (TAMs). On the other hand, factors such as gender and body mass index seem to affect the response to ICIs, while the microbiome composition (and its alterations) modulates both the response and the development of immune-related adverse events. Exploiting these complex mechanisms is the next goal in immunotherapy. The most successful strategy to date has been the combination of antiangiogenic drugs and ICIs, which prolonged the survival of patients with non-small-cell lung cancer (NSCLC) and hepatocellular carcinoma (HCC), while results from tryptophan pathway inhibition studies are inconclusive. New exciting strategies include targeting the adenosine pathway, TAMs and the microbiota with fecal microbiome transplantation.

Body mass index does not impact hematopoietic progenitor cell mobilization for autologous hematopoietic cell transplantation

BACKGROUND

Obesity has implications for hematopoietic progenitor cell (HPC) mobilization, chemotherapy administration, and medication dosing. We analyzed the impact of obesity on HPC mobilization as well as key outcomes that are associated with cell dose in autologous hematopoietic cell transplantation (AHCT) recipients.

METHODS

We conducted a retrospective cohort study on 556 consecutive eligible AHCT recipients at our institution from 1/2004 to 12/2009. Patients were categorized into four groups based on the body mass index (BMI): underweight (BMI < 18.5), normal (18.5-24.9), overweight (25.0-29.9), or obese (≥30.0). Primary endpoints of interest included HPC mobilization, neutrophil and platelet recovery, hospital stay and survival.

RESULTS

The diagnoses were mostly non-Hodgkin lymphoma, multiple myeloma, and Hodgkin lymphoma. The majority of the patients had received three or less prior chemotherapy regimens and had not received prior radiation therapy. Most patients had chemosensitive disease at time of transplant. For HPC mobilization regimen, 68% received chemotherapy and G-CSF, 32% received G-CSF alone. Busuflan/etoposide/cyclophosphamide, melphalan, and busulfan/cyclophosphamide were used for conditioning. Obesity did not correlate with HPC mobilization and had no association with neutrophil or platelet recovery, or length of transplant hospitalization. On multivariable analysis, obese patients demonstrated better survival than those who were not obese.

CONCLUSION

Obese AHCT recipients had similar rates of HPC mobilization, neutrophil and platelet engraftment and length of transplant hospitalization, and experienced better survival compared with recipients with lower BMI. High BMI by itself should not be considered as a contraindication to AHCT.

Impact of treatment-related weight changes from diagnosis to hematopoietic stem-cell transplantation on clinical outcome of acute myeloid leukemia

We hypothesized that treatment-related weight loss is associated with worse outcomes following HSCT. Overall, 184 patients with AML who underwent induction therapy were classified according to d-BMI (BMI at transplant minus BMI at diagnosis) (kg/m²) as < -2, - 2 to + 2, and > + 2. At 1 year, OS was 67.9% (95% CI, 60.7-74.2), DFS was 64.1% (95% CI, 56.7-70.6), and GRFS was 40.2% (95% CI, 33.1-47.2). For d-BMI groups < - 2, - 2 to + 2, and > + 2, GRFS at 1 year was 16.1% (95% CI, 5.1-31.4), 45.4% (95% CI, 36.4-53.7), and 41.7% (95% CI, 22.2-60.1), respectively (P = 0.0067). Multivariate analysis showed that both worse OS (HR, 1.78; 95% CI, 1.02-3.14; P = 0.007) and GRFS (HR, 2.34; 95% CI, 1.26-4.35; P = 0.007) were associated with reduced BMI (d-BMI < - 2). Treatment-related weight reduction in AML was associated with poor outcome after HSCT.

Monocyte Subpopulation Recovery as Predictors of Hematopoietic Cell Transplantation Outcomes

Monocyte recovery after hematopoietic cell transplantation (HCT) has been correlated with overall survival (OS). However, monocytes are heterogeneous and consist of classic (CD14⁺⁺CD16^-), intermediate (CD14⁺CD16⁺), and nonclassic (CD14⁺CD16⁺⁺) subpopulations, with unique functional properties. We hypothesized that monocyte subpopulation reconstitution would vary based on allogeneic stem cell source and would be associated with outcomes. We studied monocyte subpopulation recovery at days 28, 60, 100, 180, and 365 post-HCT among 202 patients with hematologic malignancy. Significant differences in absolute monocyte count (AMC) and monocyte subpopulation counts at days 60 and 100 were identified based on stem cell source (all P < .01), with more robust recovery in umbilical cord blood (UCB) recipients. Using 2-fold cross-validation, optimal cutpoints were calculated for day 28 AMC and monocyte subpopulations based on OS. These were used to calculate hazard ratios for OS, disease-free survival (DFS), relapse, transplant-related mortality (TRM), and acute and chronic graft-versus-host disease. OS and DFS were superior when AMC and classic monocyte recovery were above optimal cutpoints (all P < .03). Relapse was reduced for those with AMC (P < .01) and classic (P = .05) monocyte counts above optimal cutpoints. TRM was also reduced when classic (P = .02) monocyte count exceeded optimal cutpoints. Intermediate and nonclassic monocyte recovery were not associated with outcomes. In summary, hematopoietic cell source is associated with monocyte subpopulation recovery, with the early robust recovery in UCB recipients. Recovery of AMC and classic monocytes were prognostic for survival, relapse, and TRM. These indicators may identify patients at increased risk for post-HCT failure and guide therapeutic interventions.

Sarcopenic obesity derived from PET/CT predicts mortality in lymphoma patients undergoing hematopoietic stem cell transplantation

BACKGROUND

Sarcopenic Obesity (SO) is associated with worse survival among chemotherapy recipients. Research on SO is scarce among lymphoma patients receiving Hematopoietic Stem Cell Transplantation (HSCT).

AIM

assess prevalence of SO pre-HSCT (T0) and 3 months post-HSCT (T1) in lymphoma patients and determine the power of SO at T0 and T1 in predicting survival.

METHODS

Consecutive patients (age ≥16 years) having B and T cell lymphoma who underwent SCT and who had PET/CT scan pre-SCT and 3 months post SCT were included in the study. A cross sectional image was analyzed at the level of the 3rd Lumber Vertebrae to assess body composition parameters.

RESULTS

93 patients [mean age: 38 (range: 17-70 years), 52 (55.9%) males, 45 (48%) Hodgkin and 48 (52%) Non-Hodgkin lymphoma, 81 (87%) autologous and 12 (13%) allogeneic SCT)] met the inclusion criteria. From T0 to T1, Sarcopenia rates increased (27% at T0 to 38% at T1, p = 0.013), Visceral adiposity decreased (46% at T0 to 30% at T1, p = 0.03) and SO decreased (42% at T0 to 20% at T1, p < 0.01). Length of stay, overall survival and progression free survival were significantly better in patients without sarcopenic obesity at T1. Cox-regression revealed SO at T1 was a risk factor for mortality [Adjusted Hazards Ratio = 8.2 (95% Confidence Interval: 1.9-36.2)].

CONCLUSION

Sarcopenic obesity, prevalent in 42% of patients pre-HSCT, decreased 3 months post HSCT as lymphoma patients lost skeletal muscle and visceral adipose tissues. SO at T1 was the most impactful risk factor for mortality.

Impact of Body Mass Index on Outcomes of Hematopoietic Stem Cell Transplantation in Adults

This retrospective analysis of 2503 adult (age ≥20 years) allogeneic hematopoietic cell transplantation (HCT) recipients assessed the effect of body mass index (BMI) on transplantation outcomes. The median patient age was 51.7years. Patients with both nonmalignant and malignant diagnoses were included. Patients received either a myeloablative (52%) or a reduced-intensity (48%) conditioning regimen. Donors were either related (42%) or unrelated (58%). Cord blood recipients were excluded. Granulocyte colony-stimulating factor-mobilized peripheral blood cells were the stem cell source in 86% of transplantations. Graft-versus-host disease prophylaxis included at least 2 immunosuppressive agents, 1 of which was a calcineurin inhibitor. Patient groups were categorized as underweight, normal weight, overweight, obese, or very obese based on BMI. Endpoints included day +100 mortality, overall mortality, nonrelapse mortality (NRM), and relapse. Changes in nutritional status, based on laboratory parameters, were also examined. Underweight patients had significantly lower early and overall survival and greater NRM. Very obese patients had increased NRM, which was associated with the intensity of conditioning regimen. With long-term follow-up, increasing NRM was associated with both underweight and obese patients compared with normal-weight individuals. Changes in serum protein and albumin levels did not correlate with BMI. Although enteral nutrition is now recommended for some undernourished patients, the efficacy of enteral or parenteral nutrition has not been well studied. For obese patients, there are no guidelines regarding weight loss before transplantation, and acute weight loss in the pretransplantation period may be detrimental.

Age-dependent prognostic value of body mass index for non-metastatic clear cell renal cell carcinoma: A large multicenter retrospective analysis

BACKGROUND AND OBJECTIVES

The prognostic value of obesity is unestablished for renal cell carcinoma. We assessed the age-dependent prognostic value of body mass index (BMI) in a large multicenter cohort of patients with non-metastatic clear cell renal cell carcinoma (nm-cRCC).

METHODS

This study evaluated 2092 patients with nm-cRCC who underwent surgery with curative intent at five Korean institutions between 2001 and 2014.

RESULTS

There was no significant difference in BMI between the young (<45 years) and older patients (≥45 years) (P = 0.398). Among older patients, high BMI (≥25 kg/m² ) was associated with better 5-year rates of recurrence-free survival (RFS) and cancer-specific survival (CSS) (P = 0.003 and 0.004, respectively), and multivariate analysis confirmed that high BMI was independently associated with better RFS and CSS (RFS hazard ratio [HR]: 0.617, P = 0.005; CSS HR: 0.588, P = 0.024). However, among young patients, there were no significant BMI-related differences in the 5-year RFS and CSS rates (P = 0.457 and 0.420, respectively), and high BMI was not independently associated with RFS or CSS (P = 0.822 and 0.749, respectively).

CONCLUSIONS

Among patients with nm-cRCC, high BMI was associated with a favorable prognosis among older patients but not among young patients. Therefore, the relationship between obesity and nm-cRCC prognosis might vary according to age.

Pharmacokinetic and clinical outcomes when ideal body weight is used to dose busulfan in obese hematopoietic stem cell transplant recipients

Weight-based dosing of intravenous busulfan is widely used in hematopoietic cell transplantation. However, a variety of dosing weights have been described. The objective of this retrospective study was to determine the pharmacokinetic impact of using ideal body weight as the initial dosing weight in obese as compared to non-obese transplant recipients. The secondary objectives were to describe the use of alternative dosing weights, the impact on survival, and the rates of toxicities. The mean steady-state concentration was 779.3 ng/mL (n = 82) in the non-obese cohort and 673.7 ng/mL (n = 63) in the obese cohort (p < 0.001). A smaller proportion of concentrations were below goal in the non-obese cohort (10% vs. 41%, p < 0.001). Ideal body weight and adjusted body weights with a 25 and 40% correction factor are appropriate in non-obese patients; adjusted body weights with a 25 and 40% correction factor are appropriate in obese patients. There was no difference in overall survival (p = 0.18); there was a difference in median progression-free survival (1078 vs. 500 days, p = 0.045) in the non-obese compared to obese cohorts. The use of ideal body weight to dose busulfan resulted in lower steady-state concentrations, a larger proportion of subtherapeutic concentrations, and worse progression-free survival in obese patients.

The obesity paradox in cancer: clinical insights and perspectives

A series of evidence demonstrated that obesity represents an established risk factor for an increase in the incidence of multiple cancer types and for poor cancer survival. Nevertheless, recent studies suggested that, in a series of cancers, patients with a normal body mass index (BMI) have worse outcomes than obese patients. This phenomenon, named 'obesity paradox' or 'reverse epidemiology' in cancer, is not well understood and presents controversial aspects. Therefore, this review aims to explore the available studies concerning the relationship between obesity and cancer incidence or survival and to highlight the hypothetical explanations and the methodological framework. In this regard, we underline the limits of BMI as a potential marker of adiposity and the relevance to assessing body composition, beyond the body size. Further studies are needed to define the impact of obesity in cancer patients, to tailor weight management after cancer diagnosis and to hopefully improve overall clinical outcome.

Variability of nutritional practices in peritransplant period after allogeneic hematopoietic stem cell transplantation: a survey by the Complications and Quality of Life Working Party of the EBMT

Recommendations on screening and nutritional support for patients undergoing hematopoietic stem cell transplantation (HSCT) have been presented by international nutritional societies, but nutritional practices remain poorly standardized. Following the general policy of the European Society for Blood and Marrow Transplantation (EBMT) to standardize transplantation procedures, the Complications and Quality of Life Working Party and Nursing Research Group carried out a survey among all EBMT centers about their current nutritional practices. The aim of this study was to better understand current practices, differences from available guidelines, and possible barriers for recommended nutritional therapy. Responses from 90 centers (19%) from 23 countries were received. We observed a marked variability in nutritional care between EBMT centers and a substantial lack of standardized operating procedures in screening patients for malnutrition and management of gastrointestinal GVHD. Furthermore, our study confirmed neutropenic diet as standard of care in most centers as well a preference for parenteral nutritional support over enteral. On the basis of these findings, future EBMT efforts will focus on better implementation of international nutritional guidelines into clinical practice.

A role of low dose chemical mixtures in adipose tissue in carcinogenesis

The Halifax project recently hypothesized a composite carcinogenic potential of the mixture of low dose chemicals which are commonly encountered environmentally, yet which are not classified as human carcinogens. A long neglected but important fact is that adipose tissue is an important exposure source for chemical mixtures. In fact, findings from human studies based on several persistent organic pollutants in general populations with only background exposure should be interpreted from the viewpoint of chemical mixtures because serum concentrations of these chemicals can be seen as surrogates for chemical mixtures in adipose tissue. Furthermore, in conditions such as obesity with dysfunctional adipocytes or weight loss in which lipolysis is increased, the amount of the chemical mixture released from adipose tissue to circulation is increased. Thus, both obesity and weight loss can enhance the chance of chemical mixtures reaching critical organs, however paradoxical this idea may be when fat mass is the only factor considered. The complicated, interrelated dynamics of adipocytes and chemical mixtures can explain puzzling findings related to body weight among cancer patients, including the obesity paradox. The contamination of fat in human diet with chemical mixtures, occurring for reasons similar to contamination of human adipose tissue, may be a missing factor which affects the association between dietary fat intake and cancer. The presence of chemical mixtures in adipose tissue should be considered in future cancer research, including clinical trials on weight management among cancer survivors.

Unlocking the Complex Flavors of Dysgeusia after Hematopoietic Cell Transplantation

Dysgeusia is a frequently occurring symptom after hematopoietic cell transplantation (HCT) that has important long-term effects on physical, nutritional, and immunologic recovery, as well as on quality of life. Despite the relevance of this symptom, the study of dysgeusia in patients undergoing HCT has been limited, owing in part to its complexity. In this article, we review normal taste function and its clinical evaluation, discuss how dysgeusia uniquely affects patients undergoing HCT, and examine distinct, transplantation-related contributors to dysgeusia that may help elucidate strategies to ultimately reduce this symptom burden after transplantation.

Revisiting nutritional support for allogeneic hematologic stem cell transplantation-a systematic review

In 2009, the American Society of Parenteral and Enteral Nutrition and its European counterpart (Euopean Society for Parenteral and Enteral Nutrition) published guidelines regarding nutritional support of patients with hematologic stem cell transplantation. Our aim was to do an up-to-date literature review regarding benefit of nutritional interventions and treatment recommendations. We searched MEDLINE, EMBASE and Cochrane Library for interventional and observational clinical studies. We extracted data based on a predefined case report form and assessed bias. Out of 459 potential abstracts, 13 studies of mostly moderate quality with a total of 18 167 patients were included. Two very large trials reported negative associations of malnutrition and survival, transplant-related mortality and relapse risk. Some trials found enteral nutrition (EN) to be as effective as parenteral nutrition (PN) with lower complication rates. In addition, EN was associated with better survival, less acute GvHD and faster neutrophil recovery. A neutropenic diet was not superior regarding overall survival, but in contrast resulted in higher infection risk. Current moderate quality studies show negative associations of malnutrition and clinical outcomes, with EN being superior to PN. There was no benefit of neutropenic diets. Large, randomized controlled studies are needed to better understand optimal nutritional support in this patient population.

The Obesity Paradox in Cancer: a Review

There is a common perception that excess adiposity, commonly approximated by body mass index (BMI), is associated with reduced cancer survival. A number of studies have emerged challenging this by demonstrating that overweight and early obese states are associated with improved survival. This finding is termed the "obesity paradox" and is well recognized in the cardio-metabolic literature but less so in oncology. Here, we summarize the epidemiological findings related to the obesity paradox in cancer. Our review highlights that many observations of the obesity paradox in cancer reflect methodological mechanisms including the crudeness of BMI as an obesity measure, confounding, detection bias, reverse causality, and a specific form of the selection bias, known as collider bias. It is imperative for the oncologist to interpret the observation of the obesity paradox against the above methodological framework and avoid the misinterpretation that being obese might be "good" or "protective" for cancer patients.

Adjusting Cyclophosphamide Dose in Obese Patients with Lymphoma Is Safe and Yields Favorable Outcomes after Autologous Hematopoietic Cell Transplantation

No clear dosing guidelines exist for cyclophosphamide (Cy) dose adjustments in obese patients treated with high-dose chemoradiotherapy followed by autologous hematopoietic cell transplantation (HCT). We prospectively compared the outcomes of high-dose Cy/total body irradiation (TBI) conditioning in 147 non-Hodgkin lymphoma (NHL) patients in 3 weight groups: nonobese (<120% ideal body weight [IBW]; n = 72), overweight (120% to 149% IBW; n = 46), and obese (≥150% IBW; n = 29). Nonobese and overweight patients received Cy (120 mg/kg of total body weight, intravenously) and TBI (1320 cGy), whereas obese patients (median body mass index, 36) received an adjusted Cy dose based on IBW plus 50% of the difference between total body weight and IBW (AdjBW50). The median patient age was 57 years (range, 19 to 73). The most common diagnoses were diffuse large B cell lymphoma (n = 57) and mantle cell lymphoma (n = 51). Three-year overall survival was 61% (95% confidence interval [CI], 48% to 72%) for nonobese patients, 68% (95% CI, 52% to 82%) for overweight patients, and 80% (95% CI, 62% to 93%) for obese patients. Cumulative incidence of relapse (48%, 43%, and 38%, respectively) and nonrelapse mortality (∼4%) were similar in all groups. Hemorrhagic cystitis and cardiac toxicity were rare events. Our data show that the AdjBW50 formula can be safely and effectively used for Cy dose adjustments in obese patients treated for NHL with high-dose Cy/TBI conditioning followed by autologous HCT.

Association between body mass index at diagnosis and pediatric leukemia mortality and relapse: a systematic review and meta-analysis

Obesity is a risk factor for mortality and relapse of certain cancers. However, existing evidence for pediatric leukemia is inconsistent. The aim of this systematic review and meta-analysis was to evaluate the association between obesity at diagnosis and pediatric acute leukemia mortality and relapse. This study systematically searched MEDLINE and EMBASE from inception to February 5, 2015. Random-effect models were used to generate pooled estimates of study-specific hazard ratios (HR) and 95% confidence intervals (CI). Eleven studies were included. An increased risk of mortality with a high BMI at diagnosis was observed (overall survival: HR=1.30, 95% CI=1.16-1.46 and event-free survival: HR=1.46, 95% CI=1.29-1.64). Only two studies reported HR for relapse; one reported a reduced risk, while the other reported an increased risk. A high BMI at diagnosis is associated with poor overall and event-free survival among pediatric acute leukemia patients. Targeted therapeutic approaches for obese pediatric leukemia patients may potentially improve survival outcomes.

Systematic Nutritional Support in Allogeneic Hematopoietic Stem Cell Transplant Recipients

Allogeneic hematopoietic stem cell transplantation (HSCT) has become an established treatment modality for various hematological diseases. However, in allogeneic HSCT, patients often suffer from severe gastrointestinal complications caused by the conditioning regimen and acute/chronic graft-versus-host disease, which requires support by multidisciplinary nutritional support teams (NST). In addition, pretransplantation nutritional status can affect the clinical outcome after allogeneic HSCT. Therefore, it is important to refer the patient to a NST when becoming aware of nutritional problems before allogeneic HSCT. It is also important to follow nutritional status over the long term, as patients often suffer from various nutritional problems, such as malnutrition and metabolic syndrome, even late after allogeneic HSCT. In summary, NST can contribute to the improvement of nutritional status and possibly prognosis at every stage before and after allogeneic HSCT. Here, we aim to give a comprehensive overview of current understanding about nutritional support in allogeneic HSCT and try to provoke a constructive discussion to stimulate further investigation.

Impact of body mass index on pulmonary complications in patients with non-Hodgkin lymphoma treated with hematopoietic stem cell transplant

The objective of this study was to examine the association between body mass index (BMI) and the incidence of pulmonary complications (PCs) after hematopoietic stem cell transplant (HCT). We reviewed 398 adult patients with non-Hodgkin lymphoma (NHL) who received autologous or allogeneic HCT between 1993 and 1997. BMI was classified as normal (18.5 < BMI ≤ 24.9), overweight (24.9 < BMI ≤ 30) and obese (BMI > 30). Multivariate logistic regression was used to analyze the relationship between BMI and presence of PCs within 100 days post-HCT while adjusting for patient-, disease- and transplant-related variables. The incidence of PCs within 100 days post-HCT was 32% (n = 129). Median BMI was 25.4 (range: 18.6-52.2). Median age was 48.8 years (range: 19.5-73.6 years). Multivariate analysis failed to show significant association between BMI and PCs. However, a total body irradiation (TBI)-based conditioning regimen was associated with lower rate of PCs.

Outcomes after autologous SCT in lymphoma patients grouped by weight

Obesity continues to be an increasing global health issue contributing to the complexity of chemotherapy dosing in the field of SCT. Investigation into the optimal dosing weight used to calculate chemotherapy doses in obese patients undergoing SCT is limited and inconclusive. Our single-center, retrospective study compared safety and efficacy outcomes by body mass index (BMI) for 476 adult lymphoma patients who underwent auto-SCT with a myeloablative chemotherapeutic regimen of BU, CY and etoposide dosed using adjusted body weight. Three weight groups categorized based on BMI were defined: normal/underweight ⩽24.9 kg/m(2), overweight 25-29.9 kg/m(2) and obese ⩾30 kg/m(2). Severity of mucositis, incidence of secondary malignancy, incidence of bacteremia and median hospital length of stay did not differ among the groups. The median times to absolute neutrophil count and platelet recovery were 10 days (P=0.75) and 14 days (P=0.17), respectively. Obese patients had a lower 100-day mortality compared with other weight groups, although this did not translate into an OS benefit. OS and disease relapse were similar among the groups. Our study demonstrates that use of adjusted body weight to calculate chemotherapy doses does not negatively have an impact on outcomes in obese patients undergoing auto-SCT with BU, CY and etoposide.

Baseline body mass index among children and adults undergoing allogeneic hematopoietic cell transplantation: clinical characteristics and outcomes

Obesity is an important public health problem that may influence the outcomes of hematopoietic cell transplantation (HCT). We studied 898 children and adults receiving first-time allogeneic hematopoietic SCTs between 2004 and 2012. Pretransplant body mass index (BMI) was classified as underweight, normal weight, overweight or obese using the WHO classification or age-adjusted BMI percentiles for children. The study population was predominantly Caucasian, and the median age was 51 years (5 months-73 years). The cumulative 3-year incidence of nonrelapse mortality (NRM) in underweight, normal weight, overweight and obese patients was 20%, 19%, 20% and 33%, respectively. Major causes of NRM were acute and chronic GVHD. The corresponding incidence of relapse was 30%, 41%, 37% and 30%, respectively. Three-year OS was 59%, 48%, 47% and 43%, respectively. Multivariate analysis showed that obesity was associated with higher NRM (hazard ratio (HR) 1.43, P=0.04) and lower relapse (HR 0.65, P=0.002). Pretransplant plasma levels of ST2 and TNFR1 biomarkers were significantly higher in obese compared with normal weight patients (P=0.04 and P=0.05, respectively). The increase in NRM observed in obese patients was partially offset by a lower incidence of relapse with no difference in OS.

Chemotherapy dose adjustment for obese patients undergoing hematopoietic stem cell transplantation: a survey on behalf of the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation

BACKGROUND

Appropriate chemotherapy dosing for obese patients with malignant diseases is a significant challenge because limiting chemotherapy doses in these patients may negatively influence outcome. There is a paucity of information addressing high-dose chemotherapy in obese patients undergoing hematopoietic stem cell transplantation (HSCT).

METHODS

The Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation (EBMT) designed an electronic survey to assess current practice of dose adjustment of chemotherapy in obese patients undergoing HSCT.

RESULTS

A total of 56 EBMT centers from 27 countries responded to the online survey. Overall, 45 centers declared that they routinely adjust chemotherapy doses for obese patients (80.5%), and only 11 (19.5%) declared they do not adjust dose. Among the former group, most used body mass index as the parameter for defining obesity (28 centers, 62%). The method for determining the weight for chemotherapy calculation was actual body weight (ABW) in 16 centers, ideal body weight (IBW) in 10 centers, IBW plus 25% of the difference between IBW and ABW in 16 centers, and other methods for the rest. Among centers that used dose adjustment, 44% also capped the dose at 2 m(2) for a chemotherapy dose based on body surface area (BSA), whereas 56% did not cap. Interestingly, most of the centers (9 of 11) that did not adjust dose for weight also did not cap the BSA at 2 m(2).

CONCLUSION

This EBMT survey revealed large diversity among transplant centers regarding dose-adjustment practice for high-dose conditioning chemotherapy. Our next step is to analyze outcomes of transplantation according to dose-adjustment practice and, subsequently, to formulate a methodology for future prospective studies.

Effectiveness and toxicity of high-dose cyclophosphamide in obese versus non-obese patients receiving allogeneic hematopoietic stem cell transplant

PURPOSE

To determine if there is a difference in toxicity and effectiveness between obese and non-obese patients who receive high-dose cyclophosphamide (Cy) prior to allogeneic hematopoietic stem cell transplant (allo-HCT).

METHODS

Patients were included in this study if they were at least 18 years of age and received high-dose Cy in combination with total body irradiation (CyTBI) or busulfan (BuCy) prior to allo-HCT between 1 January 2008 and 29 February 2012. The primary endpoint was the difference in overall toxicity between obese and non-obese patients. Secondary objectives examined differences in effectiveness between groups assessed by relapse at day +100, relapse at 1 year, death at 1 year, chimerisms at days +30, +60, and +90, and incidence of acute graft versus host disease (aGVHD).

RESULTS

Sixty-one patients met the inclusion criteria, 28 obese and 33 non-obese. Overall toxicity was greater in obese patients compared to non-obese patients (82% vs. 52%, OR 4.3 [95% CI 1.3-14.1]; p = 0.01), which was driven by a greater incidence of renal dysfunction (79% vs. 48%, OR 3.9 [95% CI 1.3-12.1]; p = 0.02). There were no differences in rates of grade 3 or 4 toxicity, hepatic dysfunction, or any measure of effectiveness between groups.

CONCLUSION

Obese patients receiving high-dose Cy and allo-HCT are at increased risk for toxicity, although there appears to be no difference in the rate of relapse or survival between obese and non-obese patients.

Impact of pretransplant body mass index on the clinical outcome after allogeneic hematopoietic SCT

To elucidate the impact of pretransplant body mass index (BMI) on the clinical outcome, we performed a retrospective study with registry data including a total of 12 050 patients (age ⩾18 years) who received allogeneic hematopoietic SCT (HSCT) between 2000 and 2010. Patients were stratified as follows: BMI<18.5 kg/m(2), Underweight, n=1791; 18.5⩽BMI<25, Normal, n=8444; 25⩽BMI<30, Overweight, n=1591; BMI⩾30, Obese, n=224. The median age was 45 years (range, 18-77). A multivariate analysis showed that the risk of relapse was significantly higher in the underweight group and lower in the overweight and obese groups compared with the normal group (hazard ratio (HR), 1.16, 0.86, and 0.74, respectively). The risk of GVHD was significantly higher in the overweight group compared with the normal group. The risk of non-relapse mortality (NRM) was significantly higher in the overweight and obese group compared with the normal group (HR 1.19 and HR 1.43, respectively). The probability of OS was lower in the underweight group compared with the normal group (HR 1.10, P=0.018). In conclusion, pretransplant BMI affected the risk of relapse and NRM after allogeneic HSCT. Underweight was a risk factor for poor OS because of an increased risk of relapse. Obesity was a risk factor for NRM.

Conditioning chemotherapy dose adjustment in obese patients: a review and position statement by the American Society for Blood and Marrow Transplantation practice guideline committee

Hematopoietic stem cell transplantation (HCT) is a potentially life-saving therapy for patients with malignant and nonmalignant disease states. This article reviews the current published literature on the dosing of pharmacologic agents used for HCT preparative regimens with specific focus on the obese patient population. The review found that dose adjustments for obesity have, to date, been based empirically or extrapolated from published data in the nontransplantation patient population. As a result, the Committee determined that clear standards or dosing guidelines are unable to be made for the obese population because Level I and II evidence are unavailable at this time. Instead, the Committee provides a current published literature review to serve as a platform for conditioning agent dose selection in the setting of obesity. A necessary goal should be to encourage future prospective trials in this patient population because further information is needed to enhance our knowledge of the pharmacokinetics and pharmacodynamics of conditioning agents in the setting of obesity.

Effect of body mass in children with hematologic malignancies undergoing allogeneic bone marrow transplantation

The rising incidence of pediatric obesity may significantly affect bone marrow transplantation (BMT) outcomes. We analyzed outcomes in 3687 children worldwide who received cyclophosphamide-based BMT regimens for leukemias between 1990 and 2007. Recipients were classified according to age-adjusted body mass index (BMI) percentiles as underweight (UW), at risk of UW (RUW), normal, overweight (OW), or obese (OB). Median age and race were similar in all groups. Sixty-one percent of OB children were from the United States/Canada. Three-year relapse-free and overall survival ranged from 48% to 52% (P = .54) and 55% to 58% (P = .81) across BMI groups. Three-year leukemia relapses were 33%, 33%, 29%, 25%, and 21% in the UW, RUW, normal, OW, and OB groups, respectively (P < .001). Corresponding cumulative incidences for transplant-related mortality (TRM) were 18%, 19%, 21%, 22%, and 28% (P < .01). Multivariate analysis demonstrated a decreased risk of relapse compared with normal BMI (relative risk [RR] = 0.73; P < .01) and a trend toward higher TRM (RR = 1.28; P = .014). BMI in children is not significantly associated with different survival after BMT for hematologic malignancies. Obese children experience less relapse posttransplant compared with children with normal BMI; however, this benefit is offset by excess in TRM.