On March 3, 1991,the first hematopoietic stem cell transplantation was performed in this center. From March 1991 through April 2011, a total of 3237 first hematopoietic stem cell transplantations were carried out.
The male/female ratio of patients was 1331/874 in allogeneic, 613/403 in autologous, and 11/5 in syngeneic group patients. The median age of patients was 20 years (range: 0-63) in allogeneic, 33 years (range: 2-71) in autologous, and 20 years (range: 11- 36) in syngeneic.During that time, 2205 patients were treated by myeloablative and non-myeloablative chemotherapy regimen followed by allogeneic stem cell transplantation (SCT), at the Hematology-Oncology and Stem Cell Transplantation Research Center.
The transplanted diseases which are sorted by frequency include: acute myelogenous leukemia (n=590), thalassemia major (n=508), acute lymphoblastic leukemia (n=244), chronic myelogenous leukemia (n=240), severe aplastic anemia (n=183), Fanconi anemia (n=62), myelodysplastic/Myeloproliferative syndromes/ paroxysmal nocturnal hemoglobinuria (PNH) (n=57), non-hodgkin’s lymphoma (n=31), multiple myeloma (n=13), leukocyte adhesion deficiencies (n=12), osteopetrosis (n=11), chronic lymphoblastic leukemia (n=8), Hodgkin’s disease (HD) (n=6), severe combine immunedeficiency (n=5), sickle cell thalassemia (n=4), Chediak-Higashi syndrome (n=3), breast cancer (n=3), Niemann-Pick disease (n=3), Hurler syndrome (n=3), renal cell carcinoma (n=2), sickle- cell disease (n=2), neuroblastoma (n=1), plasma cell leukemia (n=1), Histiocytosis- X (n=1), rhabdomyosarcoma (n=1) and congenital neutropenia (n=1).
The donor types of SCTs were Human–leukocyte- antigen (HLA) histocompatible siblings (n=2054), HLA-matched other relatives (n=73), HLA-mismatched siblings (n=56), and HLA mismatched unrelated (n=22). The patients who were treated by allogeneic SCT received a median of 9.44×108/kg nucleated cells infused (range: 0.93 – 33.29×108/kg).
From March 1991 through April 2011, 1016 patients were treated by intensive chemotherapy followed by reinfusion of non-cryopreserved autologous stem cells.Thepatients had the following diseases: multiple myeloma (n=280), AML (n=228), HD (n=215), NHL (n=182), ALL (n=25), neuroblastoma (n=16), Ewing's sarcoma (n=9), breast cancer (n=8), plasmacell disorders (n=8), testicular cancer (n=7), amyloidosis (n=7), germ cell tumor (n=6), systemic sclerosis (n=4), medulloblastoma (n=4), ovarian cancer (n=3), plasma cell leukemia (n=2), nasopharyngeal carcinoma (n=1), Wilms' tumor (n=1), pancreatoblastoma (n=1), and multiple sclerosis (n=1) ().
Diseases Transplanted With Graft Types
3.3. Infused Cell Counts
The patients who were undergoneautologous SCT received a median of 6.96×108/kg (0. 1 – 33.25×108/kg) nucleated marrow cells. During this period, 16 patients were treated by syngeneic SCT. Their diseases were ALL (n=8), AML (n=5), severe aplastic anemia (n=2), and NHL (n=1). They received a median of 6.26×108/kg (3.8– 9.22×108/kg) nucleated marrow cells infusion. Stem cells were obtained and then infused without purging.
3.4. Post-transplant Care
Patients were nourished by special and sterilized food and special diet according to each patient characteristics and needs. They were observed closely for GvHD complications and their treatment. All patients were treated in completely isolated rooms during the pre and post-transplantation period. They were conventional, private and High-Efficiency Particulate- Arresting (HEPA) filtered rooms with minimal entertainment to avoid patient depression during hospitalization period (12
3.5. Data Gathering
The Hematology - Oncology and Stem Cell Transplantation Research Center has a data management office, consisting of gathering data group which collect data from the stem cell transplantation wards, check reports for completeness and correctness and identify missing data.They will report missing fields and after completing them, enter data report forms into the computer database program (software version 3.2.4 which meets the needs of hematopoietic stem cell transplantation centers) for statistical analysis. Preparation of statistical reports and writing articles are the other line of works. This office controls the quality of data-entry process. It is responsible for advising patients with providing information about stem cell transplantation process and its consequences and its needed personal cares.
Endpoints: In this study, endpoints were disease-free survival (DFS), overall survival (8
), morphologic leukemia relapse (hematologic and/or extramedullary), acute and chronic GvHD. OS was measured as the time interval between the date of transplantation and the date of death due to any cause; surviving patients were censored at the date of last contact. DFS was defined as time to clinical or hematologic relapse or death from any causes other than relapse; patients who remained alive in complete remission were censored at time of last contact. For analyses of acute GvHD (aGvHD), patients alive at100thday without having experienced aGvHD considered censored. Chronic GvHD is defined only for patients surviving at least 100 days after transplantation; patients without chronic GvHD (cGvHD) were censored at last contact.
Definitions: the total hematopoietic stem cell transplantation number, here, points to the number of first-time patients treated with hematopoietic stem cell transplantation. After first HSCT, if relapse or rejection occurs, in special cases, we use unplanned HSCT known as re-transplantation. Donor lymphocyte infusion (DLI) is a method of treatment for patients with recurrent or persistent malignancy after allogeneic HSCT, with an infusion of additional lymphocytes obtained from the original donor, without the cover of immunosuppressive agents (13
).Cell therapy is a technology that introduces the new cells (potential stem cells) to adiseased or malfunction organ in order to replace the new healthy and functional tissue with damaged one.
3.6. Statistical Analysis
The groups were compared by using Mann-Whitney U test for continuous variables and chi-square test for categorical variables. Overall and disease-free survival curves were calculated by the Kaplan-Meier method (14
); and groups were compared by using the Log-Rank test statistic (15
). Death before 100th
day considered as a competing event for acute GvHD. Death after 100th
day was considered as a competing event for chronic GvHD. Groups were compared by the Grays' method in the competing risk settings (16
).The level of significance was set to 0.05. The packages cmprsk (17
) and survival (18
) in the R software (18
) were used to conduct the statistical analyses.