Clinical and morphological features of paediatric myelodysplastic syndromes: a review of 34 cases.

BACKGROUND: The clinical and morphological spectrum of myelodysplastic syndromes (MDS) during childhood has not yet been completely documented. We herein present the clinical features and morphological data from peripheral blood (PB), bone marrow aspirates (BMA) and bone marrow biopsies (BMB) of a series of paediatric MDS patients, with particular emphasis on their specific morphological characteristics and their diverse underlying genetic background. PATIENTS AND METHODS: Thirty-four patients with MDS (median age 8.45 y) were consecutively diagnosed and treated during a period of 15 y (1988-2002). Diagnosis was based on clinical manifestations, morphology of PB, BMA and BMB, and cytogenetic analysis of BM cells. Clonogenic methylcellulose cell cultures were performed in 23/34 patients. Patients were categorized into group A [26 primary/de novo MDS, i.e. refractory anaemia (RA) 18, RA with excess of blasts (RAEB) 2, RAEB in transformation (RAEB-t) 6] and group B (8 secondary MDS, i.e. RA 4, RAEB 1, RAEB-t 3). Treatment options varied according to protocols active during the period of the study and the availability of a suitable BM donor. Survival probabilities were estimated using the Kaplan-Meier method. RESULTS: Dysplastic features of the erythroid, myeloid and megakaryocytic lineage were detected at BMA in 85%, 50% and 90% of the patients, respectively, while decreased cellularity was found at BMB in 21/34 patients (60%). RA patients of group A presented at BMB significant hypocellularity (14/18) as a prominent finding due to decrease of the myeloid (13/18 patients) and/or the megakaryocytic (14/18 patients) lineage. Hypocellularity in RA was accompanied by dysplasia of the erythroid (17/18 patients) and megakaryocytic (16/18 patients) lineage, the presence of abnormal localization of immature precursors (ALIP, 8/18 patients), fibrosis (5/18) and stromal changes (11/18). Chromosomal aberrations were revealed in 17/34 patients, of which monosomy 7 was present in seven. Cell cultures demonstrated abnormal myeloid and/or erythroid in vitro clonal growth pattern in all the examined patients. An associated disorder or inherited disease, was identified in 14/26 patients (54%) with primary MDS. Cumulative survival of group A patients was 44.2% (RA 66.6%, RAEB/RAEBt 14.6%; p = 0.001), and of the whole group 42.4%, at 14 y. CONCLUSIONS: Hypocellularity of significant degree is a constant and prominent feature among paediatric MDS, especially those with RA. A large variety of associated disorders underlies the clinical appearance of paediatric MDS, reflecting their marked heterogeneity. RA represents the prominent subtype during childhood (69% in this study), and it appears to have the best prognosis, while prognosis of RAEB/RAEBt remains extremely poor.

Insulin-like growth factor-I and binding protein-3 in relation to childhood leukaemia.

The aetiology of most cases of childhood leukaemia remains unknown, but several studies have indicated that increased birthweight and height are risk factors for the disease. Since insulin-like growth factor-I (IGF-I) mediates the effect of growth hormone and has been positively associated with prostate cancer, we have evaluated the role of this hormone and its principal binding protein, IGFBP-3, in the aetiology of childhood leukaemia. Incident cases of childhood leukaemia from those recorded by a national network of childhood oncologists were enrolled in our study. Controls were children hospitalised for acute conditions of no more than moderate severity with matching for gender, age and maternal place of residence. Blood measurements of IGF-I and IGFBP-3 were undertaken using commercially available radioimmunoassays. Serum IGF-I values decreased by about 1.7% per month, and the rate of decline was higher, though not significantly so, among cases (2.1% per month) than among controls (1.4%). There was no significant association between IGF-I and the likelihood of childhood leukaemia, but an increment of 1 microg/ml of IGFBP-3 was associated with a substantial and statistically significant reduction of childhood leukaemia by 28% (95% confidence interval 7% to 45%). Because IGFBP-3 is essentially a binding protein, we interpret our findings as indicating that bioavailable IGF-I may play an important role in the aetiology of childhood leukaemia. The much smaller quantities and the inherent instability of IGF-I in the blood in comparison to those of IGFBP-3 are likely to hinder documentation of an underlying positive association of IGF-I with the disease.

Electrical power lines and childhood leukemia: a study from Greece.

Residential proximity to electrical power lines of different voltage in relation to childhood leukemia was investigated through a case-control study undertaken in Greece during 1993-1994. The study comprised 117 incident cases of childhood leukemia and 202 age-, gender- and place-of-residence-matched controls. Four measures of exposure to magnetic fields were developed, using data provided by the Public Power Corporation of Greece: Voltage (V) divided by the distance (d), V/d2, V/d3 and an adaptation of the Wertheimer-Leeper code. Conditional-logistic-regression modeling was used to adjust for potential confounding influences of 18 variables. No significant trends of childhood leukemia risk with increasing exposure levels were noted, nor were there statistically significant elevations of disease risk at the higher exposure levels in each measure of exposure. These results do not support a causal link between residential proximity to electrical high-voltage wires and childhood leukemia risk, but in themselves do not refute a weak empirical association.

The risk profile of childhood leukaemia in Greece: a nationwide case-control study.

The risk profile of childhood leukaemia in Greece was studied through a case-control investigation that included all 153 incident cases of the disease, ascertained throughout the country during 1993 and 1994, and two hospital controls for every case matched for gender, age and place of residence. The data were analysed using conditional logistic regression and the associations are expressed in terms of adjusted odds ratios (OR) and their 95% confidence intervals. Cases were born to mothers of a higher standard education, the OR for an increment of four schooling years being 1.48 (1.17-1.87) and had higher birth weight, the OR for an increment of 500g being 1.36 (1.04-1.77). Pet ownership and birth after a pregnancy with anaemia were associated with increased risk, the ORs being 2.18 (1.14-4.16) and 2.60 (1.39-4.86) respectively. From the frequency analyses, indicative inverse associations were found with birth order, household crowding and previous hospitalization with allergic diseases, whereas indicative positive associations were found with diabetes mellitus during pregnancy and with neonatal jaundice. Substantial or significant elevations were not found with respect to maternal smoking and coffee drinking during pregnancy, diagnostic radiography and ultrasonographic examinations or blood transfusions. A significant inverse association with maternal consumption of alcohol could be due to multiple comparisons, but a detrimental effect can probably be excluded. A non-significant positive association with total shots of viral vaccinations and a weak non-significant inverse association with breast feeding were also found. We interpret the findings of this study as being compatible with acute childhood leukaemia being linked with delayed development of herd immunity to fairly common infectious agents, in conjunction with accelerated perinatal and early post-natal growth.

Immune response of immunocompromised children with malignancies to a recombinant hepatitis B vaccine.

The aim of this study was to interpret the antibody response to hepatitis B vaccination following an intensified four-dose schedule in 140 cancer patients who presented at our clinic between January 1, 1993 and December 31, 1994. According to therapy status, the patients were divided into two groups: group A consisted of 76 patients undergoing chemotherapy and group B of 64 patients in complete remission and off treatment. The eligibility requirements were negative hepatitis B virus (HBV), HCV, and human immunodeficiency virus serologic markers. A total of four dose (20 micrograms per dose) of recombinant HB vaccine was administered intramuscularly in the deltoid region at 0, 1, 2, and 6 months. Blood from the vaccinated subjects was obtained at months 1, 2, 3, and 7 in order to measure anti-HBs titer levels. Protective anti-HBs titers were considered to be those > or = 10 mIU/mL. The overall seroconversion rate 1 month after the fourth dose was 57% (80/140 patients), and the seroconversion rates for groups A and B were 31.5% (24/76 patients) and 87.5% (56/64 patients), respectively. Our results indicated that immunocompromised children undergoing chemotherapy (although less responsive than children in complete remission and off treatment) still preserved their potential to produce protective titers of anti-HBs. On this basis we recommend (1) HB vaccination after diagnosis of malignancy in pediatric patients whenever a high prevalence of HB infection exists and (2) vaccination of patients of therapy and in complete remission.

Secondary malignancies in a child with Hodgkin's disease: T-cell lymphoma and myelodysplastic syndrome evolving into acute nonlymphoblastic leukaemia.

Hodgkin's disease (HD) has been linked to an increase risk of second malignant neoplasms (SMN), especially non-Hodgkin's lymphoma (NHL) and acute nonlymphoblastic leukaemia (ANLL). The mutagenic property of cytotoxic therapy as well as defective immunity have been implicated as playing a major role in the development of SMN in patients previously treated for HD. We report a case of a 14-year-old girl with HD who developed two different second malignancies within a latent period of 28 months following HD diagnosis. The patient presented initially with bilateral cervical and supraclavicular as well as mediastinal and paraaortic lymphadenopathy. She was staged as IIIA, nodular sclerosing type HD, and was given eight alternative cycles of MOPP-ABVD followed by "mantle" field radiotherapy to a total dose of 3.3 Gy plus 0.4 Gy to the upper mediastinum. Within 8 months following the completion of therapy, a period of myelodysplasia and progressive severe immune deficiency, considered as a result of initial treatment, occurred. Eighteen months after HD diagnosis while the patient was continuously neutropenic and heavily immunocompromised, a peripheral T-cell lymphoma of the angiocentric immunoproliferative lesion type (AIL) Grade III, appeared in both lungs within and beyond the radiation field, with no evidence of HD in biopsy specimens. After institution of a new chemotherapy regimen (L17M), a satisfactory response regarding NHL lesions was noted. However, 10 months later the myelodysplastic syndrome (MDS) accompanied by complex chromosomal abnormalities evoluted to frank ANLL with a rapid fatal course. This case supports the hypothesis that combined modality treatment accompanied by severe immunodeficiency may result in the development of multiple second malignancies even within a very short latent period, especially in a subgroup of HD patients who may be particularly increased risk of second cancers.

Dihydrofolate reductase activity in primary brain tumors in children.

PURPOSE: Dihydrofolate reductase is an enzyme involved in cell proliferation and differentiation processes. A cytochemical method was used to detect and quantitate this enzyme at the cellular level in brain tumors in children. MATERIAL AND METHODS: Twenty-six children, aged 1-12 years, with primary brain tumors were studied, eight with medulloblastoma, 10 with glioma, and eight with ependymoma or other tumors. The cytochemical technique was applied on touch preparations performed in the operating room form biopsy specimens. RESULTS: Enzyme activity was apparent as cytoplasmic granules sometimes overlying the nucleus of tumor cells. CONCLUSIONS: Activity of dihydrofolate reductase in the children with medulloblastomas and high-grade gliomas was higher than that reported in leukemic blast cells. In the other brain tumors, low grade gliomas, and ependymomas, the enzyme activity was weaker.