Low transplant-related mortality with allogeneic stem cell transplantation in elderly patients

[Combination of busulfan with increased-dose of fludarabine as conditioning regimen for MDS and MDS-AML patients with allo-HSCT]

目的

探讨白消安联合增加剂量氟达拉滨（Bu/ID-Flu）为主预处理方案进行异基因造血干细胞移植（allo-HSCT）治疗骨髓增生异常综合征（MDS）和MDS转化的急性髓系白血病（MDSAML）的疗效与安全性。

方法

回顾性分析Bu/ID-Flu预处理方案进行allo-HSCT治疗27例MDS和22例MDS-AML患者的临床资料。

结果

全部49例患者均达到造血重建。白细胞植活中位时间为13 (10~22) d，血小板植活中位时间为16 (8~66) d。Ⅱ~Ⅳ度急性移植物抗宿主病（GVHD）、出血性膀胱炎及肝静脉阻塞病的发生率分别为28.6%、14.3％和2.0%。移植后100 d和总体移植相关死亡率（TRM）分别为4.1 %（2/49）和8.2%（4/49）。中位随访14(1~92）个月，总生存（OS）率、无病生存（DFS）率分别为75.5%、73.5%。Kaplan-Meier分析示3年OS率、DFS率分别为（71.1±7.8）%、（66.7±8.3）%，复发率为16.3%。MDS、MDS-AML患者的OS率分别为81.5%（22/27）、68.2%（15/22），复发率分别为3.7%（1/27）、31.8%（7/22）。allo-HSCT前达完全缓解（CR）与未达CR的MDS-AML患者的OS率分别为83.3%（10/12）、50.0%（5/10），复发率分别为16.7%（2/12）、50.0%（5/10）。除化疗未达CR的MDS-AML患者（10例）外，其余39例患者的OS率及复发率分别为82.1 %（32/39）和7.7%（3/39）。单因素分析显示，移植前疾病状态是影响OS的高危因素（P=0.031），年龄、预处理中加入地西他滨、造血干细胞来源、HLA相合与否、供受者性别差异、输入CD34⁺细胞数和GVHD均不是影响OS的危险因素。

结论

应用Bu/ID-Flu为主的预处理方案对MDS和MDS-AML患者进行allo-HSCT，造血功能恢复迅速、植入稳定，并发症发生率和TRM较低。除MDS-AML化疗未达CR患者外，OS率较高且复发率较低。

Allogeneic stem cell transplantation in patients above 55: suggestion for a further stratification of the HCT-CI

INTRODUCTION

Allogeneic stem cell transplantation (alloSCT) has become available for elderly patients or for patients with comorbidities by introduction of reduced-intense conditioning. Comorbidity-related prognosis after alloSCT can be estimated by the hematopoietic cell transplantation comorbidity index (HCT-CI).

MATERIAL AND METHODS

The charts from 85 patients who have undergone 90 alloSCTs between 1999 and 2011 were analysed. Most patients received a dose-reduced conditioning and a graft from an unrelated donor. Patients were stratified for age, HCT-CI, cGvHD versus no cGvHD, and a modified HCT-CI with a further split high-risk score.

RESULTS

Age over 60 years did not affect the outcome. Manifestation of cGvHD improved the prognosis significantly. An additional stratification of the high-risk group of the HCT-CI revealed that even a fraction of these patients can have considerable benefit from an alloSCT. Furthermore, this high-risk collective could be clearly discriminated into two groups with different outcomes.

CONCLUSIONS

The investigation confirms that age is no absolute risk factor for alloSCT and demonstrates the heterogeneity of the high-risk group of the HCT-CI. A comprehensive investigation of an additional stratification is suggested. Furthermore, the authors encourage early withdrawal of immunosuppression, even in elderly patients and patients with comorbidities to permit graft-versus-leukaemia/lymphoma, since cGvHD is associated with a significantly better prognosis.

Immunosenescence does not abrogate engraftment of murine allogeneic bone marrow

BACKGROUND

Allogeneic bone marrow transplantation is under investigation for a range of nonmalignant indications, including tolerance induction through mixed chimerism. This strategy has so far been tested experimentally only in young recipients. Due to immunosenescence, older patients have an increase in memory T cells (TMEM) as well as other alterations to their immune system, which may influence the potential to induce tolerance. We therefore investigated the impact of immunosenescence on chimerism-based tolerance induction.

METHODS

Groups of young (2 months) and old (12 months) C57BL/6 recipients received BALB/c bone marrow under nonmyeloablative (3 Gy) and minimal (1 Gy) total body irradiation and treatment with costimulation blockade, T-cell depletion, or rapamycin. Multilineage chimerism, clonal deletion, and lymphocyte subsets were analyzed by flow cytometry. Tolerance was assessed by skin and heart grafts and enzyme-linked immunospot, intracellular cytokine, and mixed lymphocyte reaction assays.

RESULTS

Unexpectedly, chimerism and tolerance were established in old recipients with comparable-and in some cases increased-efficacy as in young recipients employing costimulation blockade-based or T-cell depletion-based conditioning with 1 or 3 Gy total body irradiation. TMEM reactivity in (naïve) old mice was augmented in response to polyclonal but not to allogeneic stimulation, providing a mechanistic underpinning for the susceptibility to chimerism induction despite increased TMEM frequencies. Tolerance in old recipients was associated with peripheral and central clonal deletion and a higher frequency of regulatory T cells.

CONCLUSION

Advanced age does not impair bone marrow engraftment, thereby widening the clinical potential of experimental protocols inducing transplantation tolerance through mixed chimerism.

Mucositis after reduced intensity conditioning and allogeneic stem cell transplantation

BACKGROUND

Therapyrelated mucositis is associated with considerable morbidity. This complication following allogeneic stem cell therapy (alloSCT) is less severe after reduced intense conditioning (RIC); however, even here it may be serious.

METHODS

52 patients (male: n = 35 (67%), female: n = 17 (33%)) at a median age of 62 years (35-73 years) underwent alloSCT after RIC. Conditioning was either total body irradiation (TBI)(2Gy)/±fludarabine (n = 33, 63.5%) or chemotherapy based. Graftversushost disease (GvHD) prophylaxis was carried out with cyclosporine A ± mycophenolate mofetil (MMF). 45 patients (87%) received shortcourse methotrexate (MTX). Mucositis was graded according to the Bearman and the World Health Organisation (WHO) scale. A variety of parameters were correlated with mucositis.

RESULTS

The Bearman and WHO scales showed excellent correlation. Mucositis was significantly more severe after chemotherapybased conditioning compared to conditioning with TBI(2Gy)/±fludarabine (p < 0.002) as well as in cases with an increase in creatinine levels above the upper normal value (UNV) on day +1 after SCT (p < 0.05). Furthermore, the severity correlated with time to engraftment of leucocytes (correlation coefficient (cc) = 0.26, p < 0.02) and thrombocytes (cc = 0.38, p < 0.001).

CONCLUSIONS

The conditioning regimen and increased creatinine levels at day +1 were identified as factors predicting the severity of mucositis after RICSCT. Creatinine levels on day +1 after SCT may help identify patients at risk for severe mucositis in the further course of transplantation.

[Allogeneic hematopoietic stem cell transplantation in elderly]

Most of patients with hematological malignancies are elderly (more than 60  years). Allogeneic stem cell transplantation is an important and effective treatment for most of these diseases. However, the toxicity and the supposed frailty of elderly patients, have limited the applicability of allogeneic transplantation for these patients. Elderly patients are at high risk to develop life-threatening complications, if allogeneic transplantation is performed with myeloablative conditioning regimens and using bone marrow stem source. Since more than 10 years, reduced intensity conditioning regimen have been developed, allowing to overcome the age as contra-indication for allogeneic transplantation. On the other hand, it is the presence of comorbidities which identify frail patients. For these subjects, allogeneic transplantation should be not indicated. Furthermore, advances in the supportive care and the development of new molecules could allow to reduce the toxicity of myeloablative conditioning regimens and thus to offer more intensive regimens before transplantation also in elderly population.

Radioimmunotherapy-based conditioning for hematopoietic cell transplantation in children with malignant and nonmalignant diseases

Targeted irradiation of the bone marrow with radiolabeled monoclonal antibodies (radioimmunotherapy) represents a novel therapeutic approach with both myeloablative and antileukemic potential. In an open-label, single-center pilot study, 30 pediatric and adolescent patients undergoing hematopoietic cell transplantation for malignant (n = 16) and nonmalignant (n = 14) disorders received treatment with a ⁹⁰Y-labeled anti-CD66 monoclonal antibody. Patients with a high risk of relapse (n = 7) received additional treatment with standard conditioning based on either total body irradiation or busulfan to intensify the antileukemic effect. In patients with comorbidities (n = 23), radioimmunotherapy was combined with a reduced-intensity conditioning regimen to reduce systemic toxicity. Preferential irradiation of the bone marrow was achieved in all patients. Nonrelapse mortality was 4 (13%) of 30 patients. In patients with malignant diseases, the probabilities of overall and disease-free survival at 2 years were 0.69 (95% confidence interval 0.37-0.87) and 0.46 (95% confidence interval 0.19-0.70), respectively. In patients with nonmalignant diseases, the probability of both overall and disease-free survival at 2 years was 0.94 (95% confidence interval 0.63-0.99). This pilot study demonstrates that radioimmunotherapy is effective in achieving myeloablation with low additional toxicity when used in combination with standard or reduced-intensity conditioning in young patients.

Retrospective analysis of common scoring systems and outcome in patients older than 60 years treated with reduced-intensity conditioning regimen and alloSCT

In this retrospective study, 63 patients >60 years with hematological malignancies and treated with allo-SCT and with reduced-intensity conditioning (RIC) were reviewed. A total of 51% of patients suffered from AML or myelodysplastic syndromes. Disease status before transplantation was CR or PR 71 with 29% transplanted with active disease. Patients were classified according to three published prognostic indexes: (1) hematopoietic cell transplantation comorbidity index (HCT-CI); (2) European BMT (EBMT) score; and (3) Pretransplantation Assessment of Mortality (PAM) score. The 100-day and 1-year treatment-related mortality (TRM) were 6 and 22%, respectively, for the entire group. The 2-year OS and PFS were 60 and 58%, respectively. The incidence of grade II-IV acute GVHD (aGVHD) and extensive chronic GVHD was 46 and 48%, respectively. In a univariate analysis, neither the HCT-CI nor the EBMT score, nor the PAM score were predictive of TRM and OS. Only the occurrence of aGVHD affected the TRM and OS. ALLO-RIC is feasible in elderly patients. Even if those prognostic scores were not adapted to elderly patients, they did not predict for TRM and OS. aGVHD is the main cause of TRM and more efforts should be made to reduce its incidence without sacrificing graft vs tumor effect.

Prognostic factor and quality of life analysis in 160 patients aged > or =60 years with hematologic neoplasias treated with allogeneic hematopoietic cell transplantation

Toxicity-reduced conditioning is a curative treatment option for medically compromised or elderly patients ineligible for myeloablative hematopoietic cell transplantation (HCT). The aim of this study was to detect prognostic factors for overall survival (OS) and to evaluate quality of life (QOL) in a large homogeneous cohort of 160 consecutive patients aged > or =60 years treated with allogeneic HCT. We evaluated age, sex, performance status, comorbidities, pulmonary function, lactic dehydrogenase concentration, type of donor, disease status, CD34(+) cells transplanted, cytomegalovirus status, time from diagnosis to HCT, and the development of acute and chronic graft-versus-host disease (GVHD). All patients who survived for > or =6 months (n = 79) were asked to complete a QOL survey. All patients (median age, 64.7 years; range, 60.1-76 years) received pretransplantation conditioning with fludarabine, BCNU, and melphalan. With a median follow-up of 35 months, the 1-year OS was 62.4% and 3-year OS was 47.4%. Multivariate analysis revealed compromised performance status as the most significant negative prognostic parameter for OS (P < .003), whereas male donor (P = .008) and chronic GVHD (P = .024) were associated with better OS. The 89% of survivors who returned the QOL questionnaire rated their global QOL as good-to-excellent despite impaired functional capabilities and such symptoms as fatigue, dyspnea, and loss of appetite. The main prognostic factor was performance status, not age. Our data suggest that toxicity-reduced conditioning offers a chance for enhanced OS with an adequate QOL.

Reduced-intensity conditioning hematopoietic stem cell transplantation in patients over 60 years: hematologic malignancy outcomes are not impaired in advanced age

Reduced-intensity-conditioning (RIC) hematopoietic stem cell transplantation (HSCT) is markedly underutilized in the elderly, in part because the impact of advanced age on outcomes is poorly understood. We retrospectively analyzed outcomes in 158 consecutive hematologic malignancy patients aged > or =60 years (median, 63 years; range: 60-71 years) undergoing fludarabine/busulfan-based RIC, with a median-follow-up of 34 months (range: 12.0-85.7). Multivariate analysis was undertaken for factors having an impact on outcome. For the patients aged > or =60 years, 2-year nonrelapse mortality (NRM) and relapse was 10% and 54.6%, respectively. Two-year overall and progression-free survival (OS, PFS) was 46% and 35%, respectively. Grade II-IV acute and chronic graft-versus-host disease (aGVHD, cGVHD) incidence was 19.6% and 45.9%, respectively. Comparing 110 patients aged 60-64 years versus 48 patients aged > or =65 years, 2-year NRM and relapse was 10.5% versus 8.3% (P = .84) and 53.5% versus 56.3% (P = .31), respectively. Grade II-IV aGVHD and cGVHD incidence was 19.1% versus 22.9% (P = .52) and 51.8% versus 32.5% (P = .01), respectively. Two-year OS and PFS was 49% versus 41% (P = .11) and 36% versus 35% (P = .24), respectively. In a multivariate Cox-model, high-risk disease associated with poorer PFS (hazard ratio [HR] = 2.1, P = .01) and OS (HR = 1.84, P = .03); acute myelogenous leukemia/myelodysplastic syndrome diagnosis (HR = 1.66, P = .03) and matched-related donor (HR = 1.62, P = .03) associated with poorer PFS. RIC HSCT is well tolerated, with reasonable survival in elderly patients. Age is not associated with impaired outcomes. HSCT should not be excluded solely based on advanced patient age.

Prospective phase II trial to evaluate the complications and kinetics of chimerism induction following allogeneic hematopoietic stem cell transplantation with fludarabine and busulfan

This prospective trial assessed the safety and efficacy of allogeneic hematopoietic stem cell transplantation from a HLA-matched donor with a reduced-intensity regimen (RIST) consisting of iv fludarabine 30 mg/m(2) for 6 days and oral busulfan 4 mg/kg/day for 2 days in patients older than 50 years with hematological malignancies. Cyclosporine alone or cyclosporine with short-term methotrexate was randomized for graft-versus-host disease prophylaxis. After 30 patients had been enrolled, an interim analysis was performed, and this report focuses on a precise evaluation of the toxicity profile and chimerism kinetics. Sustained engraftment in all patients, no severe regimen-related toxicity (RRT) within 20 days, and no transplant-related mortality through Day 100 were observed. T-cell (CD3+) full-donor (over 90%) chimerism was observed in 22 of the 30 patients, while the remaining eight had mixed-donor chimerism over 77% on Day 90. Thereafter, five subsequently converted to full-donor chimerism without donor lymphocyte infusion by day 120 (n = 4) or Day 180 (n = 1). Two showed persistent mixed chimerism without relapse through Day 180. Grade III-IV acute graft-versus-host disease and extensive chronic graft-versus-host disease occurred in 10% and 73%, respectively. With a median follow-up of 1.5 years, overall survival and disease-free survival at 1 year was 83% and 62%, respectively. Seven patients hematologically relapsed overall, and five of them had myelodysplastic syndrome with poor prognostic factors. In older patients, RIST with fludarabine and busulfan was associated with acceptable toxicities and a satisfactory antileukemia effect, regardless of the early chimerism status.

Nonmyeloablative allogeneic stem cell transplantation in elderly patients with hematological malignancies: results from the GITMO (Gruppo Italiano Trapianto Midollo Osseo) multicenter prospective clinical trial

This study aimed to evaluate the efficacy of a nonmyeloablative conditioning consisting of fludarabine and TBI in patients aged > or =60 years.A total of 32 patients (median age 62 years; range 60-70) with hematological malignancies were treated with fludarabine (30 mg/m(2) x 3-5 days) and 200 cCy TBI followed by allogeneic hematopoietic stem cell transplantation (HSCT) from a matched-sibling donor. GVHD prophylaxis consisted of cyclosporine and mycophenolate. Neutrophil recovery occurred in all patients at a median time of 16 days (range 9-34). Six patients did not become granulocytopenic. On day +30, 10 patients had >95% donor chimerism and 19 patients had mixed chimerism. The cumulative probabilities of Grade II-IV acute GVHD and chronic GVHD were 48 and 83%, respectively. Transplant-related mortality at 100 days and 1 year was 6 and 10%, respectively. The probabilities of 2-year overall (OS) and progression-free survival (PFS) were 39 and 35%, respectively. The estimated 2-year probability of OS and PFS for patients in early disease stages were 77 and 64%, respectively, which were significantly higher than the survival and PFS estimates of 0% obtained in patients with advanced disease stages at the time of transplant. Our analysis would suggest that for patients older than 60, this regimen is well tolerated and associated with a low incidence of transplant-related mortality. The leukemic burden at time of transplant has proven to be the most important risk factor for the outcome.

Allogeneic hematopoietic stem cell transplantation in the elderly

The development of reduced intensity or non-myeloablative conditioning (NST) in preparation for allogeneic stem cell transplantation (SCT) revolutionized the field and led to reconsideration of the dogma of upper age limit that was set up by the transplant centers as an eligibility parameter. Analysis of the literature data showed that NST regimens are associated with decreased transplant related mortality, and graft-versus-host disease, in comparison with standard myeloablative conditioning, in patients above the age of 50-55 years, or in younger patients with significant comorbidities. However we have to mention, that our considerations are based on the retrospective analysis of the literature data, and that well controlled prospective randomized studies are needed in order to definitely assess the role of NST. Comorbidity indices might be proved as the most important parameters for the choice of the most proper regimen for each patient in need and should be included in future trials.

Cardiac assessment of patients for haematopoietic stem cell transplantation

The expanding role of haematopoietic stem-cell transplantation (HSCT) renders the previous policy of avoiding transplantation in high-risk cardiac patients obsolete. Patients with amyloid, autoimmune conditions, sickle-cell disease, or thalassaemia, and patients over the age of 60 years are increasingly being offered HSCT. It is evident that the policy of avoiding transplantation in patients with impaired systolic function fails to identify all high-risk patients in such groups, and will deprive some patients of the benefits of HSCT unnecessarily. The development of an appropriate algorithm for cardiac pre-assessment and peri-transplant management is hampered by an inadequate understanding of the predictive value of various tests of cardiovascular function, the rapid evolution of advanced management strategies for cardiac dysfunction, and the development of non-cardiotoxic conditioning regimens. To meet this need we propose that an algorithm based on evidence from other clinical situations - already been found to be successful in the management of HSCT in patients with systemic sclerosis - should be used uniformly, and registry studies should be undertaken to distinguish those aspects of the algorithm that positively help to expand the remit of HSCT from those that add little of value.

Hematopoietic stem cell therapy for malignant diseases

Allogeneic bone marrow or blood stem cell transplantation (SCT) has changed its face in the last two decades. The introduction of nonmyeloablative conditioning regimens has reduced procedure toxicity and allowed the application of SCT in patients and conditions in which SCT was not offered in the past. In this review we will summarize the changes and accomplishments achieved in the past years in the field of stem cell transplantation for malignant disorders.

Hepatic Injury following Reduced Intensity Unrelated Cord Blood Transplantation for Adult Patients with Hematological Diseases

Liver injury is a common complication in allogeneic hematopoietic stem cell transplantation. Its major causes comprise graft-versus-host disease (GVHD), infection, and toxicities of preparative regimens and immunosuppressants; however, we have little information on liver injuries after reduced intensity cord blood transplantation (RICBT). We reviewed medical records of 104 recipients who underwent RICBT between March 2002 and May 2004 at Toranomon Hospital. Preparative regimen and GVHD prophylaxis comprised fludarabine/melphalan/total body irradiation and cyclosporine or tacrolimus. We assessed the etiology of liver injuries based on the clinical presentation, laboratory results, comorbid events, and imaging studies in 85 patients who achieved primary engraftment. The severity of liver dysfunction was assessed according to the National Cancer Institute Common Toxicity Criteria version 2.0. Hyperbilirubinemia was graded according to a report by Hogan et al (Blood. 2004;103:78-84). Moderate to very severe liver injuries were observed in 36 patients. Their causes included cholestatic liver disease (CLD) related to GVHD or sepsis (n = 15), GVHD (n = 7), cholangitis lenta (n = 5), and others (n = 9). Median onsets of CLD, GVHD, and cholangitis lenta were days 37, 40, and 22, respectively. Frequencies of grade 3-4 alanine aminotransferase elevation were comparable across the 3 types of hepatic injuries. Serum gamma-glutamil transpeptidase was not elevated in any patients with cholangitis lenta, whereas 27% and 40% of patients with CLD and GVHD, respectively, developed grade 3-4 gamma-glutamil transpeptidase elevation. Multivariate analysis identified 2 risk factors for hyperbilirubinemia; grade II-IV acute GVHD (relative risk, 2.23; 95% confidential interval, 1.11-4.47; P = .024) and blood stream infection (relative risk, 3.77; 95% confidential interval, 1.91-7.44; P = .00013). In conclusion, the present study has demonstrated that the hepatic injuries are significant problems after RICBT, and that GVHD and blood stream infection contribute to their pathogenesis.

Use of prophylactic anticoagulation and the risk of hepatic veno-occlusive disease in patients undergoing hematopoietic stem cell transplantation: a systematic review and meta-analysis

Hepatic veno-occlusive disease is a serious regimen-related toxicity in patients undergoing hematopoietic stem cell transplantation. We performed a systematic review and meta-analysis of the literature on the effect of anticoagulation in preventing veno-occlusive disease. Several databases and online journals were searched for randomized controlled trials and cohort studies. Twelve studies (2782 patients) were eligible. Anticoagulation prophylaxis was associated with a statistically nonsignificant decrease in risk of veno-occlusive disease (pooled relative risk (RR), 0.90; 95% confidence interval (CI), 0.62-1.29). Results of one of three randomized controlled trials may have been affected by delayed introduction of anticoagulation. A second trial enrolled patients who received conventional chemoradiotherapy for early-stage disease (RR, 0.18; 95% CI, 0.04-0.78). The third trial was a pilot study with a small sample size (RR, 0.74; 95% CI, 0.53-1.04). Significant heterogeneity and methodologic weaknesses preclude drawing a meaningful conclusion from the pooled analysis. Despite some limitations, results of two of three eligible randomized controlled trials suggest that prophylactic anticoagulation may help prevent veno-occlusive disease. However, a large randomized controlled trial is needed for confirmation. Additionally, in future studies, owing to the wide spectrum of severity of veno-occlusive disease, outcomes such as 100-day mortality should strongly be considered.

Myeloablative allogeneic hematopoietic stem cell transplantation in elderly patients

This study aimed to evaluate the outcome following myeloablative allogeneic hematopoietic stem cell transplantation (SCT) among patients older than 50 yr of age. A total of 215 patients with a median age of 57 yr underwent allogeneic hematopoietic SCT for early (41%) or advanced (59%) hematologic malignancies. After a median follow-up of 36 months a 10-yr survival estimate of 56 +/- 6% could be assessed for patients in early disease stages while patients with advanced diseases showed a significantly decreased survival probability of 31 +/- 5% (p < 0.0002). Transplant related mortality (TRM) at day 100 and 365 post-transplant was 13% and 30% for early but increased to 21% and 49% for advanced disease stages. As major determinants of TRM advanced disease stage (p < 0.0001) and occurrence of grades II-IV graft-vs.-host disease (GVHD) (p < 0.0001) were identified. These results show that hematopoietic SCT following myeloablative conditioning is also applicable to elderly patients whereas disease stage and high-grade GVHD represent the essential prognostic factors for outcome.

Nonmyeloablative Stem Cell Transplantation for Myelodysplastic Syndrome or Acute Myeloid Leukemia in Patients 60 Years or Older

We analyzed the outcomes of 24 consecutive patients aged >or=60 years with poor-prognosis myelodysplastic syndrome or acute myeloid leukemia undergoing transplantation with nonmyeloablative conditioning using fludarabine (125 mg/m2) and low-dose total body irradiation (2 Gy) followed by allogeneic peripheral blood stem cell grafts from HLA-identical sibling donors. Graft-versus-host disease (GVHD) prophylaxis consisted of cyclosporine and mycophenolate mofetil. The median age of the patients was 64 years (range, 60-71 years). In addition to age, 88% of patients had 1 or more adverse biological features of the disease. With a median follow-up of 21 months, 12 patients are alive, 11 of whom are disease free. The probabilities of 2-year overall and progression-free survival were 52% and 44%, respectively. The cumulative probabilities of relapse and of acute and chronic GVHD were 27%, 45%, and 74%, respectively. Nonrelapse mortality at 100 days and 2 years was 8% and 25%, respectively. Of the 15 patients with extensive chronic GVHD, 1 patient relapsed. These data suggest that nonmyeloablative stem cell transplantation is a feasible treatment option in patients aged >or=60 years with poor-prognosis myelodysplastic syndrome or acute myeloid leukemia. The reasonable disease control with nonmyeloablative transplantation in this high-risk group of patients merits further investigation.

Nonmyeloablative stem cell transplantation and cell therapy for malignant and non-malignant diseases

The conditioning prior to allogeneic stem cell transplantation was originally designed as a myeloablative conditioning, designed to eliminate malignant or genetically abnormal cells and then use the transplant procedure for rescue of the patients or to replace missing bone marrow products. However, allografts can induce effective graft vs. malignancy effects and can also eliminate undesirable hematopoietic stem cells in patients with genetic disorders and autoimmune diseases, thus documenting that alloreactive effects mediated by donor lymphocytes post-grafting can play a major role in eliminating hematopoietic cell of host origin, as well as provide effective immunotherapy for the treatment of disease recurrence. The efficacy of donor lymphocyte infusion (DLI) could be improved by activation with rIL-2 or by donor immunization. The cumulative experience over the years suggesting that alloreactive donor lymphocytes were most effective in eliminating tumor cells of host origin resulted in an attempt to reduce the intensity of the conditioning in preparation for the transplant procedure used for the treatment of hematological and other malignancies as well as life-threatening non-malignant disorders for which allogeneic stem cell transplantation may be indicated. Our working hypothesis proposed that the myeloablative conditioning which is hazardous and may be associated with early and late side effects, may not be required for treatment of patients with any indication for allogeneic stem cell transplantation. Instead, nonmyeloablative conditioning based on the use of reduced intensive preparatory regimen, also known as nonmyeloablative stem cell transplantation, may be sufficient for engraftment of donor stem cells while avoiding procedure-related toxicity and mortality, followed by elimination of undesirable cells of host origin by post-transplant effects mediated by alloreactive donor lymphocytes infused along with donor stem cells or administered subsequently as DLI. Improvement of the immediate outcome of stem cell transplantation using NST due to a significant decrease in transplant related mortality has broadened the spectrum of patients eligible for allogeneic stem cell transplantation, including elderly patients and other patients with less than optimal performance status. Likewise, the safer use of stem cell transplantation prompted expanding the scope of potential indications for allogeneic stem cell transplantation, such as metastatic solid tumors and autoimmune disorders, which now are slowly becoming much more acceptable. Current strategies focus on the need to improve the capacity of donor lymphocytes to eliminate undesirable malignant and non-malignant hematopoietic cells of host origin, replacing abnormal or malignant stem cells or their products with normal hematopoietic stem cells of donor origin, while minimizing procedure-related toxicity and mortality and improving the quality of life by reducing the incidence and severity of hazardous acute and chronic GVHD.

Ablative allogeneic hematopoietic cell transplantation in adults 60 years of age and older

PURPOSE

To evaluate outcomes of ablative allogeneic hematopoietic cell transplantation (HCT) in older patients with hematologic malignancies.

PATIENTS AND METHODS

We treated 52 patients from 1979 to 2002 with a median age of 62.8 years (range, 60.1 to 67.8 years) using ablative preparative regimens followed by allogeneic HCT from sibling donors. Diagnoses included myelodysplastic syndrome (MDS; n = 35), chronic myeloid leukemia (CML; n = 8), acute myeloid leukemia (AML; n = 6), and other (n = 3). Conditioning regimens included cyclophosphamide (CY) and busulfan (BU) (67%), total-body irradiation and CY (21%), BU-fludarabine (10%), and CY (2%).

RESULTS

Eighteen (35%) of 52 patients are alive at a median of 4.6 years (range, 0.8 to 9.1 years) after transplantation. Median overall survival (OS) and progression-free survival were 300 and 218 days, respectively. Three-year OS and relapse rates are estimated to be 34% and 24%, respectively. Nonrelapse mortality (NRM) rates at 100 days and 3 years are estimated to be 27% and 43%, respectively. Grade 3 to 4 acute graft-versus-host disease (GVHD) occurred in 20% of patients, and chronic extensive GVHD was described in 53% of patients. Fourteen (40%) of 35 patients with MDS are alive at a median of 2.8 years (range, 0.8 to 8.2 years). Four of six patients with CML in chronic or accelerated phase are alive at a median of 6.9 years (range, 4.1 to 9.1 years) after transplantation. None of the patients with AML, CML in blast crisis, or other diagnoses have survived. Patients who underwent transplantation after 1993 had improved survival.

CONCLUSION

These data suggest that allogeneic HCT is feasible in selected patients > or = 60 years of age, although novel methods to reduce NRM while maintaining efficacy are needed.