Central nervous system relapses after bone marrow transplantation for acute lymphoblastic leukemia in remission

Effects of isolated central nervous system involvement evaluated by multiparameter flow cytometry prior to allografting on outcomes of patients with acute lymphoblastic leukemia

Introduction

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains a major strategy to cure patients with acute lymphoblastic leukemia (ALL). The aim of this study was to evaluate whether isolated flow cytometry (FCM)-positive central nervous system (CNS) involvement before allo-HSCT is clinically significant.

Methods

The effects of isolated FCM-positive CNS involvement prior to transplantation on the outcomes of 1406 ALL patients with complete remission (CR) were retrospectively investigated.

Results

Patients were classified into isolated FCM-positive CNS involvement (n=31), cytology-positive CNS involvement (n = 43), and negative CNS involvement (n = 1332) groups. Among the three groups, the 5-year cumulative incidence of relapse (CIR) values were 42.3%, 48.8%, and 23.4%, respectively (P<0.001). The 5-year leukemia-free survival (LFS) values were 44.7%, 34.9%, and 60.8%, respectively (P<0.001). Compared with the negative CNS group (n=1332), the 5-year CIR of the pre-HSCT CNS involvement group (n=74) was higher (46.3% vs. 23.4%, P<0.001], and the 5-year LFS was inferior (39.1% vs. 60.8%, P<0.001). Multivariate analysis indicated that four variables, T-cell ALL, in second complete remission or beyond (CR2+) at HSCT, pre-HSCT measurable residual disease positivity, and pre-HSCT CNS involvement, were independently associated with a higher CIR and inferior LFS. A new scoring system was developed using the following four variables: low-risk, intermediate-risk, high-risk, and extremely high-risk groups. The 5-year CIR values were 16.9%, 27.8%, 50.9%, and 66.7%, respectively (P<0.001), while the 5-year LFS values were 67.6%, 56.9%, 31.0%, and 13.3%, respectively (P<0.001).

Conclusion

Our results suggest that ALL patients with isolated FCM-positive CNS involvement are at a higher risk of recurrence after transplantation. Patients with pre-HSCT CNS involvement had higher CIR and inferior survival outcomes.

ESTRO ACROP and SIOPE recommendations for myeloablative Total Body Irradiation in children

BACKGROUND AND PURPOSE

Myeloablative Total Body Irradiation (TBI) is an important modality in conditioning for allogeneic hematopoietic stem cell transplantation (HSCT), especially in children with high-risk acute lymphoblastic leukemia (ALL). TBI practices are heterogeneous and institution-specific. Since TBI is associated with multiple late adverse effects, recommendations may help to standardize practices and improve the outcome versus toxicity ratio for children.

MATERIAL AND METHODS

The European Society for Paediatric Oncology (SIOPE) Radiotherapy TBI Working Group together with ESTRO experts conducted a literature search and evaluation regarding myeloablative TBI techniques and toxicities in children. Findings were discussed in bimonthly virtual meetings and consensus recommendations were established.

RESULTS

Myeloablative TBI in HSCT conditioning is mostly performed for high-risk ALL patients or patients with recurring hematologic malignancies. TBI is discouraged in children <3-4 years old because of increased toxicity risk. Publications regarding TBI are mostly retrospective studies with level III-IV evidence. Preferential TBI dose in children is 12-14.4 Gy in 1.6-2 Gy fractions b.i.d. Dose reduction should be considered for the lungs to <8 Gy, for the kidneys to ≤10 Gy, and for the lenses to <12 Gy, for dose rates ≥6 cGy/min. Highly conformal techniques i.e. TomoTherapy and VMAT TBI or Total Marrow (and/or Lymphoid) Irradiation as implemented in several centers, improve dose homogeneity and organ sparing, and should be evaluated in studies.

CONCLUSIONS

These ESTRO ACROP SIOPE recommendations provide expert consensus for conventional and highly conformal myeloablative TBI in children, as well as a supporting literature overview of TBI techniques and toxicities.

Prognosis and risk factors for central nervous system relapse after allogeneic hematopoietic stem cell transplantation in acute myeloid leukemia

We performed a nested case-control study to investigate the incidence, treatment, and prognosis of central nervous system (CNS) relapse after allogenic hematopoietic stem cell transplantation (allo-HSCT) for acute myeloid leukemia (AML) and compared the outcomes of patients with CNS relapse following haploidentical donor (HID) HSCT versus identical sibling donor (ISD) HSCT. A total of 37 patients (HID-HSCT, 24; ISD-HSCT, 13) developed CNS relapse after transplantation between January 2009 and January 2019, with an incidence of 1.81%. The median time from transplantation to CNS relapse was 239 days. Pre-HSCT CNS involvement (HR 6.940, 95% CI 3.146-15.306, p < .001) was an independent risk factor for CNS relapse after allo-HSCT for AML. The 3-year overall survival (OS) for patients with CNS relapse was 60.3 ± 8.8%, which was significantly lower than that in the controls (81.5 ± 4.5%, p = .003). The incidence of CNS relapse was 1.64% for patients who received HID-HSCT and 2.55% for those who received ISD-HSCT (p = .193). There was no significant difference in OS between the HID-HSCT and ISD-HSCT subgroups among the patients with CNS relapse. In conclusion, CNS relapse is a rare but serious complication after allo-HSCT for AML, and the incidence and outcomes of patients with CNS relapse are comparable following HID-HSCT and ISD-HSCT.

Comparison of central nervous system relapse outcomes following haploidentical vs identical-sibling transplant for acute lymphoblastic leukemia

To explore the incidence, risk factors, and outcomes of central nervous system (CNS) relapse after allogeneic hematopoietic stem cell transplantation (allo-HSCT) for acute lymphoblastic leukemia (ALL) and to compare the differences in CNS relapse between haploidentical donor HSCT (HID-HSCT) and HLA-identical sibling donor HSCT (ISD-HSCT). We performed a retrospective nested case-control study on patients with CNS relapse after allo-HSCT. The cumulative incidence of CNS relapse was 4.06% after allo-HSCT in ALL, with a significantly poor prognosis. The incidence was 3.91% and 5.36% in HID-HSCT and ISD-HSCT, respectively (p = .227). Among the patients with CNS relapse, the overall survival (OS) at 3 years was 56.2 ± 6.8% in the HID-HSCT subgroup and 76.9 ± 10.2% in the ISD-HSCT subgroup (p = .176). The 3-year cumulative incidence of systemic relapse was also comparable between the two subgroups (HID-HSCT, 40.6 ± 7.4%; ISD-HSCT, 13.3 ± 8.7%, respectively, p = .085). Younger age (p = .045), T-ALL (p = .035), hyperleukocytosis at diagnosis (p < .001), advanced disease stage at transplant (p < .001), pre-HSCT CNS involvement (p < .001), and absence of chronic graft vs host disease (cGVHD) (p < .001) were independent risk factors for CNS relapse after allo-HSCT. In conclusion, CNS relapse was a significant complication after allo-HSCT in ALL and was associated with poor prognosis. The incidences and outcomes were comparable between HID-HSCT and ISD-HSCT.

[The efficacy analysis of allogeneic hematopoietic stem cell transplantation in 48 leukemia patients with central nervous system leukemia]

Objective: To investigate the efficacy of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in the treatment of leukemia patients also suffering from central nervous system leukemia (CNSL) . Methods: A total of 48 leukemia patients with central nervous system leukemia admitted to our hospital from May 2012 to December 2017 were retrospectively analyzed. Results: ① Including 22 cases of acute lymphocytic leukemia (ALL) , 21 cases of acute myeloid leukemia (AML) , and 5 cases of chronic myelogenous leukemia (CML) . Before transplantation, 19 patients achieved complete remission (CR) , and the rest 29 ones without remission. ②The conditioning regimen used TBI as the main protocol, and 6 patients were combined with whole brain and total spinal cord radiotherapy, 2 with Cyber knife treatment, and children with modified IDA combined with BUCY. ③All 48 patients were successfully transplanted, the median time for leukocyte engraftment was 14 (10-23) days, the median time for platelet transplant 16 (6-78) days. ④Bone marrow was evaluated 28 days after transplantation, all 48 patients reached CR, and DNA testing confirmed that they were all full donor chimerism. ⑤The median follow-up was 14 (2-69) months. Of them, 28 cases survived, 10 relapsed and the rest 3 had recurrence of CNSL after transplantation. One year after allo-HSCT, the overall survival (OS) of CR and non-CR groups were (77.3±10.0) % and (57.6±9.3) % (P=0.409) , respectively, the disease-free survival rates (DFS) were (71.2±11.0) % and (53.9±9.5) % (P=0.386) , respectively. The 1-year OS rates of ALL and AML groups after transplantation were (54.2±10.7) %, (80.1±8.9) %, respectively (P=0.200) , and DFS rates were (49.2±10.8) %, (75.0±9.7) % (P=0.190) , respectively. Conclusion: Allo-HSCT was safe and effective for leukemia patients with CNSL.

Augmenting Total Body Irradiation with a Cranial Boost before Stem Cell Transplantation Protects Against Post-Transplant Central Nervous System Relapse in Acute Lymphoblastic Leukemia

The purpose of this study was to determine the effect of a pretransplant cranial boost (CB) on post-transplant central nervous system (CNS) relapse and survival in acute lymphoblastic leukemia (ALL) patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT) using a total body irradiation (TBI)-containing preparation regimen. Two hundred thirteen ALL patients were treated consecutively at our institution with allogeneic HSCT. Conditioning included TBI (1320 cGy in 8 fractions given twice daily) and cyclophosphamide (120 mg/kg) with or without fludarabine (75 mg/m²). Patients were divided into 4 groups based on history of CNS disease and whether a CB was given. Of the 160 patients with no history of CNS disease, none received a CB (CNS-/CB-). Of the 53 patients with prior CNS disease, 41 had not received prior cranial irradiation. Thirty of these 41 received a CB of 900 to 1000 cGy in 5 daily fractions (CNS+/CB+), whereas the other 11 did not receive a CB because of physician preference (CNS+/CB-). The remaining 12 patients with prior CNS involvement had previously received cranial irradiation and thus were not candidates for a CB (CNS + PriorRT). Two-year CNS relapse risk, overall survival (OS), and disease-free survival (DFS) were calculated using Kaplan-Meier analysis. Seven patients experienced post-transplant CNS relapse: 4 in the CNS-/CB- group, 2 in the CNS+/CB- group, and 1 in the CNS + PriorRT group. None of the 30 patients who received a CB relapsed in the CNS. Two-year CNS relapse risk was 0% in the CNS+/CB+ group compared with 21% (95% CI, 0% to 45%) in the CNS+/CB- group (P = .03). Two-year OS and DFS did not differ between the groups. In conclusion, among ALL patients with prior CNS leukemia, there was a trend toward a reduced risk of post-transplant CNS relapse in patients who received a CB. However, the addition of a CB did not appear to have an impact on OS or DFS.

[Preventative and therapeutic relapse strategies after allogeneic hematopoietic stem cell transplantation: Guidelines from the Francophone society of bone marrow transplantation and cellular therapy (SFGM-TC)]

Disease relapse remains the first cause of mortality of hematological malignancies after allogeneic hematopoietic stem cell transplantation (allo-HCT). The risk of recurrence is elevated in patients with high-risk cytogenetic or molecular abnormalities, as well as when allo-HCT is performed in patients with refractory disease or with persistent molecular or radiological (PET-CT scan) residual disease. Within the frame of the 7th annual workshops of the francophone society for bone marrow transplantation and cellular therapy, the working group reviewed the literature in order to elaborate unified guidelines for the prevention and treatment of relapse after allo-HCT. For high risk AML and MDS, a post transplant maintenance strategy is possible, using hypomethylating agents or TKI anti-FLT3 when the target is present. For Philadelphia positive ALL, there was a consensus for the use of post-transplant TKI maintenance. For lymphomas, there are no strong data on the use of post-transplant maintenance, and hence a preemptive strategy is recommended based on modulation of immunosuppression, close follow-up of donor chimerism, and donor lymphocytes infusion. For multiple myeloma, even though the indication of allo-HCT is controversial, our recommendation is post transplant maintenance using bortezomib, due to its a good toxicity profile without increasing the risk of GVHD.

Low-dose cranial boost in high-risk adult acute lymphoblastic leukemia patients undergoing bone marrow transplant

PURPOSE

Acute lymphoblastic leukemia (ALL) has a predilection for CNS involvement. Patients with high-risk ALL are often managed with transplant using a radiation-based conditioning regimen. Historically, a high-dose prophylactic cranial boost (CB) of ≥12 Gy was given to reduce risk of central nervous system (CNS) recurrence. However, the use of CB has fallen out of favor because of toxicity concerns. In high-risk adults undergoing transplant at our institution, we have used a low-dose 6 Gy CB to reduce toxicity while conditioning adults with fully developed brains. The safety, efficacy, and utility of a low-dose CB in adults are poorly studied; herein, we report their outcomes and toxicity.

METHODS AND MATERIALS

We identified all high-risk ALL patients undergoing total body irradiation as part of their conditioning regimen. Those who received 6 Gy CB or no CB were included (55 total). Their charts were reviewed and statistical analyses were completed with R, version 2.15.2.

RESULTS

In patients undergoing CB, 3-year CNS disease-free survival and overall survival were 94.7% and 62.7%. In those not undergoing CBs, survivals were 81.8% and 51.5%. Notably, within the CB cohort, patients without prior CNS involvement had no CNS failures. In contrast, in the non-CB cohort, there were 2 CNS failures in patients with no history of CNS involvement. In the CB cohort, the only notable acute toxicity was parotitis (2.8%). Late toxicity in the CB cohort included 1 instance of cataracts (2.8%) without any evidence of cognitive impairment or potential radiation induced secondary malignancy.

CONCLUSIONS

A dose of 6 Gy CB is well-tolerated in the adult ALL population as part of a radiation-based conditioning regimen. Low-dose CB may be considered in adult patients with high-risk ALL without prior CNS involvement to reduce the likelihood of recurrence.

Efficacy of prophylactic additional cranial irradiation and intrathecal chemotherapy for the prevention of CNS relapse after allogeneic hematopoietic SCT for childhood ALL

We evaluated the efficacy of CRT and IT chemotherapy, in addition to conditioning including TBI, for the prevention of CNS relapse, in allogeneic HSCT for childhood ALL. From January 1999 to December 2009, a total of 48 patients, without previous or presenting CNS involvement, underwent HSCT for ALL. All patients received myeloablative conditioning including TBI of 12 or 13.2 Gy and IT chemotherapy twice between days -10 and -2 prior to HSCT. Twenty-five patients received CRT prior to TBI (CRT+), and 23 patients did not (CRT-). CRT+ and CRT- patients had a seven-yr EFS rate of 40.0 ± 9.8% and 41.7 ± 10.6%, respectively (p = 0.8252). The seven-yr relapse rates for CRT+ and CRT- patients were 45.0 ± 11.2% and 38.4 ± 11.6%, respectively (p = 0.7460). CNS relapses were evident in 1 (4.0%) CRT+ patient and 1 (4.4%) CRT- patient (p = 1.000). There were no significant differences in EFS and the probability of CNS relapse between CRT+ and CRT- patients. These results demonstrate that CRT and IT chemotherapy, in addition to conditioning chemotherapy, may not be necessary in childhood ALL patients without previous or presenting CNS involvement.

Central nervous system relapse in adults with acute lymphoblastic leukemia after allogeneic hematopoietic stem cell transplantation

Central nervous system (CNS) relapse after allogeneic hematopoietic stem cell transplantation (HSCT) confers a poor prognosis in adult patients with acute lymphoblastic leukemia (ALL). Preventing CNS relapse after HSCT remains a therapeutic challenge, and criteria for post-HSCT CNS prophylaxis have not been addressed. In a 3-center retrospective analysis, we reviewed the data for 457 adult patients with ALL who received a first allogeneic HSCT in first or second complete remission (CR). All patients received CNS prophylaxis as part of their upfront therapy for ALL, but post-transplantation CNS prophylaxis practice varied by institution and was administered to 48% of the patients. Eighteen patients (4%) developed CNS relapse after HSCT (isolated CNS relapse, n = 8; combined bone marrow and CNS relapse, n = 10). Patients with a previous history of CNS involvement with leukemia had a significantly higher rate for CNS relapse (P = .002), and pretransplantation CNS involvement was the only risk factor for post-transplantation CNS relapse found in this study. We failed to find a significant effect of post-transplantation CNS prophylaxis to prevent relapse after transplantation. Furthermore, no benefit for post-transplantation CNS prophylaxis could be detected when a subgroup analysis of patients with (P = .10) and without previous CNS involvement (P = .52) was performed. Finally, we could not find any significant effect for intensity of the transplantation conditioning regimen on CNS relapse after HSCT. In conclusion, CNS relapse is an uncommon event after HSCT for patients with ALL in CR1 or CR2, but with higher risk among patients with CNS involvement before transplantation. Furthermore, neither the use of post-HSCT CNS prophylaxis nor the intensity of the HSCT conditioning regimen made a significant difference in the rate of post-HSCT CNS relapse.

Allogeneic hematopoietic stem cell transplantation for ATL with central nervous system involvement: the Nagasaki transplant group experience

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is regarded as a curative option for aggressive adult T cell leukemia-lymphoma (ATL). However, the efficacy and safety of allo-HSCT for ATL with central nervous system (CNS) involvement, which is highly resistant to chemotherapy, remain controversial. We analyzed 10 ATL patients with CNS involvement who received allo-HSCT at three institutions in Nagasaki prefecture between 2000 and 2007. The 3-year overall survival rate was 40%, and the median observation time of the four surviving patients was 1532 days (range 945-2212 days). Two of four surviving patients received highly intensive local treatment for the CNS; one with 26 intrathecal injections of antineoplastic agents, and the other with whole cerebrospinal irradiation before transplantation. However, the other two patients received conventional or reduced-intensity conditioning with standard intrathecal chemotherapy. Three of the four surviving patients experienced chronic GVHD, and two of three patients with grade 3 or 4 acute GVHD were free from CNS relapse. From these data, it seems that both intensive local treatment for CNS disease and systemic GVHD contributed to the long-term control of CNS involvement. Although our data suggest that allo-HSCT is a therapeutic option for ATL with CNS disease, high transplant-related mortality (six cases) indicates the need for further studies to develop more effective procedures for CNS disease, and to reduce transplant-related morbidity.

Intrathecal chemoprophylaxis after HSCT in children

At present, the literature on the efficacy and risks of i.t. chemotherapy to children after HSCT is scarce. Current practices to reduce the risk of leukemic relapse in the CNS after HSCT differ between centers of transplantation. We compared 74 patients (56 ALL/18 AML), who received i.t. therapy post-HSCT with 46 patients (36 ALL/10 AML) who did not receive post-HSCT i.t. therapy. The patients were transplanted at the University Children's Hospital, Uppsala or the Karolinska University Hospital, Huddinge, two Swedish transplantation units with different routines concerning i.t. therapy after HSCT. The primary end-point was the number of isolated CNS relapses. Secondary end-points were other types of relapse, death, and neurological complications. There was no statistically significant difference in the incidence of CNS relapses between the groups (p > 0.05). I.t. therapy did not reduce the overall incidence of isolated CNS relapse or mortality. Our study did not demonstrate a protective effect of i.t. therapy indicating that post-HSCT i.t. therapy may only be of limited use in the treatment of acute childhood leukemia. We conclude that with the risks present, i.t. therapy should be carefully evaluated, and only considered in high-risk cases.

Allogeneic stem cell transplantation in children with acute lymphoblastic leukemia after isolated central nervous system relapse: our experiences and review of the literature

The prognosis of patients with acute lymphoblastic leukemia (ALL) and central nervous system (CNS) relapse has historically been very poor. Although chemo-radiotherapy has improved outcomes, some patients still have a poor prognosis after CNS relapse. Therefore, allogeneic hematopoietic stem cell transplantation (allo-SCT) has recently become an option for treatment of CNS leukemia; however, information, particularly on the long-term outcome of transplant recipients, is limited. We performed allo-SCT in eight pediatric patients with ALL (n=7) or T-cell type non-Hodgkin's lymphoma (n=1), who had isolated CNS relapse. All patients survived for a median of 70.5 (range, 13-153) months after SCT. Sequelae developed late in some patients: mental retardation (IQ=47) in one patient, severe alopecia in two patients, limited chronic graft-versus-host-disease in three patients, and amenorrhea and/or hypothyroidism in three patients. Except for a pre-school child with post transplant CNS relapse, six out of seven patients show normal school/social performance. Our results clearly indicate a high cure rate of isolated CNS relapse by allo-SCT in pediatric lymphoid malignancies; however, there needs to be further studies to determine which are the appropriate candidates for transplantation and what is the best transplant regimen to achieve high cure rate and maintain good quality of life.

Use of intrathecal prophylaxis in allogeneic haematopoietic stem cell transplantation for malignant blood diseases: a survey of the European Group for Blood and Marrow Transplantation (EBMT)

SUMMARY

A survey was carried out among EBMT centres to describe the current practice concerning intrathecal (i.t.) prophylaxis in allogeneic stem cell transplantation for malignant diseases in patients with no central nervous system (CNS) manifestations of the disease at any time. A total of 90 centres reported their practice: 42 centres (47%) never used pre-transplant i.t. prophylaxis as part of the conditioning, whereas 48 centres (53%) gave i.t. prophylaxis to selected groups. The main indications were acute lymphoblastic leukaemia (ALL), acute myeloid leukaemia (AML), and lymphoma (53, 33, and 23% of all centres, respectively). Prophylaxis was usually given to all patients with ALL, but often restricted to high-risk patients in AML and lymphoma. Of the 90 centres, 29 (32%) gave prophylactic i.t. treatment after the transplantation, mainly for the same indications as pre-transplant. This survey illustrates the heterogeneity in the current practice of i.t. prophylaxis in allogeneic transplantation for malignant blood disorders in Europe. The documentation in the literature to support the use of i.t. prophylaxis as part of transplantation for malignant diseases in patients without preceding CNS involvement is sparse. Based on the rarity of isolated CNS relapse after allogeneic stem cell transplantation, EBMT does not recommend routine i.t. prophylaxis to patients without prior CNS involvement.

Eye shielding during total body irradiation for bone marrow transplantation in children transplanted for a hematological disorder: risks and benefits

This is a retrospective analysis of 188 children who underwent total body irradiation (TBI) in one or two fractions before bone marrow transplantation (BMT) for a hematological disorder. While 139 children had eye shielding during TBI to decrease cataract formation, 49 did not. The blocks used for shielding caused cylindrical areas of decreased dose intensity in the brain. The aim of the study was to determine if there was an increased risk of relapse in the eyes or in the CNS after shielding of the eyes. The probability and severity of cataract formation with and without shielding were also evaluated. None of the 49 children without shielding had a relapse in their eyes or in the CNS after BMT. Of the children with shielding, none had a relapse in the eyes but two of the 139 (1.4%) had a CNS relapse. The incidence of cataracts without shielding was 90% (19 of 21 evaluable patients), while with shielding it was 31% (20 of 64). Severe cataracts were present in eight of 21 (38%) patients without and two of 64 (3%) patients with shielding. The probability of staying cataract free for at least five years was 0.77 with and 0.33 without shielding, at 8 years it was 0.53 and 0.24 respectively. The relative risk of developing a cataract without shielding vs shielding was three (95% CI=1.5; 5.9). It appears that the incidence of relapse in the eyes and CNS is not increased when the eyes are shielded during TBI. Shielding increased the latency time of cataract formation and decreased the severity of cataracts.

Total body irradiation-high-dose cytosine arabinoside and melphalan followed by allogeneic bone marrow transplantation from HLA-identical siblings in the treatment of children with acute lymphoblastic leukaemia after relapse while receiving chemotherapy: a Société Française de Greffe de Moelle study

We investigated the use of a new conditioning regimen followed by allogeneic bone marrow transplantation (BMT) for treating children with acute lymphoblastic leukaemia (ALL) after relapse within 6 months of the completion of therapy. One hundred and sixteen children with acute lymphoblastic leukaemia in second or subsequent complete remission (CR) underwent allogeneic bone marrow transplantation from HLA-identical siblings after a preparative regimen comprising total body irradiation (TBI), high-dose cytosine arabinoside and melphalan (TAM regimen). The Kaplan-Meier product-limit estimate (mean +/- SE) of disease-free survival (DFS) at 7 years was 59.5 +/- 9% (95% confidence interval). The estimated chance of relapse was 22.5 +/- 15% with a median follow-up of 88.5 months (range 51-132). 26 patients (22.4%) died with no evidence of recurrent leukaemia, mainly from interstitial pneumonitis, veno-occlusive disease or acute graft-versus-host disease (GVHD). Three factors significantly affected DFS: acute GVHD. site of relapse and, for children in second remission after a marrow relapse, the disease status at the time of transplantation. The DFS were 59.02 +/- 12.6%, 37.5 +/- 19.8% and 774 +/- 15% among patients in CR2 after a marrow relapse, in CR3 or in untreated partial marrow relapse, and in CR2 after an isolated CNS relapse, respectively. The lowest DFS was seen in children with acute GVHD grades 3-4. Two significant factors were associated with relapse: the marrow status at the time of transplantation and chronic GVHD. The relapse rate was lower among children in CR2 or with chronic GVHD. We conclude that transplantation after the TAM regimen is an effective therapy for this population with acceptable toxicity, particularly for children in second remission after a very early marrow relapse, or those with early isolated CNS involvement.

Meningeosis leukaemica in adult acute lymphoblastic leukaemia

This review addresses diagnosis of CNS involvement, incidence and treatment of CNS disease at time of diagnosis, prophylaxis and treatment of CNS relapse and risk factors for meningeal recurrence in adult acute lymphoblastic leukaemia (ALL). At the time of diagnosis meningeosis leukaemica is present in about 6% (1-10%) of the adult ALL patients with a higher incidence in ALL subgroups T-ALL (8%) and B-ALL (13 %). With the invention of early additional CNS directed therapy it no longer represents an unfavourable prognostic factor. In the absence of prophylaxis meningeal relapses occur in approximately one third of adults with ALL. A literature review including more than 4000 adult ALL patients showed for the different prophylactic treatment approaches the following CNS relapse rates: intrathecal therapy alone 13% (8-19%), intrathecal therapy and CNS irradiation 15% (6-22%), high dose chemotherapy 14% (10-16%), high dose chemotherapy and intrathecal therapy 8% (2-16%) and high dose chemotherapy, intrathecal therapy together with CNS irradiation 5% (1-12%). It became obvious that the early onset of intrathecal therapy and CNS irradiation and the continuation of intrathecal administrations throughout maintenance are essential. The most favourable results where achieved with high dose chemotherapy combined with intrathecal therapy and/or CNS irradiation. The majority of treatment regimens in adult ALL already include high dose chemotherapy in order to reduce the risk of bone marrow relapse. The outcome of patients with CNS relapse is still poor. Although a remission can be induced in the majority of patients (> 60%) it is usually followed by a bone marrow relapse and the survival is poor (< 5-10%). Bone marrow transplantation might be in adults at present the only curative approach.

Central nervous system relapse of lymphoid malignancies in adults: the role of high-dose chemotherapy

Adults with CNS recurrence of lymphoid malignancies generally have a very poor prognosis. Although recent reports indicate that a proportion of patients may obtain prolonged remission after bone marrow transplantation, the role of high-dose chemotherapy in the management of this complication remains controversial. We reviewed the literature in order to better evaluate the relative contribution of high-dose chemotherapy to the outcome of patients with CNS recurrence. We focused mainly on results in adults, but included results on pediatric patients when relevant. Our review of the data indicates that 20% to 40% of adults with a history of CNS involvement by lymphoma or lymphoid leukemia can be cured by high-dose chemotherapy. A small fraction of patients with active CNS involvement can be cured as well. No data is available to determine superiority of a particular conditioning regimen or of allogeneic vs. autologous BMT. There is no conclusive benefit to post-transplant intrathecal therapy and the role of cranial or cranio-spinal radiation treatment and its optimal timing remains to be determined. Prospective studies are needed to resolve many of the issues regarding the treatment, and to improve the outcome of patients with CNS recurrence of lymphoid malignancies.

Long-term results of autologous bone marrow transplantation in adult acute lymphoblastic leukemia

Autologous bone marrow transplantation (BMT) is widely performed in both adult and high-risk pediatric acute lymphoblastic leukemia (ALL). Nevertheless, there is still a lack of definitive data concerning its real effectiveness in prolonging the survival of these patients. Between 1984 and 1992, 20 ALL patients in first, second and third complete remission (CR) underwent autografting in the BMT Unit of the University of Milan. This series included 3 children in CR after one or more hematological relapses while all the other patients were adult. Autologous bone marrow was harvested during the same disease phase as that in which the autologous BMT was performed. The conditioning regimen included high-dose Ara-C, cyclophosphamide and TBI 1000 cGy. Successful engraftment occurred in all patients; no early deaths or deaths in CR were recorded, making disease-free survival and event-free survival (EFS) curves superimposable. The overall chance of EFS at 72 months was 41%: 57% for patients in first CR, 53% for patients autografted after one or more isolated meningeal relapse, 14% for patients autografted after one or more hematological relapse. The present data do not provide any evidence to support a role for autologous BMT in prolonging EFS in first CR ALL patients. Nevertheless, the results after meningeal relapse seem to be favourable when compared with the disappointing prospects of these patients after conventional chemotherapy. The EFS after hematological relapse revealed by this study does not significantly differ from that reported in the majority of other studies: the efficacy of autologous BMT in these ALL patients is doubtful.