Cynthia L. Toze

Lymphoproliferative disorders following allogeneic bone marrow transplantation : the Vancouver experience

Between June 1988 and May 1996, 428 patients underwent allogeneic BMT (288 related donor (RD) and 140 unrelated donor (UD)) at the Vancouver General Hospital. Eight patients (UD six and RD two) developed a post-transplant lymphoproliferative disorder (PTLD). Median age at BMT was 38 years (range 22–51). Five of the six UD allografts were T cell depleted. Cyclosporineu2009±u2009methotrexate was used for GVHD prophylaxis. All eight patients developed GVHD; in six this was refractory to treatment with corticosteroids. Rabbit antithymocyte globulin (ATG) or an anti-CD5-ricin A chain immunotoxin (Xomazyme) was used as second-line therapy for GVHD. Presentation with PTLD occurred at median day 90.5 (range 34–282) post BMT. Five of the eight patients had a rapidly progres- sive course characterized by fever, lymphadenopathy, lung and liver involvement and died within 3–8 days. PTLD was an incidental finding at post mortem examination in two patients. The remaining patient had localized disease and recovered. Pathological analysis revealed two morphological patterns; diffuse large B cell lymphoma (DLBC lymphoma, five patients) and polymorphous B cell hyperplasia (PBCH, three patients). EBV expression was positive in all eight cases and monoclonality was demonstrated in seven cases. In multivariate analysis, T cell depletion of the allograft (Pu2009=u20090.0001, relative risk (RR)u2009=u200930.5), anti-T cell therapy for GVHD (Pu2009=u20090.006, RRu2009=u200912.7) and acute GVHD grades 3–4 (Pu2009=u20090.04, RRu2009=u20097.7) were the significant factors for development of PTLD. In conclusion, we have identified two forms of PTLD after BMT: one is characterized by disseminated disease with a rapidly progres- sive and often fulminant course and the other by localized, relatively indolent disease. Morphology, EBV positivity and clonality do not appear to correlate with the clinical course. The major risk factors for development of PTLD after BMT are ex vivo T cell depletion of the allograft and in vivo anti-T cell therapy for GVHD.

Allogeneic bone marrow transplantation for low-grade lymphoma and chronic lymphocytic leukemia

Twenty-six patients with low-grade lymphoma (LGL) (nu2009=u200918) or chronic lymphocytic leukemia (CLL) (nu2009=u20098) received allogeneic BMTs between 1985 and 1998. Median age was 42 years, median interval from diagnosis to transplant 22u2009months and median number of prior treatments three. Twenty (77%) had stageu2009IV disease; 22 (85%) had never achieved CR. Donor source was HLA matched sibling (nu2009=u200919, 73%), matched unrelated (nu2009=u20096, 23%) or syngeneic (nu2009=u20091). Conditioning therapy included total body irradiation in 23 patients and busulphan in three. Twenty-five received GVHD prophylaxis with cyclosporine A; + methotrexate (nu2009=u200919), + methylprednisolone (nu2009=u20092) or + T cell depletion of allograftu2009±u2009methotrexate (nu2009=u20094). Sixteen patients are alive, a median of 2.4u2009years post BMT. Death occurred due to transplant complications (nu2009=u20097) or underlying disease (nu2009=u20093). Eighteen (12u2009LGL, six CLL) of 22 evaluable patients (82%) achieved CR post BMT. Cumulative incidence of refractory/recurrent disease was 18% (95% confidence interval (CI) 7–42%). Overall and event-free survivals were 58% (95% CI 35–75%) and 54% (95% CI 32–72%), respectively. Allogeneic BMT for young patients with advanced LGL or CLL is feasible and can result in long-term disease-free survival. Bone Marrow Transplantation (2000) 25, 605–612.

Myeloablative allografting for chronic lymphocytic leukemia : evidence for a potent graft-versus-leukemia effect associated with graft-versus-host disease

Summary:In all, 30 patients with CLL proceeded to myeloablative allogeneic BMT using related (n=20, 67%) or unrelated (n=10) donors, at the Princess Margaret Hospital (Toronto) (n=20) or the Leukemia/BMT Program of BC (Vancouver) (n=10), from 1989 to 2001. Median (range) interval from diagnosis to BMT was 4.8 (0.3–13) years, median number of prior therapies was three and median age 48 years. The preparative regimen included total body irradiation in 15 (50%). In all, 14 of 30 patients (47%) are alive, with median (range) follow up of 4.3 (2.4–10.5) years. All are in complete remission, two following therapy for post-BMT progression. Actuarial overall (OS) and event-free survival (EFS) at 5 years is 39% (OS 48% for related donor and 20% for unrelated donor BMT); cumulative incidence of nonrelapse mortality (NRM) and relapse is 47 and 19%, respectively. Both acute (RR=0.008, P=0.01) and chronic (RR=0.006, P=0.02) Graft-versus-host disease (GVHD) were associated with markedly decreased risk of relapse. Patients receiving grafts from unrelated donors had increased NRM (RR=3.6, P=0.02) and decreased OS (RR of death=3.4, P=0.002). Allogeneic BMT has resulted in long-term EFS in approximately 40% of patients with CLL. There is evidence for a strong graft-versus-leukemia effect associated with acute and chronic GVHD, resulting in near complete protection from relapse.

Stem cell transplantation for myelofibrosis: a report from two Canadian centers.

Summary:We describe the course of 25 patients with myelofibrosis (MF) due to agnogenic myeloid metaplasia (n=19) or essential thrombocytosis (n=6) who underwent allogeneic stem cell transplantation (SCT) at one of two Canadian centers. The median age at transplantation was 48.7 (IQR 45.9–50.4) years and transplantation was carried out at a median of 10.7 (IQR 5.67–26.5) months after diagnosis. Granulocyte engraftment (absolute neutrophil count >0.5 × 109/l) occurred at a median of 20 days after transplantation for splenectomized patients, compared with 27.5 days for nonsplenectomized individuals (P=0.03). Increased risk of grade II–IV acute graft-versus-host disease (P=0.04) was noted in patients transplanted after splenectomy. Patients with MF received 0.264±0.189u2009U of packed red blood cells per day over the first 180 days after transplantation, and remained dependent on red blood cell transfusions for a median of 123 (IQR 48–205) days. Complete remission of MF was documented in 33% of evaluable patients. The 1 year cumulative nonrelapse mortality was 48.3%. Median survival for this group of patients was 393 (IQR 109–1014+) days, with a projected 2-year overall survival of 41%. We conclude that allogeneic SCT offers a reasonable chance for prolonged survival in patients with advanced MF, but this occurs at the cost of considerable toxicity and nonrelapse mortality.

Treatment of Steroid-Resistant Acute Graft-Versus-Host Disease with Rabbit Antithymocyte Globulin

Acute graft-versus-host disease (A-GVHD) is a life-threatening complication of allogeneic stem cell transplantation (SCT), and primary therapy consists of high-dose corticosteroids. Patients who fail to respond adequately to corticosteroids require salvage treatment, with anti-T cell antibodies being the most commonly utilized group of agents. We report our institutions experience treating steroid-resistant GVHD in 36 adult patients (median age 39 years, range 24-55) with a rabbit antithymocyte globulin product (thymoglobulin). Eleven patients had undergone sibling SCT (10 histocompatible, 1 one-antigen mismatched) and 25 patients had received unrelated donor bone marrow (17 matched, 8 one-antigen mismatched); 32 patients (89%) had grade III or IV A-GVHD. Thymoglobulin was administered in two different regimens; group 1 patients (n = 13) received 2.5 mg/kg/day x 4-6 consecutive days with maintenance of all other immunosuppressives. Group 2 patients (n = 21) were given the same dose of thymoglobulin on days 1, 3, 5, and 7 with discontinuation of cyclosporine for 14 days, during which the corticosteroid dose was held at 2-3 mg/kg/day. Two patients had severe adverse reactions to thymoglobulin (hypoxemia and hypotension) and could not complete treatment, however, in the other patients, aside from transient leukopenia (25%) and and hepatic dysfunction (25%), the antibody preparation was well tolerated. Of the 34 evaluable patients, 13 patients had a complete response (38%) and 7 patients (21%) had a partial response, for an overall response rate of 59%. Response rate was higher in group 1 patients (77%) compared to group 2 patients (48%), (p = 0.15); skin GVHD was more responsive (96% of patients) than gut GVHD (46% of patients) or hepatic GHVD (36% of patients). Opportunistic infections were a significant complication, with 11 patients developing systemic fungal infections and 9 patients serious viral infections; there were seven episodes of bacteremia following thymoglobulin treatment and one fatal protozoal infection. There were 9 patients (25%) who developed post-SCT lymphoproliferative disorder (PTLD) and 4 patients who had a relapse of underlying primary malignancy; none of these patients survived. Of the 36 patients entered on the study, only 2 patients (6%) survive, at 15+ and 34+ months post-unrelated donor SCT. Although thymoglobulin is associated with an impressive response rate when administered for advanced steroid-resistant GVHD, long-term survival is uncommon, even in responders, primarily due to the high risk of developing either an opportunistic infection or a PTLD.

High incidence of extramedullary relapse of AML after busulfan/cyclophosphamide conditioning and allogeneic stem cell transplantation

While allogeneic stem cell transplantation (SCT) is curative for a significant number of patients with AML, relapse of disease within the bone marrow and/or extramedullary (EM) sites following high-dose therapy continues to limit the success of this treatment. Between October 1985 and December 1996, 81 adults underwent allogeneic SCT for de novo AML at our centre. Forty-two patients remain alive and free of leukaemia with a median follow-up of 50 months. The 5-year actuarial event-free survivals (EFS) for all patients and for those undergoing SCT in CR1 or with advanced disease were 46% (95% confidence interval (CI) 34–58%), 63% (CI 46–76%), and 19% (CI 7–36%), respectively. Twenty-two patients relapsed at a median of 8 (range 1.6–54.5) months with the actuarial risk of relapse for all, CR1 and advanced disease patients being 38%, (CI 27–52%), 23% (CI 13–40%) and 68% (CI 46–88%), respectively. Ten patients relapsed at EM sites; six of these (27% of relapses) had an isolated EM relapse at a median of 31 (range 8.5–54) months. Three of the patients with isolated EM relapse survived ⩾24 months following relapse and two patients remain disease-free at 29+ and 33+ months. BuCy conditioning followed by allogeneic SCT in AML results in satisfactory EFS although there is a significant risk of late isolated EM relapse.

Second malignancy following high-dose therapy and autologous stem cell transplantation: incidence and risk factor analysis

Summary:To establish incidence and risk factors for development of second malignant neoplasms after high-dose chemo/radiotherapy (HDT) and autologous hematopoietic stem cell transplantation (AHSCT), the case files of 800 consecutive patients who underwent AHSCT at our institution between June 1982 and December 2000 were reviewed. In all, 26 patients developed 29 second malignancies (nine myelodysplastic syndrome (MDS)/acute myelogenous leukemia (AML), 16 solid tumors and four lymphoproliferative disorders (LPDs)) for a 15-year cumulative incidence of 11% (95% confidence interval (CI), 5–18%). These second tumors occurred at a median of 68 (range 1.5–177) months following AHSCT. The relative risk (RR) compared to the general population of developing a second malignancy following AHSCT was 3.3 (CI 2.2–4.7) P<0.001. The RR of developing MDS/AML, LPD and a solid tumor was 47.2 (CI 21.5–89.5) P<0.001, 8.1 (2.2–20.7) P=0.002 and 1.98 (1.1–3.2) P=0.009, respectively. In multivariate analysis, age ⩾35 years at the time of AHSCT (P=0.001) and an interval from diagnosis to AHSCT ⩾36 months (P=0.03) were associated with a greater risk of developing a second malignancy. Patients who have undergone HDT and AHSCT are at significant risk for developing a second malignancy and should receive indefinite follow-up.

Allogeneic SCT for relapsed composite and transformed lymphoma using related and unrelated donors: long-term results

Outcome is poor with conventional therapy for relapsed transformed non-Hodgkins lymphoma (NHL). Autologous SCT has been successfully employed; however the impact of allogeneic SCT has not been well defined. We therefore studied 40 consecutive patients who received allogeneic SCT for relapsed composite and transformed NHL (25 transformed, 8 composite (same site) and 7 discordant (different sites)) with related (n=25) and unrelated donors (n=15) to evaluate long-term outcome. Conditioning was myeloablative in the majority (39 of 40). Of 40 patients, 11 survive with median follow-up of 25 months. Death occurred in similar proportions due to relapsed NHL (n=14) or treatment-related complications (transplant-related mortality, TRM; n=15). The cumulative incidence of TRM was 36% at 3 years and disease relapse was 42% at 5 years. Probability of 2- and 5-year event-free survival is 36 and 23% with overall survival 39 and 23%. Performance of SCT within 1 year of NHL diagnosis predicted improved outcome. Relapse and TRM remain significant problems in this setting, indicating the need for strategies whereby patients at high risk of transformation should be selected for early SCT, ideally before their actual transformation.

Characteristics and outcome of patients developing endocarditis following hematopoietic stem cell transplantation.

Summary:Endocarditis is an uncommon complication of hematopoietic stem cell transplantation (HSCT). A retrospective review of 1547 patients who underwent HSCT in Vancouver between January 1986 and December 2001 was performed. In all, 20 cases of endocarditis were identified (1.3% of all patients) with nine patients having received cryopreserved autologous stem cells, six stem cells from a histocompatible sibling and five patients stem cells from an unrelated donor. Five patients had endocarditis diagnosed while alive, a median of 6 months post-HSCT, by transthoracic (four patients) or transesophageal (one patient) echocardiography. The remaining 15 cases of endocarditis were only identified post mortem. The mitral valve was the most frequently involved (10 patients) followed by the aortic valve (six patients); multivalvular disease was noted in five patients. Of the 11 affected allogeneic HSCT patients, 10 had previously developed acute graft-versus-host disease (GVHD). Causative organisms were identified in 11 patients, while nine additional cases were felt to be thrombotic in origin. Of the 20 patients, 19 died with the sole survivor alive 10 years following an aortic valve replacement. Endocarditis is an uncommon complication of HSCT usually involving the cardiac valves on the left side of the heart and is associated with a high mortality rate.

Predictors of outcome following myeloablative allo-SCT for therapy-related myelodysplastic syndrome and AML

Administration of alkylating agents (Alk), topoisomerase II inhibitors (Topo II) and radiotherapy (RT) can result in therapy-related myelodysplastic syndrome or acute myelogenous leukaemia (t-MDS/t-AML), the optimal treatment for which is allo-SCT. A retrospective review was performed of 24 patients who underwent related- or unrelated-donor SCT for t-MDS/t-AML at our institution. Eight patients remain alive and in continuous remission (median follow-up 54 months (range, 12–161)) with estimated 5-year EFS being 30% (95% confidence intervals 16–58%). Corresponding actuarial risks of relapse and non-relapse mortality (NRM) are 39% (19–60%) and 30% (13–50%), respectively. EFS was 40% in Alk/RT-related t-MDS/t-AML and 11% in Topo II-related t-MDS/t-AML (P=0.05), with an increased risk of relapse in the latter (56 vs 29%, respectively (P=0.05)). In multivariate analysis, development of acute GVHD (P=0.009) and Topo II-related t-MDS/t-AML (P=0.018) were associated with inferior EFS. Patients with acute GVHD had an increased risk of NRM (P=0.03) whereas risk of relapse was higher for patients of advanced age (P=0.046) and for patients who underwent bone marrow (vs blood) SCT (P=0.032). Allo-SCT can result in long-term survival for individuals with t-MDS/t-AML although outcome in Topo II-related t-MDS/t-AML patients remains suboptimal.