Therapy-related myeloid neoplasms following treatment with radioiodine.

BACKGROUND: Few data are available on therapy-related myelodysplastic syndromes and acute myeloid leukemia developing after radioiodine treatment. DESIGN AND METHODS: We retrospectively analyzed 39 patients with myeloid neoplasms following radioiodine treatment, whose data were reported to the Duesseldorf Myelodysplastic Syndromes Register (8 of 3814 patients) and five other German Myelodysplastic Syndromes centers (n=31) between 1982 and 2011. These data were compared with those from 165 patients from our Myelodysplastic Syndromes Register with therapy-related myeloid neoplasms following chemotherapy (n=90), radiation (n=30), or radiochemotherapy (n=45). RESULTS: With a median latency of 79 months, 18 patients developed therapy-related acute myeloid leukemia and 21 presented with therapy-related myelodysplastic syndromes (8 refractory anemia with excess blasts I/II, 6 refractory anemia with multilineage dysplasia, 3 myelodysplastic syndromes with del(5q), 1 refractory anemia, 1 refractory anemia with ring sideroblasts, 1 chronic myelomonocytic leukemia II, 1 myelodysplastic/myeloproliferative neoplasm unclassifiable). Risk assessment according to the International Prognostic Scoring System was low-risk in 23%, intermediate-1 in 29%, intermediate-2 in 35%, and high-risk in 13%. Karyotype was abnormal in 68%, with chromosomes 7 (30%), 5 (26%), 8 (26%) and 3 (17%) being most frequently affected. No differences in the distribution of gender, World Health Organization subtype, acute myeloid leukemia progression, International Prognostic Scoring System score, and cytogenetic risk were observed between patients with therapy-related myeloid neoplasms following radioiodine or other treatment modalities. Of 17 patients who received induction chemotherapy, 71% were refractory to this treatment or died from treatment-related toxicity. The median overall survival in the entire group was 21.7 months (95%-CI 10.5-33 months) and did not differ significantly in comparison to the survival of patients with therapy-related myeloid neoplasms following other cytotoxic treatments. Patients with therapy-related acute myeloid leukemia had significantly inferior overall survival (12.4 versus 28.7 months, P=0.002). CONCLUSIONS: Patients developing a therapy-related myeloid neoplasm after radioiodine treatment usually present with biological characteristics similar to those seen in patients with therapy-related myeloid neoplasms following other cytotoxic treatment modalities, associated with a low response rate to induction chemotherapy and poor prognosis.

Plerixafor enables successful hematopoietic stem cell collection in an extensively pretreated patient with testicular cancer.

Plerixafor is a reversible CXCR4 antagonist that leads to a rapid release of hematopoietic stem and progenitor cells (HPSCs) from the bone marrow into the peripheral blood by interfering with the CXCL12-CXCR4 interaction. Based on two multicenter phase III studies, plerixafor in combination with granulocyte colony-stimulating factor (G-CSF) was approved by the Food and Drug Administration for autologous HPSC mobilization in patients with multiple myeloma and non-Hodgkin's lymphoma. We report the case of a 26-year-old man with testicular cancer who was extensively pretreated and failed to mobilize a sufficient number of HPSCs after cytotoxic chemotherapy and the administration of G-CSF and pegylated G-CSF (PEG-G-CSF). Using a combination of plerixafor, G-CSF and PEG-G-GSF after chemotherapy, a sufficient number of HPSCs could be collected for the support of 3 sequential high-dose therapies. The patient achieved a complete and uncomplicated engraftment following each cycle of HPSC-supported high-dose therapy. Patients suffering from advanced germ cell cancer may be another group that benefits from the use of plerixafor, which to date has only been approved for the treatment of multiple myeloma and lymphoma. To our knowledge, this is the first case report of successful mobilization of HPSCs with plerixafor in a patient with testicular cancer.

The monoclonal anti-VLA-4 antibody natalizumab mobilizes CD34+ hematopoietic progenitor cells in humans.

We investigated the role of adhesion molecule VLA-4 in CD34+ blood stem-cell mobilization. Therefore, we examined 20 patients with multiple sclerosis (MS) who were treated with the anti-VLA-4 antibody natalizumab. Treated patients had received a median number of 4 natalizumab infusions (range: 2-9 infusions). Blood samples were taken 4 weeks following the last infusion. With a median proportion of 7.6 CD34+ cells/microL (range: 2.2-30.4 cells/microL), these patients had a significantly higher (P=.003) amount of circulating CD34+ cells compared with 5 healthy volunteers (median: 1.4/microL; range: 0.6-2.4/microL) and 5 untreated MS patients (median: 1.0/microL; range: 0.5-1.7/microL) (P=.001). Serial measurements in 4 patients receiving their first natalizumab infusion showed a maximal significant increase in circulating CD34+ cells from 3.3/microL (range: 1.6-4.8/microL) to 10.4/microL (range: 7.5-12.04/microL) 72 hours following natalizumab infusion (P=.001), including pluripotent cells in colony-forming assays. This mobilizing ability of natalizumab might be useful for patients with poor response to granulocyte colony-stimulating factor (G-CSF)-based protocols.