Leukemia in a child with a history of medulloblastoma

Treatment-related myelodysplastic syndrome after temozolomide for recurrent high-grade glioma

In patients with recurrent malignant glioma, treatment-related myelodysplastic syndrome (t-MDS) and acute leukemia are rare adverse effects because the median survival after relapse is limited. We report a 44-year-old woman with t-MDS (refractory anemia with excess blasts) following treatment of recurrent anaplastic astrocytoma with temozolomide (TMZ). A cytogenetic study showed del (3)(q11.1). MDS was diagnosed 8.4 months after beginning TMZ. The disease rapidly evolved into acute leukemia within 1 month after the onset of MDS, and the patient died 1 month later during induction chemotherapy. The prognosis of t-MDS is generally poor. Considering the increasing use of TMZ, which is regarded as a drug with moderate toxicity, careful follow-up with routine blood testing is vital.

Cancer Risk Following Growth Hormone Use in Childhood

The therapeutic use of growth hormone (GH) has caused concern, as it is anabolic and mitogenic, and its effector hormone, insulin-like growth factor (IGF)-I is anti-apoptotic. As both hormones can cause proliferation of normal and malignant cells, the possibility that GH therapy may induce cancer, increase the risk of tumour recurrence in those previously treated for a malignancy, or increase the risk of cancer in those with a predisposition, has resulted in concerns over its use. There are theoretical and epidemiological reasons that suggest GH and IGF-I may be important in tumour formation and proliferation. Malignant tumours have been induced in animals exposed to supraphysiological doses of GH, whereas hypophysectomy appears to protect animals from carcinogen-induced neoplasms. In vitro, proliferation and transformation of normal haemopoetic and leukaemic cells occurs with supraphysiological doses of GH, but not with physiological levels. IGF, IGF binding proteins (IGFBP) and IGFBP proteases influence the proliferation of cancer cells in vitro; however, GH is probably not involved in this process. Epidemiological studies have suggested an association between levels of IGF-I and cancer, and an inverse relationship between IGFBP-3 and cancer; however, these associations have been inconsistent. A number of studies have been undertaken to determine the risk of the development of cancer in children treated with GH, either de novo, or the recurrence of cancer in those previously treated for a malignancy. Despite early concerns following a report of a cluster of cases of leukaemia in recipients of GH, there appears to be no increased risk for the development of leukaemia in those treated with GH unless there is an underlying predisposition. Even in children with a primary diagnosis of cancer, subsequent GH use does not appear to increase the risk of tumour recurrence. However, a recent follow-up of pituitary GH recipients has suggested an increase in colorectal cancer. In addition, follow-up of oncology patients has suggested an increase in second neoplasms in those who also received GH therapy. These studies emphasise the importance of continued surveillance both internationally with established databases and also nationally through single-centre studies.

Acute leukemia following treatment of malignant glioma

We report two patients with acute myeloid leukemia (AML) following therapy for malignant glioma; one was a young women treated heavily with alkylating agents for glioblastoma and the other a young man treated with high doses of procarbazine, lomustine, and vincristine (PCV) for anaplastic astrocytoma. We found 26 other examples of therapy related leukemia in adult and pediatric brain tumor patients. Including our two, there were 12 patients with malignant glioma; median interval from treatment to diagnosis of AML was 31 months. Nine adult malignant glioma patients all received nitrosoureas, some as the sole form of chemotherapy. No definite cases occurred after radiotherapy alone. Based upon analogy with other cancers, the cumulative dose of chemotherapy, especially alkylating agents, is the major risk factor for development of secondary AML. Agents implicated include carmustine (BCNU), lomustine (CCNU), and procarbazine. Conventional radiotherapy appears not to confer additional risk. Progressive macrocytosis, early dose reductions for thrombocytopenia, and refractory anemia may provide early diagnostic clues. Current glioma therapy is leukemogenic but the number of patients who survive the interval required to induce AML is small; nevertheless, the identification of chemosensitive types of glioma, and subgroups of patients who derive the most benefit from chemotherapy, may result in increasing numbers of patients at risk of long term complications. If regimens such as PCV continue to prove valuable in neurooncology the risk of leukemia will require integration into the clinical decision process. A search for more effective therapy with minimal mutagenicity remains critical.

Occurrence of acute megakaryoblastic leukemia in a patient with idiopathic growth hormone deficiency

We describe a case of a 15 year old boy who developed acute megakaryoblastic leukemia (AMKL) while receiving treatment with human growth hormone (hGH) for idiopathic growth hormone deficiency (GHD). He was diagnosed as having idiopathic GHD and given hGH from December 1991. The examination of his peripheral blood showed mild pancytopenia 2 months before the start of the hGH therapy. Since January 1992, paleness of the skin, general fatigue and fervescence progressed gradually. In February 1992, because of the occurrence of acute leukemia, administration of hGH was discontinued. Judging from the results of surface marker analysis of the blast cells, the patient was diagnosed as having AMKL. He was treated with chemotherapy for acute non-lymphoblastic leukemia from March 1992. A complete remission was obtained after 4 weeks of treatment. The chemotherapy was completed in July 1993. He remains in complete remission 26 months after diagnosis. This case suggests the importance of hematological examination and, when there is any abnormality which is not caused by GHD, such as pancytopenia, more detailed medical examinations (for example bone marrow examination) are necessary.

Acute lymphoblastic leukemia in a girl treated for osteosarcoma

Acute lymphoblastic leukemia (ALL) was diagnosed in a 13-year-old girl who had been treated previously for osteosarcoma of the left distal femur (23 months after her first cancer onset and 12 months after the end of treatment). The patient started chemotherapy for ALL and achieved complete remission; she is in continuous complete remission 5 years after the diagnosis of secondary ALL and 7 years after the onset of osteosarcoma.

Involvement of 11p15 and 3q21q26 in therapy-related myeloid leukemia (t-ML) in children. Case reports and review of the literature

The cytogenetic findings of therapy-related myeloid leukemia (t-ML) in three children are presented. These included one male patient with acute lymphoblastic leukemia (ALL) who underwent bone marrow transplantation and developed therapy-related myeloproliferative disease (t-MPD) in the female-donor hematopoietic cells 2.5 years after receiving radiation and epipodophyllotoxin therapy for ALL testicular relapse. Bone marrow leukemic cell karyotype revealed 46,XX,add (11)(p15) and a normal female karyotype in the peripheral blood lymphocytes. The other two children, one with ALL and one with ganglioneuroblastoma, developed fatal t-MPD and therapy-related acute myeloblastic leukemia (t-AML) preceded by myelodysplastic syndrome (t-MDS), respectively, 5 years after diagnosis, following administration of alkylating agents and irradiation. Monosomy 7 was present in both, and was combined with inv(3)(q21q26) in the second patient. Our review of the cytogenetic findings in 91 previously reported pediatric patients with t-ML suggested that the involvement of 11p15 and 3q21-->23, 3q24-q26 with or without a combination of translocation 11q23 and -7/7q-, respectively, are nonrandom aberrations of t-ML in children. Comparison of the chromosomal changes in t-ML between the pediatric and an adult series revealed some differences which may result from differences in treatment modalities and which, in addition, may indicate a possible role of genetic and/or age-dependent factors in the pathogenesis of therapy-related leukemogenesis in children.

Acute lymphoblastic leukemia following optic glioma treated by radiotherapy and surgery

A 14-year-old girl was diagnosed as having acute lymphoblastic leukemia following 5000 cGy cranial radiotherapy for treatment of optic glioma. In the absence of underlying predisposing factors, development of acute leukemia was attributed to the oncogenic effect of radiation.

Late leukemic relapse 10 years from diagnosis in a child on recombinant human growth hormone

A 12 year-old girl developed a late relapse of acute lymphoblastic leukaemia (ALL) 10 years from first presentation. Initial chemotherapy included vincristine, methotrexate, prednisolone, and L-asparaginase with cranial radiotherapy (18 Gy) for central nervous system prophylaxis. Documented growth failure led to recombinant human growth hormone (rhGH) replacement therapy being instituted in May 1989, 6 years from end of therapy and 2 years prior to relapse. Three independent experiments demonstrated no increased cell proliferation in vitro when the patient's thawed cryopreserved fresh leukemic cells were incubated with rhGH. However, a pre-T ALL cell line (PER-255) consistently demonstrated enhanced proliferation when incubated with rhGH (132.1 +/- 13.4%, P < 0.01). Growth hormone has been associated with an increased incidence of leukemia and may be implicated in the late relapse of this child. The use of growth hormone in children with a past history of ALL needs to be examined critically in the light of the potential risk of inducing leukemic relapse.

Conventional and nonconventional uses of growth hormone

Although GH has been available as a therapeutic agent for the GH-deficient child for more than 30 years, the conditions of its use have yet to be optimized. The availability of biosynthetic material has provided researchers with the opportunity to develop the protocols necessary to begin to finally answer the most fundamental questions pertaining to dose, frequency, and duration of treatment. It has also permitted the initiation of prospective trials in a large number of conditions that result in childhood short stature, with the expectation that some or many of them will be treated effectively and safely. Finally, it has opened the door to an entire spectrum of potentially new uses of GH and other growth factors for so-called nonconventional indications. That these have implications that range from the short-term rapid healing of a burn graft site, to the more efficient induction of ovulation, to the long-term preservation of lean body mass has excited the interest of investigators in many fields of medicine and physiology. Thus, the recent progress reported in this paper is really the beginning of the new research that will take place with GH and growth factors.