Trends in allogeneic hematopoietic cell transplantation survival using population-based descriptive epidemiology method: analysis of national transplant registry data.

Prognosis for patients undergoing hematopoietic cell transplantation (HCT) has been improving. Short-term survival information, such as crude survival rates that consider deaths immediately after the transplantation, may not be sufficiently useful for assessing long-term survival. Using the data of the Japanese HCT registry, the net survival rate of patients who survived for a given period was determined according to age, disease, and type of transplant. We included a total of 41,716 patients who received their first allogeneic hematopoietic cell transplantation between 1991 and 2015. For each disease, age group, graft source subcategory, net survival was calculated using the Pohar-Perme method, and 5-year conditional net survival (CS) was calculated. Ten-year net survivals of total patient cohort were 41.5% and 47.4% for males and females, respectively. Except for myelodysplastic syndrome, multiple myeloma, and adult T-cell leukemia/lymphoma, 5-year CS for 5-year transplant survivors exceeded 90%. CS was especially high for aplastic anemia, of which was over 100% for children and younger adults receiving cord blood, suggesting that these patients have similar longevity to an equivalent group from the general population. These findings provide useful information for long-term survival, and can serve as benchmark for comparisons among registries, including other cancers.

Evaluation of two-stage hepatectomy using portal vein embolization for colorectal liver metastasis: a retrospective nationwide cohort survey in Japan.

INTRODUCTION: Two-stage hepatectomy (TSH) enables patients to undergo surgery for colorectal liver metastasis (CRLM) which one-stage hepatectomy cannot remove. Although the outcome of TSH has been reported, there is no original report from Japan. The aim of this retrospective study was to evaluate the outcome of TSH in Japanese patients with CRLM. METHODS: We conducted a retrospective cohort study using the nationwide database that included clinical information of 12,519 patients treated with CRLM between 2005 and 2017 in Japan. The primary outcome measure was overall survival. The second outcome measure was progression-free survival. Fisher's exact test, chi-squared test and Mann-Whitney U test were conducted to examine an intergroup difference. Univariate and multivariate analyses were performed using Cox regression model. Survival analysis was performed by Kaplan-Meier method and log-rank test. RESULTS: Of the database, 53 patients undergoing TSH using portal vein embolization (PVE) were identified and analyzed. Their morbidity and in-hospital mortality rate at the second hepatectomy were 26.4% and 0.0%. The mean observation period was 21.8 months. The estimated 1-, 3- and 5-year overall survival rate were 92.5%, 70.8% and 34.7%. Multivariate analyses showed that more than 10 liver nodules significantly increased the mortality risk by 4.2-fold (95%CI 1.224-14.99, P= 0.023). Survival analysis revealed that repeat hepatectomy for disease progression after TSH was superior to chemotherapy in overall survival (mean: 49.6 vs. 18.7, months, P= 0.004). CONCLUSION: In the Japanese cohort, TSH was confirmed to be a safety procedure with acceptable survival outcome. More than 10 liver nodules may be a predictor for unfavorable outcome of patients with CRLM undergoing TSH. Furthermore, repeat hepatectomy can be a salvage treatment for resectable intrahepatic recurrence after TSH.

A higher CD34 + cell dose correlates with better event-free survival after KIR-ligand mismatched cord blood transplantation for childhood acute myeloid leukemia.

Although killer Ig-like receptor ligands (KIR-L) mismatch has been associated with alloreactive natural killer cell activity and potent graft-versus-leukemia (GVL) effect among adults with acute myeloid leukemia (AML), its role among children with AML receiving cord blood transplantation (CBT) has not been determined. We conducted a retrospective study using a nationwide registry of the Japanese Society for Transplantation and Cellular Therapy. Patients who were diagnosed with de novo non-M3 AML and who underwent their first CBT in remission between 2000 and 2021 at under 16 years old were included. A total of 299 patients were included; 238 patients were in the KIR-L match group, and 61 patients were in the KIR-L mismatch group. The cumulative incidence rates of neutrophil recovery, platelet engraftment, and acute/chronic graft-versus-host disease did not differ significantly between the groups. The 5-year event-free survival (EFS) rate was 69.8% in the KIR-L match group and 74.0% in the KIR-L mismatch group (p = 0.490). Stratification by CD34 + cell dose into four groups revealed a significant correlation between CD34 + cell dose and EFS in the KIR-L mismatch group (p = 0.006) but not in the KIR-L match group (p = 0.325). According to our multivariate analysis, KIR-L mismatch with a high CD34 + cell dose (≥ median dose) was identified as an independent favorable prognostic factor for EFS (hazard ratio = 0.19, p = 0.029) and for the cumulative incidence of relapse (hazard ratio = 0.09, p = 0.021). Our results suggested that higher CD34 + cell doses are crucial for achieving a potent GVL effect in the context of KIR-L-mismatched CBT.

The effect of center experience on allogeneic hematopoietic cell transplantation outcomes in acute myeloid leukemia.

This study aimed to address the prognostic impact of center experience based on the data of 7821 adults with acute myeloid leukemia who underwent allogeneic hematopoietic cell transplantation (HCT) from 2010 to 2019 in Japan, where medical care was provided within a uniform healthcare system. Center experience was defined based on the number of allogeneic HCTs performed for any indication during the study period, by which centers were divided into low-, intermediate-, and high-volume centers. After adjusting for known confounding factors, the risk of overall mortality was lowest for the high-volume centers and highest for the low-volume centers, with the difference between the center categories attributed primarily to the risk of relapse. Patients transplanted at high-volume centers had higher risks of acute and chronic graft-versus-host diseases but without an increased risk of non-relapse mortality (NRM). These findings reveal the presence of a center effect in allogeneic HCT conducted during the past decade in Japan, highlighting the difference in relapse based on center experience. The weaker effect on NRM compared with that on relapse suggests that the transplantation care quality is becoming equalized across the country.

Impact of Center Volume on Chronic Graft Versus Host Disease in Patients With Allogeneic Stem Cell Transplantation.

Chronic graft-versus-host disease (cGVHD) is a complication of allogeneic hematopoietic stem cell transplantation (HSCT), negatively impacting quality of life (QoL) and increasing the risk of death. Complexity in cGVHD diagnosis and treatment causes significant variations in cGVHD management strategies across medical centers and physicians despite the existence of published guidelines. Thus, we hypothesized that center volume is associated with cGVHD incidence and outcomes after cGVHD develops. This study aimed to evaluate the effect of center volume on the incidence of cGVHD in patients who underwent HSCT and outcomes in patients with cGVHD. Our retrospective study included 28,786 patients who underwent their first HSCT (overall cohort) and 7664 who developed cGVHD (cGVHD cohort). We categorized institutions into quartiles (very low, low, high, and very high) using the number of HSCTs performed during the study period. We assessed cGVHD incidence in overall cohort and overall survival (OS) in cGVHD cohort. The very high-volume group showed significantly higher cGVHD incidence (adjusted hazard ratio [HR], 1.38; 95% confidence interval [CI]: 1.30 to 1.46) compared to the very low-volume group. However, the cGVHD incidence was similar among very low-, low- and high-volume groups. Low, high, and very high-volume groups showed significantly higher OS with adjusted HRs of 0.83 (95% CI: 0.73 to 0.94), 0.69 (95% CI: 0.61 to 0.79), and 0.68 (95% CI: 0.60 to 0.76), respectively, compared with the very low-volume group. In conclusion, we revealed a higher incidence of cGVHD in the very high-volume group and a poor survival outcome in the very low-volume group in patients with cGVHD.

Cancer incidence and type of treatment hospital among children, adolescents, and young adults in Japan, 2016-2018.

Cancer in children, adolescents, and young adults (AYAs) although rare, is the leading disease-specific cause of death in Japan. This study aims to investigate cancer incidence and type of treatment hospital among children and AYAs in Japan. Cancer incidence data (2016-2018) for those aged 0-39 years were obtained from the Japanese population-based National Cancer Registry. Cancer types were classified according to the 2017 update of the International Classification of Childhood Cancer (Third Edition), and AYA Site Recode 2020 Revision. Cases were also categorized into three groups: those treated at core hospitals for pediatric cancer treatment (pediatric cancer hospitals [PCHs]), those treated at designated cancer care hospitals, and those treated at nondesignated hospitals. The age-standardized incidence rate was 166.6 (per million-person years) for children (age 0-14 years) and 579.0 for AYAs (age 15-39 years) (including all cancers and benign or uncertain-behavior central nervous system [CNS] tumors). The type of cancer varied with age: hematological malignancies, blastomas, and CNS tumors were common in children under 10 years, malignant bone tumors and soft tissue sarcomas were relatively common in teenagers, and in young adults over 20 years, carcinomas in thyroid, testis, gastrointestinal, female cervix, and breast were common. The proportion of cases treated at PCHs ranged from 20% to 30% for children, 10% or less for AYAs, and differed according to age group and cancer type. Based on this information, the optimal system of cancer care should be discussed.

Ecological aspect of the larval parasitoid Diadegma hiraii (Hymenoptera: Ichneumonidae) as a potential biological control agent of soybean pod borer Leguminivora glycinivorella (Lepidoptera: Tortricidae).

The larval parasitoid Diadegma hiraii (Kusigemati) was evaluated as a potential biological control agent of the soybean pod borer, Leguminivora glycinivorella (Matsumura). The timing of adult emergence after overwintering was ascertained, and land-use factors that enhance population density were analyzed. Host cocoons were collected and exposed to different temperatures and photoperiod regimes. Subsequently, the emergence of parasitoid was monitored. Land-use types were categorized into 4 land-use types (Poaceae, Fabaceae, Brassicaceae, and forest). Adult parasitoid emergence was dependent on temperature, but largely unaffected by photoperiod. The estimated emergence time of parasitoid was 3 months before the occurrence of the host, suggesting that the overwintered generation may lay eggs in alternate hosts. Parasitism rate was positively correlated with the area covered by Poaceae plants within a 500-m radius of the soybean field. Based on the results of the overwintering ecology and landscape analysis, D. hiraii probably completes its life cycle in the agroecosystems. The parasitoid's effectiveness as a biological control agent may be influenced by the arrangement of land-use types in the agroecosystems surrounding soybean fields. However, the pest control provided by D. hiraii is limited because of approximately 30% of parasitism rate. Consequently, a combination of this species and cultural control and/or other biological control agents is suggested for sustainable soybean cultivation.

Camera-trapping estimates of the relative population density of Sympetrum dragonflies: application to multihabitat users in agricultural landscapes.

Although camera trapping has been effectively used for wildlife monitoring, its application to multihabitat insects (i.e., insects requiring terrestrial and aquatic ecosystems) is limited. Among such insects, perching dragonflies of the genus Sympetrum (darter dragonflies) are agroenvironmental indicators that substantially contribute to agricultural biodiversity. To examine whether custom-developed camera traps for perching dragonflies can be used to assess the relative population density of darter dragonflies, camera trapping, a line-transect survey of mature adult dragonflies, and a line-transect survey of exuviae were conducted for three years in rice paddy fields in Japan. The detection frequency of camera traps in autumn was significantly correlated with the density index of mature adults recorded during the transect surveys in the same season for both Sympetrum infuscatum and other darter species. In analyses of camera-detection frequency in autumn and exuviae in early summer, a significant correlation was observed between the camera-detection frequency of mature adults and the exuviae-density index in the following year for S. infuscatum; however, a similar correlation was not observed for other darter species. These results suggest that terrestrial camera trapping has the potential to be effective for monitoring the relative density of multihabitat users such as S. infuscatum, which shows frequent perching behavior and relatively short-distance dispersal.

Predacious Natural Enemies Associated With Suppression of Onion Thrips, Thrips tabaci (Thysanoptera: Thripidae), in Intercropped Onion-Barley Agroecosystems.

The effects of two possible factors, prevention of pest immigration and enhancement of natural enemies, in suppressing onion thrips, Thrips tabaci L., were estimated in a small-scale experimental system of spring-planted onions intercropped with barley. The population dynamics of the thrips and their potential predatory natural enemies were investigated in four treatments: control (bare ground), insect net barrier, and onion-barley intercropping with or without trimming. We found that intercropping significantly suppressed onion thrips. It is unlikely that this effect was due to the prevention of thrip immigration because they seemed to move over the camouflage and/or physical barriers of the barley and the net barrier surrounding the onions easily. Intercropping with barley significantly increased hoverfly (Syrphidae) larvae numbers on onion leaves, and that of some groups of ground-dwelling predators such as large carnivorous ground beetles (Carabidae), ants (Formicidae), and wolf spiders (Lycosidae). We conclude that the suppression of thrips in this system was associated with the enhancement of hoverfly larvae abundance, mainly Sphaerophoria macrogaster (Thomson) (Syrphidae: Diptera) because they were observed together with thrips on onions and have been reported to predate thrips as well as aphids. Some hoverfly larvae on barley might move to nearby onions to search for new food sources and attack thrips.

Comprehensive data of 4502 patients newly diagnosed with colorectal liver metastasis between 2015 and 2017, and prognostic data of 2427 patients newly diagnosed with colorectal liver metastasis in 2013 and 2014: Third report of a nationwide survey in Japan.

To improve treatment outcomes in patients with colorectal liver metastasis (CRLM), the Joint Committee for Nationwide Survey on CRLM was established by the Japanese Society for Cancer of the Colon and Rectum and the Japanese Society of Hepato-Biliary-Pancreatic Surgery. The aim of the study was to evaluate transition in the characteristics and treatment strategy in CRLM patients and analyze prognostic factors using large-scale data. The present study summarizes the data of patients newly diagnosed between 2015 and 2017 and presents prognostic data of patients newly diagnosed in 2013 and 2014. Survival curves were generated by the Kaplan-Meier method and compared by log-rank test. Multivariate analyses were carried out using Cox proportional hazard modeling. The data of 4502 patients newly diagnosed with CRLM between 2015 and 2017 and the prognostic data of 2427 patients diagnosed in 2013 and 2014 are included. Regarding the 2013 and 2014 prognostic data, the 5-year overall survival (OS) rates of patients who underwent hepatectomy alone was 59.8%. Multivariate analyses identified age at diagnosis of CRLM ≥70 years, concomitant extrahepatic metastasis at diagnosis of CRLM, tumor depth of primary lesion ≥subserosa/pericolic or perirectal tissue, mutant KRAS status, number of CRLM ≥5, maximum diameter of CRLM >5 cm, and surgical curability R1/R2 as independent predictors of OS. Analysis of the latest nationwide database of patients diagnosed with CRLM revealed changes in patients and oncological characteristics, a transition in treatment strategy, and different independent prognosticators to those reported previously.

UBTF-internal tandem duplication as a novel poor prognostic factor in pediatric acute myeloid leukemia.

The prognosis of pediatric acute myeloid leukemia (AML) has improved via stratification therapy. However, relapse or death occurs in 30%-40% of cases. Novel genetic factors for pediatric AML need to be elucidated to improve prognosis. We detected recurrent internal tandem duplication in upstream binding transcription factor (UBTF-ITD) in 1.2% (6/503) of Japanese pediatric patients with de novo AML. No UBTF-ITD was detected in 175 adult patients with AML or in 65 cell lines that included 15 AML, 39 acute lymphoblastic leukemia, five chronic myeloid leukemia, and six neuroblastoma cell lines. All UBTF-ITDs were found in exon 13 and shared a duplicated region. UBTF-ITD was more frequently detected in patients with trisomy 8, FLT3-ITD, WT1 mutation, and/or high PRDM16 expression (trisomy 8, 3/6; FLT3-ITD, 5/6; WT1 mutation, 2/6; and high PRDM16 expression, 6/6). Gene expression patterns of patients with UBTF-ITD were similar to those of patients with NUP98::NSD1 or FUS::ERG. Survival analysis of the AML-05 cohort revealed that patients with UBTF-ITD had worse outcomes than those without UBTF-ITD (3-year event-free survival, 20% vs. 55%; 3-year overall survival, 40% vs. 74%). Moreover, among the 27 patients with trisomy 8, all three patients with UBTF -ITD had a poor prognosis resulting in early events (relapse or non-complete remission) within 1 year. Our findings suggest that UBTF-ITD may be a novel and significant prognostic factor for pediatric patients with AML.

Validation study of the JSHBPS nomogram for patients with colorectal liver metastases who underwent hepatic resection in the recent era - a nationwide survey in Japan.

BACKGROUND: The Japanese Society of Hepato-Biliary-Pancreatic Surgery (JSHBPS) nomogram was developed to predict disease-free survival in patients with colorectal liver metastases (CRLM) undergoing upfront hepatectomy. However, the utility of the nomogram in patients with resected CRLM remains unknown in the current situation in which treatment strategies are changing with advances in drugs. METHODS: Patients in the initial nomogram cohort (n = 727) and validation cohort (n = 2225) were divided into the upfront hepatectomy and preoperative chemotherapy groups. The nomogram was validated by measuring calibration and discrimination in the two cohorts. Calibration curves were plotted, and survival probabilities were compared. Finally, to quantify the discrimination power, we estimated the concordance index (C-index). RESULTS: In the upfront hepatectomy group, the C-index was 0.63, the suitable cutoff value of the Beppu score was 7, and adjuvant chemotherapy was significantly effective limited to high-risk patients (Beppu score ≥7). The C-index was 0.56 in the preoperative chemotherapy group. CONCLUSIONS: The JSHBPS nomogram remains beneficial for patients undergoing upfront hepatectomy in the recent era but is less effective for patients undergoing hepatectomy after chemotherapy. Patients with a Beppu score ≥7 showed high-risk recurrence, and adjuvant chemotherapy should be recommended for these patients.

Impact of human leukocyte antigen mismatch on outcomes after unrelated bone marrow transplantation in paediatric patients: A retrospective analysis by the JSTCT HLA working group.

The impact of human leukocyte antigen (HLA) mismatching at the HLA-A, -B, -C, and -DRB1 loci after unrelated bone marrow transplantation in paediatric patients with haematological malignancies has not been fully examined. Here, we analysed patients with haematological malignancies (all aged ≤15 years; n = 1330) who underwent a first unrelated bone marrow transplantation between 1993 and 2017 in Japan. The results show that although an HLA mismatch was significantly associated with a low relapse rate, it was also associated with higher non-relapse mortality. There was a significant association between HLA mismatch and low overall survival. Locus mismatch analysis revealed that, as in adults, an HLA-C mismatch had a significant negative impact on survival; however, in paediatric patients, an HLA-DRB1 mismatch did not have a negative impact, although these HLA mismatch effects are weakened in recent cases. Taken together, the results suggest that an HLA-matched donor should be the first candidate for paediatric patients; however, for patients without a matched sibling or matched unrelated donor, we can select an unrelated donor with a mismatch at HLA-DRB1 if available.

Estimating plant-insect interactions under climate change with limited data.

Climate change may disrupt species-species interactions via phenological changes in one or both species. To predict and evaluate the influence of climate change on these interactions, long-term monitoring and sampling over large spatial areas are required; however, funding and labor constraints limit data collection. In this study, we predict and evaluate the plant-insect interactions with limited data sets. We examined plant-insect interaction using observational data for development of the crop plant rice (Oryza sativa) and an effective accumulated temperature (EAT) model of two mirid bugs (Stenotus rubrovittatus and Trigonotylus caelestialium). We combined 11 years of records monitoring rice phenology and the predicted phenology of mirid bugs using spatially-explicit EAT models based on both spatially and temporally high resolutions temperature data sets, then evaluated their accuracy using actual pest damage records. Our results showed that the predicted interactions between rice and mirid bugs explained rice damage to some degree. Our approach may apply predicting changes to plant-insect interactions under climate change. As such, combining plant monitoring records and theoretical predictions of insect phenology may be effective for predicting species-species interactions when available data are limited.

Extrapolating potential crop damage by insect pests based on land use data: examining inter-regional generality in agricultural landscapes.

BACKGROUND: Inter-regional relationships between landscape factors and biological responses in natural conditions are important but difficult to predict because of the differences in each landscape context and local environment. To examine the inter-regional variability in relation to landscape factors and the biological response of an insect pest of rice, Stenotus rubrovittatus, we extrapolated a damage prediction model (the 'original model' of our previous study) for rice using land-use data. The 'original model' comprised as fixed factors the area of source habitat (i.e. pastures and graminoid-dominated fallow fields), soybean fields, and rice paddies within 300-m radii with research years as the random intercept. We hypothesized that the original model would be applicable to new regions, but the predictive accuracy would be reduced. We predicted that fitting a new extended model, adjusting the parameter coefficients of identical fixed factors of the 'original model,' and adding regional random intercepts would improve model performance (the 'extended model'). A field experiment was conducted in two regions that had a similar landscape context with the original region, each in a different year of four years in total. The proportion of rice damage and surrounding land use within a 300-m radius was investigated, and the data were applied to the models and the applicability and accuracy of the models were examined. RESULTS: When the 'original model' was assigned to the combined data from the original and extrapolated regions, the relationship between the observed and the predicted values was statistically significant, suggesting that there was an inter-regional common relationship. The relationship was not statistically significant if the model was applied only to the new regions. The extended model accuracy improved by 14% compared with the original model and was applicable for unknown data within the examined regions as demonstrated by three-fold cross validation. CONCLUSIONS: These results imply that in this pest-crop system, there is likely to be a common inter-regional biological response of arthropods because of landscape factors, although we need to consider local environmental factors. We should be able to apply such relationships to identify or prevent pest hazards by offering region-wide management options.

Clinical significance of RAS pathway alterations in pediatric acute myeloid leukemia.

RAS pathway alterations have been implicated in the pathogenesis of various hematological malignancies. However, their clinical relevance in pediatric acute myeloid leukemia (AML) is not well characterized. We analyzed the frequency, clinical significance, and prognostic relevance of RAS pathway alterations in 328 pediatric patients with de novo AML. RAS pathway alterations were detected in 80 (24.4%) of 328 patients: NF1 (n=7, 2.1%), PTPN11 (n=15, 4.6%), CBL (n=6, 1.8%), NRAS (n=44, 13.4%), KRAS (n=12, 3.7%). Most of these alterations in the RAS pathway were mutually exclusive also together with other aberrations of signal transduction pathways such as FLT3-ITD (P=0.001) and KIT mutation (P=0.004). NF1 alterations were frequently detected in patients with complex karyotype (P=0.031) and were found to be independent predictors of poor overall survival (OS) in multivariate analysis (P=0.007). At least four of seven patients with NF1 alterations had biallelic inactivation. NRAS mutations were frequently observed in patients with CBFB-MYH11 and were independent predictors of favorable outcomes in multivariate analysis (OS, P=0.023; event-free survival [EFS], P=0.037). Patients with PTPN11 mutations more frequently received stem cell transplantation (P=0.035) and showed poor EFS than patients without PTPN11 mutations (P=0.013). Detailed analysis of RAS pathway alterations may enable a more accurate prognostic stratification of pediatric AML and may provide novel therapeutic molecular targets related to this signal transduction pathway.

Intraspecific variations in life history traits of two pecky rice bug species from Japan: Mapping emergence dates and number of annual generations.

The mirid bugs Stenotus rubrovittatus and Trigonotylus caelestialium, which cause pecky rice, have become a threat to rice cultivation in Asia. Damage caused by these pests has rapidly become frequent since around 2000 in Japan. Their expansion pattern is not simple, and predicting their future spread remains challenging. Some insects with wide ranges have locally adapted variations in life-history traits. We performed laboratory rearing experiments to assess the geographical scale of intraspecific variations in life-history traits of S. rubrovittatus and T. caelestialium. The experiments were aimed at increasing the accuracy of occurrence estimates and the number of generations per year. These results were compared with previous research, and differences in development rates were observed between populations of different latitudes, but not of the same latitude. Finally, plotting the timing of adult emergence and the potential number of generations per year on maps with a 5-km grid revealed that they differed greatly locally at the same latitude. These maps can be used for developing more efficient methods of managing mirid bugs in integrated pest management.

Personalized prediction of overall survival in patients with AML in non-complete remission undergoing allo-HCT.

Allogenic hematopoietic stem cell transplantation (allo-HCT) is the standard treatment for acute myeloid leukemia (AML) in non-complete remission (non-CR); however, the prognosis is inconsistent. This study aimed to develop and validate nomograms and a web application to predict the overall survival (OS) of patients with non-CR AML undergoing allo-HCT (cord blood transplantation [CBT], bone marrow transplantation [BMT], and peripheral blood stem cell transplantation [PBSCT]). Data from 3052 patients were analyzed to construct and validate the prognostic models. The common significant prognostic factors among patients undergoing allo-HCT were age, performance status, percentage of peripheral blasts, cytogenetic risk, chemotherapy response, and number of transplantations. The conditioning regimen was a significant prognostic factor only in patients undergoing CBT. Compared with cyclophosphamide/total body irradiation, a conditioning regimen of ≥3 drugs, including fludarabine, with CBT exhibited the lowest hazard ratio for mortality (0.384; 95% CI, 0.266-0.554; p < 0.0001). A conditioning regimen of ≥3 drugs with CBT also showed the best leukemia-free survival among all conditioning regimens. Based on the results of the multivariable analysis, we developed prognostic models showing adequate calibration and discrimination (the c-indices for CBT, BMT, and PBSCT were 0.648, 0.600, and 0.658, respectively). Our prognostic models can help in assessing individual risks and designing future clinical studies. Furthermore, our study indicates the effectiveness of multi-drug conditioning regimens in patients undergoing CBT.