Prospective study of a modified posttransplant cyclophosphamide regimen for severe aplastic anemia patients with HLA-haploidentical transplantation

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a curative modality for severe aplastic anemia (SAA). The availability of haploidentical donors has expanded valid choices for SAA. However, previous posttransplantation cyclophosphamide (PTCy)-based protocols for HLA-haploidentical HSCT in SAA patients are associated with relatively delayed neutrophil and platelet engraftment. We prospectively studied HLA-haploidentical HSCT using bone marrow combined with peripheral blood stem cells as grafts and a modified PTCy regimen for treating SAA; we evaluated the efficacy and safety of this regimen, which had an increased dose (from 4.5 mg/kg to 6.0 mg/kg) and backward adjusted timing (from day -9 to -7 to day -5 to -3) of antithymocyte globulin (ATG) compared with previous PTCy protocols. Seventy-one eligible patients were included in this prospective study between July 2019 and June 2022. The median time to and cumulative incidence (CI) of neutrophil and platelet engraftment were 13 days (range, 11-19) and 97.2±2.2% and 12 days (range, 7-62) and 94.4 ± 2.9%, respectively. Five patients experienced graft failure (GF), including 2 with primary GF and 3 with secondary GF. The CI of GF was 7.0±3.1%. The interval between diagnosis and transplantation (≥1 year) was a risk factor for GF development (HR 8.40, 95% confidence interval (1.40-50.47), p=0.02). No patients developed grade IV acute graft-versus-host disease (aGVHD) or severe chronic GVHD (cGVHD). The 100-day CI of grade II-IV aGVHD and 2-year cGVHD were 13.4±4.2% and 5.9±2.9%, respectively. With a median follow-up of 580 days (range, 108-1014) for 63 survivors, the estimated 2-year overall survival (OS) and 2-year GVHD-free and failure-free survival (GFFS) were 87.3% (95% confidence interval, 79.4-96.0) and 83.8% (95% confidence interval, 74.9-93.7), respectively. In conclusion, the PTCy regimen with an increased dose and backward adjusted timing of ATG is an effective and feasible choice for treatment with HLA-haploidentical HSCT using BM combined with PBSCs as grafts, with a high rate of and faster engraftment, a low rate and intensity of aGVHD and cGVHD, and prolonged OS and GFFS.

The effect of hematopoietic stem cell transplantation on fertility and strategies for improvement

Ovarian dysfunction is an important consequence of hematopoietic stem cell transplantation (HCT). Premature ovarian failure and infertility can severely impact the quality of life for the increasing number of female long-term survivors of HCT. Here, we review the impact of HCT on ovarian function, post-transplant fertility and birth outcomes, and the contemporaneous strategies to preserve fertility for these patients.

Factors predicting endocrine late effects in childhood cancer survivors from a Japanese hospital

We retrospectively analyzed endocrine late effects in 81 childhood cancer survivor (CCS) patients who had been referred to our endocrinology department in Chiba Children's Hospital between January 1, 2008 and December 31, 2016. Among 69 eligible patients (33 male, 36 female), endocrine late effects were identified in 56 patients (81.1%). The median age at the last visit to our endocrinology department was 17.4 years (range: 7.1-35.3 years). The most common primary cancer was acute lymphoblastic leukemia (22 patients, 31.8%). Forty-four patients (64%) were treated using radiation therapy. A primary brain tumor and high doses (≥6 g/m²) of cyclophosphamide were significantly associated with growth hormone deficiency (GHD). Our present study suggests that high doses of cyclophosphamide is a risk factor for GHD. Adult heights and pubertal growth spurts of patients treated with radiation therapy were significantly lower than patients not treated with radiation therapy. Our retrospective study reconfirmed that hematopoietic stem cell transplantation and chronic graft versus host disease (GVHD) were associated with elevated risks of primary hypothyroidism. However, it is unclear whether GVHD induces thyroid dysfunction. Gonadal radiation and busulfan were associated with primary hypogonadism as reported in previous studies. We found high doses of cyclophosphamide to be involved in pituitary disorders. We suggest that pediatric endocrinologists should discuss the potential effects of radiation therapy on adult height and pubertal growth spurt in CCS patients. Moreover, patients who have been treated with high doses of cyclophosphamide or have chronic GVHD require long-term follow-up for endocrine late effects.

Fludarabine, cytarabine, granulocyte colony-stimulating factor and melphalan (FALG with L-PAM) as a reduced toxicity conditioning regimen in children with acute leukemia

BACKGROUND

The conventional conditioning regimen for patients with leukemia prior to allogeneic stem cell transplantation is myeloablation to eradicate residual leukemic cells and host immunocompetent cells. This helps prevent leukemic relapse as well as rejection after transplantation. A myeloablative conditioning regimen with busulfan (BU) or total body irradiation (TBI) is effective for eradication of leukemic cells but is also associated with significant toxicities in the acute or late phase in pediatric patients. In an effort to minimize these adverse effects, we conducted bone marrow transplantation (BMT) from unrelated volunteer donors using a conditioning regimen without BU or TBI.

PROCEDURE

Ten patients with acute leukemia in first or second remission were given a "non-BU, non-TBI conditioning regimen," which consisted of fludarabine (FLU), cytarabine (CA), and melphalan (L-PAM) after FLAG combined with L-PAM.

RESULTS

Engraftment was obtained in all patients, and two patients died of relapse. Eight of 10 patients have been disease-free for a median of 126 months (116-142) after transplantation. The overall survival, event-free survival, relapse rate, and treatment-related mortality were 80.0%, 80.0%, 20.0% and 0.0%, respectively. In female patients, spontaneous menstruation with normal luteinizing hormone (LH), follicle stimulating hormone (FSH), and estradiol (E2) levels was observed in all four patients at post-pubertal age.

CONCLUSIONS

This conditioning regimen of FLAG combined with L-PAM (which did not contain BU and TBI) was associated with good outcomes and minimal late adverse effects in children with acute leukemia who have undergone allogeneic BMT from unrelated volunteer donors.

Endocrinological analysis of 122 Japanese childhood cancer survivors in a single hospital

With recent improvements in the diagnosis and treatment of cancer, the number of childhood cancer survivors (CCSs) has been increasing in Japan. The importance of quality of life during the lifetime of CCSs has now been recognized, and the late effects of cancer treatments are essential and important issues. In this study we analyzed the endocrinological abnormalities of CCSs by retrospectively evaluating 122 outpatients (62 males and 60 females) who had been referred from pediatric oncologists to our follow-up clinic among 151 CCSs attending our hospital more than two years after their cancer treatment. Follow-up duration varied from 2 to 30 (median 8.0) years. Their average age was 17.3 (range 4-36, median 17.0) years, and 38 patients (31.1%) reached adulthood. Endocrinological abnormalities were found in 82 (67%) of 122 survivors. Gonadal dysfunction was observed in 60 patients (49%). Thirty-nine patients (32%) were short or grew at a slower rate. Twenty-six patients (21%) showed thyroid dysfunction. Other abnormalities were as follows: obesity in 20 patients (16%), leanness in 10 (8%), central diabetes insipidus in 11 (9%) and adrenocortical dysfunction in 9 (7%). Low bone mineral density was observed in 41 (42%) of 98 patients evaluated. These endocrinological abnormalities were caused by the combined effects of cancer itself and various treatments (chemotherapy, radiation therapy, surgery, and hematopoietic stem cell transplantation). Lifetime medical surveillance and continuous follow-up are necessary for CCSs, because treatment-related complications may occur during childhood and many years after the therapy as well. Endocrinologists should participate in long-term follow-up of these survivors in collaboration with pediatric oncologists.