Materials and methods

Patients who received HSCT for atypical CML, CMML and idiopathic myelofibrosis were selected for this analysis. All patients signed informed consent. The study including the retrospective chart review process was approved by the Institutional Review Board. In all, 20 consecutive patients who received a transplant for the above-mentioned diagnoses were identified from the Department of Blood and Marrow Transplant database. Their diagnosis was confirmed or made at MD Anderson Cancer Center. Atypical CML was diagnosed when patients presented with features of classical CML but their bone marrow cytogenetic studies did not show t(9;22) (Ph chromosome) and no BCR-ABL fusion gene was detected either by Southern blot analysis, by BCR gene probe or by RT-PCR. CMML was diagnosed when patients presented with monocytosis (absolute monocyte count >1 10⁹/l) associated with other myeloproliferative or myelodysplastic features like bone marrow dysplasia, leucocytosis, excess number of blasts in bone marrow or peripheral blood, anemia and splenomegaly. Idiopathic myelofibrosis was diagnosed in patients when bone marrow examination showed the presence of fibrosis, associated with other typical features like cytopenias and splenomegaly, in the absence of any other primary disease, which could cause such changes. Patients who were initially diagnosed as Ph chromosome-negative, BCR-ABL unknown CML, but later found to have BCR-ABL translocation, were excluded. Patients who had or developed >30% blasts prior to transplant were also excluded. All but one patient were treated with various chemotherapy regimens by their local oncologists or at MD Anderson Cancer Center prior to transplant.

HLA typing

HLA typing for class I antigens was performed using standard serological techniques, but after February 2001, high-resolution typing with sequencing for HLA-A and HLA-B was added to the routine typing (inconclusive results for HLA-C were resolved by molecular typing). Low-resolution molecular typing using hybridization techniques of amplified sampled DNA with sequence-specific oligonucleotide probes (SSOP), followed by high-resolution molecular typing using the method of polymerase chain reaction (PCR) in the sampled DNA with sequence-specific primers (SSP) was performed for class II antigens. Major mismatches were mismatches at the low-resolution level taking into account the serologic specificity of the HLA molecules. Minor mismatches were mismatches at the high-resolution level.

Conditioning regimens

Six patients received cyclophosphamide 60 mg/kg/day for 2 days plus intravenous busulfan 3.2 mg/kg/day for 4 days. Three patients received total body radiation (TBI) (12 Gy in divided fractions) plus cyclophosphamide (60 mg/kg/day for 2 days) plus etoposide 1500 mg/m² over 1 day (n=2) or etoposide 750 mg/m² over 3 days (n=1). Two other patients received same doses of TBI plus cyclophosphamide in addition to thiotepa 5 mg/kg over 1 day (n=1) or thiotepa 10 mg/kg over 1 day plus anti-thymocyte globulin (ATG) 15 mg/kg for 2 days (n=1). Two patients received fludarabine 30 mg/kg/day for 4 days plus cytarabine 500 mg/m²/day for 4 days plus melphalan 140 mg/m² for 1 day plus ATG 15 mg/kg/day for 2 days. Four patients received fludarabine 25 mg/m²/day for 5 days plus melphalan 90 mg/m²/day for 2 days including ATG 30 mg/m²/day for 3 days in two cases. Two patients received fludarabine 30 mg/m²/day for 4 days plus idarubicin 12 mg/m²/day for 3 days and cytarabine 2 g/m²/day for 4 days. One patient received fludarabine 30 mg/m²/day for 4 days plus intravenous busulfan 11.2 mg/kg (total dose) over 4 days.

Graft-versus-host disease prophylaxis

In all, 16 patients received graft-versus-host disease (GVHD) prophylaxis with tacrolimus in combination with methotrexate. Tacrolimus was administered daily from day -2 as a continuous intravenous infusion at 0.03 mg/kg, switched to oral administration as soon as oral intake was feasible. Doses were adjusted to maintain whole blood trough levels at 5–15 ng/ml. Methotrexate was given on days 1, 3, 6 and 11 at 5 mg/m². Tacrolimus was continued for 6–8 months post transplant. Four patients received cyclosporine in combination with either methotrexate (n=2) or steroids (n=2).

Supportive care

Patients were managed in reverse isolation in conventional or laminar airflow rooms. Infection prophylaxis during the peritransplantation period included trimethoprim–sulfamethoxazole for Pneumocystis carinii infection, fluconazole and/or inhaled amphotericin-B for antifungal prophylaxis, acyclovir for antiviral prophylaxis and an oral quinolone with or without penicillin for antibacterial prophylaxis. Cytomegalovirus (CMV) prophylaxis consisted of weekly or biweekly surveillance CMV cultures of blood using shell vial or rapid antigen techniques. Ganciclovir therapy was instituted if there was evidence of CMV antigenemia. Filgrastim 5 g/kg subcutaneously was given daily beginning on post transplant day 7 until the absolute neutrophil count (ANC) was 1500/mm³ for 3 consecutive days. All blood products were filtered and irradiated prior to transfusion.

Assessment of outcome

Day 0 was the stem cell infusion day. Time for neutrophil engraftment was calculated from day 0 until the first of 3 consecutive days when the ANC was 0.5 10⁹/l. Time for platelet engraftment was calculated from day 0 until the first of 7 consecutive days when the platelet count was 20 10⁹/l without transfusion support. Hematopoietic chimerism was evaluated on bone marrow cells by restriction fragment length polymorphisms (RFLP), fluorescent in situ hybridization studies in sex-mismatched cases for Y chromosome or by DNA microsatellite repeats polymorphism using PCR and gene scan. Toxicity was graded according to the criteria laid by Bearman et al,¹¹ and GVHD was graded according to consensus criteria.¹² Remission was determined by engraftment, less than <5% blasts in the bone marrow, absence of peripheral blood blasts and other disease features. Relapse was defined by standard morphologic criteria, conventional cytogenetic analysis, or both.

Analysis

Overall survival (OS), disease-free survival (DFS) and the actuarial incidence of acute GVHD were estimated using the Kaplan–Meier method.¹³ The cumulative incidence of chronic GVHD was estimated based on the method of Prentice and Kalbfleisch,¹⁴ considering death or relapse without chronic GVHD as competing risks.

Results

Patients

In all, 20 patients (15 male and five female patients) with a median age of 51 years (range 20–64 years) underwent HSCT for myelofibrosis (n=5), CMML (n=8) and atypical CML (n=7) between 1991 and 2001 (Tables 1 and 2). A total of 15 patients presented with splenomegaly. Six patients had abnormal cytogenetics including 46XY, t(1;15); 46XX, inv11; 47XXX, i17q; 47XX(+21); 46XY, del(13) and 47XY, (+8). In one patient, cytogenetics studies were not known. Seven patients underwent splenectomy prior to HSCT. Patients were treated with one (n=8), two (n=8), three (n=2), four (n=1) or no (n=1) chemotherapy regimens prior to transplant. Median time from diagnosis to transplant was 10 months (range 2–109 months).

Table 1 - Patient characteristics.

Full table

Table 2 - Individual patients characteristics and outcome.

Full table

Donors/HLA typing

A total of 15 patients received a transplant from related donors. Two of them had one class-I antigen mismatch with the donors. Five patients received unrelated donor transplant including one patient–donor pair with HLA-DR micromismatch. Six patients (male: 4; female: 2) received a transplant from female donors and 14 patients (male: 11; female: 3) received a transplant from male donors. Seven patients received sex-mismatched transplants.

Engraftment

The source of stem cells was unmodified bone marrow (n=10) or peripheral blood stem cells (n=9) and CD3+ depleted bone marrow in one patient. The median dose of total nucleated cells infused was 4.5 10⁸ (range 0.59–115.8 10⁸) cells/kg of recipient weight. The median dose of CD34+ cells infused was 4.7 10⁶ (range 1.14–7.15 10⁶) cells/kg of recipient weight. All patients had neutrophil recovery at a median time of 12 days (range 10–56 days), but the patient who recovered neutrophils at 56 days had engraftment failure with autologous reconstitution. In all, 15 patients had platelet recovery at a median time of 17 days (range 0–90 days); 18 patients achieved 100% donor chimerism while one patient had 90% donor chimerism at the time of recovery. All five patients with myelofibrosis had neutrophil recovery and achieved 100% donor chimerism. All of them recovered platelets (20 10⁹/l). One of them had platelet recovery at day 76 after transplant. All of them also achieved a platelet count 50 10⁹/l except one patient who died on day 68 due to treatment-related toxicity.

Treatment-related mortality and toxicity

Two patients developed Bearman grade 3 toxicity including liver dysfunction with ascites and hemorrhagic cystitis. One patient died on day 68 after transplant due to Bearman grade 4 toxicity including acute renal failure, sepsis and acute GVHD. Another patient died on day 103 due to GVHD and pancytopenia.

GVHD

Actuarial incidence of grade 2–4 acute GVHD was 45% (n=9) (95% CI 26–69%). Cumulative incidence of chronic GVHD (n=12, limited 6, extensive 6) was 60% (95% CI 37–85%).

Survival

After a median follow-up of 17.5 months (range 2.7–50.6 months), OS was 35% (95% CI 15–56%) and DFS was 31% (95% CI 12–52%) (Figure 1). A total of 12 patients died due to relapse (n=5), infection (n=3), chronic GVHD (n=2), acute GVHD and regimen-related toxicity (n=1) and unknown cause for one patient.

Figure 1.

Overall survival.

Full figure and legend (16K)

There was no difference in survival among patients who received bone marrow or peripheral blood stem cells (actuarial survival was 36% for both groups). Among 18 patients who survived beyond 100 days, 12 developed chronic GVHD. Eight of these patients are alive with a median survival of 33 months since transplant (range 11–51 months). GVHD was the cause of death for two patients, one patient died of sepsis, and the cause of death could not be ascertained for one patient. All remaining six patients who did not develop CGVH died of disease progression (n=5) or pneumonia (n=1).

Discussion

Allogeneic HSCT can induce long-term remissions in patients with MPD. A total of 20 patients with diagnoses of CMML, myelofibrosis or atypical CML received allogeneic HSCT. In this small cohort, heterogeneity of conditioning regimens and the use of related and unrelated donors limited our ability to perform a conclusive evaluation of prognostic factors.

The median survival of patients with myelofibrosis can range from 13 to 93 months.^15,16 Many case studies have been published showing the benefit of allogeneic transplant in myelofibrosis. Przepiorka et al⁵ reviewed 40 cases of MPD including myelofibrosis, hypereosinophilic syndrome and polycythemia vera treated with HLA-identical allogeneic transplant. Three-year survival was 55% (95% CI 44–76%). In another case series published by Anderson et al,⁶ 13 patients underwent allogeneic transplant for myelofibrosis, including three from unrelated donors. The two-year actuarial survival was 77%. Some initial case reports have shown delayed hematopoietic recovery after HSCT for myelofibrosis^7,17,18 but this has been challenged by other investigators.^5,10,19 In our study, we did not find any evidence of increased rates of graft failure or delayed engraftment in these patients. CMML is considered a hybrid disorder with features of both MDS and MPD with median survival of several months to years depending on prognostic features.^20,21 It has a high rate of transformation to acute leukemia and no significant improvement in disease course with chemotherapy.^21,22,23,24 Zang et al published a case series of 21 patients with CMML. In all, 12 patients received transplants from HLA-matched sibling, three from HLA nonidentical related donor and six patients received unrelated donor transplants. All patients received myeloablative conditioning regimens. The relapse-free survival at 3 years was estimated to be 39%. Patients who were transplanted early (disease duration <12 months) had better survival as compared to those who were transplanted later (disease duration 12 months).²⁵ We could not confirm this observation in our data set. There is extensive documentation of the curative effect of allogeneic HSCT in CML.²⁶ However, there are no reports in the literature investigating the role of HSCT in the treatment of atypical CML. Allogeneic transplant would appear to have the potential to improve long-term survival in these patients as well.

Nonmyeloablative transplants depend upon the graft-versus-tumor effect mediated by donor immunocompetent cells. The major advantage of this approach is a reduction in treatment-related toxicity, thus expanding the eligibility criteria to those patients who are otherwise not suitable candidates for transplant either because of age or other medical comorbidities.^27,28 Accordingly, Devine et al²⁹ and Hessling et al⁴ reported good results with dose-reduced regimens and allogeneic transplant for a total of seven patients with myelofibrosis and myeloid metaplasia. Considering that the median age of patients with these disorders is greater than 60 years, this approach is promising and may allow the use of allogeneic HSCT as a therapeutic option.

References

1. Harris NL, Jaffe ES, Diebold J et al. World Health Organization classication of neoplastic diseases of the hematopoietic and lymphoid tissues: report of the clinical advisory committee meeting – Airlie house, Virginia, November 1997. J Clin Oncol 1999; 17: 3835–3849. | PubMed | ISI | ChemPort |
2. Montefusco E, Alimena G, Coco L et al. Ph-negative and bcr-negative atypical chronic myelogenous leukemia: biological features and clinical outcome. Ann Hematol 1992; 65: 17–21. | Article | PubMed | ISI | ChemPort |
3. Kantarjian HM, Kurzrock R, Talpaz M. Philadelphia chromosome-negative chronic myelogenous leukemia and chronic myelomonocytic leukemia. Hematol/Oncol Clin N Am 1990; 4: 389–404.
4. Hessling J, Kroger, Werner M et al. Dose-reduced conditioning regimen followed by allogeneic stem cell transplantation in patients with myelofibrosis with myeloid metaplasia. Br J Haematol 2002; 119: 769–772. | Article | PubMed | ISI |
5. Przepiorka D, Giralt S, Khouri I et al. Allogeneic marrow transplantation for myeloproliferative disorders other than chronic myelogenous leukemia: review of forty cases. Am J Hematol 1998; 57: 24–28. | Article | PubMed | ISI | ChemPort |
6. Anderson JE, Sale G, Appelbaum FR et al. Allogeneic marrow transplantation for primary myelofibrosis secondary to polycythaemia vera or essential thrombocytosis. Br J Haematol 1997; 98: 1010–1016. | Article | PubMed | ISI | ChemPort |
7. Singhal S, Powles R, Treleaven J et al. Allogeneic bone marrow transplantation for primary myelofibrosis. Bone Marrow Transplant 1995; 16: 743–746. | PubMed | ISI | ChemPort |
8. Anderson JE, Appelbaum FR, Schoch G et al. Allogeneic marrow transplantation for myelodysplastic syndrome with advanced disease morphology: a phase II study of busulfan, cyclophosphamide, and total-body irradiation and analysis of prognostic factors. J Clin Oncol 1996; 14: 220–226. | PubMed | ISI | ChemPort |
9. O'Donnell MR, Nademanee AP, Snyder DS et al. Bone marrow transplantation for myelodysplastic and myeloproliferative syndromes. J Clin Oncol 1987; 5: 1822–1826. | PubMed | ChemPort |
10. Guardiola P, Esperou H, Cazals-Hatem D et al. Allogeneic bone marrow transplantation for agnogenic myeloid metaplasia. Br J Haematol 1997; 98: 1004–1009. | Article | PubMed | ISI | ChemPort |
11. Bearman SI, Appelbaum FR, Buckner CD et al. Regimen-related toxicity in patients undergoing bone marrow transplantation. J Clin Oncol 1988; 6: 1562–1568. | PubMed | ISI | ChemPort |
12. Przepiorka D, Weisdorf D, Martin P et al. 1994 consensus conference on acute GVHD grading. Bone Marrow Transplant 1995; 15: 825–828. | PubMed | ISI | ChemPort |
13. Kaplan EL, Meier P. Nonparametric estimation from incomplete observations. J Am Stat Assoc 1958; 53: 457–481. | Article | ISI |
14. Prentice RL, Kalbfleisch JD. The analysis of failure times in the presence of competing risks. Biometrics 1978; 34: 541–554. | Article | PubMed | ISI | ChemPort |
15. Dupriez B, Morel P, Demory JL et al. Prognostic factors in agnogenic myeloid metaplasia: a report on 195 cases with a new scoring system. Blood 1996; 88: 1013–1018. | PubMed | ISI | ChemPort |
16. Reilly JT. Pathogenesis and management of idiopathic myelofibrosis. Bailliere's Clin Haematol 1998; 11: 751–767. | ChemPort |
17. Rajantie J, Sale GE, Deeg HJ et al. Adverse effect of severe marrow fibrosis on hematologic recovery after chemoradiotherapy and allogeneic bone marrow transplantation. Blood 1986; 67: 1693–1697. | PubMed | ISI | ChemPort |
18. Creemers GJ, Lowenberg B, Hagenbeek A. Allogeneic bone marrow transplantation for primary myelofibrosis. Br J Haematol 1992; 82: 772–773. | PubMed | ISI | ChemPort |
19. Soll E, Massumoto C, Clift RA et al. Relevance of marrow fibrosis in bone marrow transplantation: a retrospective analysis of engraftment. Blood 1995; 86: 4667–4673. | PubMed | ISI | ChemPort |
20. Onida F, Kantarjian HM, Smith TL et al. Prognostic factors and scoring systems in chronic myelomonocytic leukemia: a retrospective analysis of 213 patients. Blood 2002; 99: 840–849. | Article | PubMed | ISI | ChemPort |
21. Fenaux P, Beuscart R, Lai JL et al. Prognostic factors in adult chronic myelomonocytic leukemia: an analysis of 107 cases. J Clin Oncol 1998; 6: 1417–1424.
22. Tefferi A, Hoagland HC, Therneau TM, Pierre RV. Chronic myelomonocytic leukemia: natural history and prognostic determinants. Mayo Clin Proc 1989; 64: 1246–1254. | PubMed | ISI | ChemPort |
23. Wattel E, Guerci A, Hecquet B et al. A randomized trial of hydroxyurea versus VP16 in adult chronic myelomonocytic leukemia. Groupe Francais des Myelodysplasies and European CMML Group. Blood 1996; 88: 2480–2487. | PubMed | ISI | ChemPort |
24. Beran M, Kantarjian H, O'Brien S et al. Topotecan, a topoisomerase I inhibitor, is active in the treatment of myelodysplastic syndrome and chronic myelomonocytic leukemia. Blood 1996; 88: 2473–2479. | PubMed | ISI | ChemPort |
25. Zang DY, Deeg HJ, Gooley T et al. Treatment of chronic myelomonocytic leukaemia by allogeneic marrow transplantation. Br J Haematol 2000; 110: 217–222. | Article | PubMed | ISI | ChemPort |
26. Sawyers CL. Chronic myeloid leukemia. N Engl J Med 1999; 340: 1330–1340. | Article | PubMed | ISI | ChemPort |
27. Storb RF, Champlin R, Riddell SR et al. Non-myeloablative transplants for malignant disease. Hematology (Am Soc Hematol Educ Progr) 2001; 375–391.
28. Champlin R, Khouri I, Shimoni A et al. Harnessing graft-versus-malignancy: non-myeloablative preparative regimens for allogeneic haematopoietic transplantation, an evolving strategy for adoptive immunotherapy. Br J Haematol 2000; 111: 18–29. | Article | PubMed | ISI | ChemPort |
29. Devine SM, Hoffman R, Verma A et al. Allogeneic blood cell transplantation following reduced-intensity conditioning is effective therapy for older patients with myelofibrosis with myeloid metaplasia. Blood 2002; 99: 2255–2258. | Article | PubMed | ISI | ChemPort |