Elevation of cerebrospinal fluid sialic acid concentration in children with central nervous system leukemia

Clinical use of tumor markers in childhood malignancies

Tumor markers are developmentally regulated proteins or carbohydrate molecules, which are expressed in specific tissues in the fetus during certain developmental periods. With malignant transformation, these molecules are reexpressed in neoplastic tissues. Some developmental or metabolic disorders can also lead to the expression of tumor marker genes, hereditary tyrosinaemia and ataxia teleangiectasia associating with elevated serum alpha-fetoprotein are examples of such conditions. In pediatric malignancies, the most common markers in clinical use are alpha-fetoprotein in liver and yolk sac tumors, chorionic gonadotropin in germ cell tumors, and catecholamines and neuron specific enolase in neuroblastoma. Several other molecules including carbohydrate antigens CA 19-9 and CA 125 may also have a role in the diagnosis and follow-up of distinct types of childhood malignancies. The non-specificity of several markers, such as tissue polypeptide antigen and sialic acid, greatly hampers their clinical use. In this review we will discuss the biology and current knowledge on the use of serum and urine tumor markers. We also highlight the putative future use of these molecules in cancer diagnosis and therapy, including the use of monoclonal antibodies directed against these antigens.

Elevated cerebrospinal fluid fibronectin concentration at diagnosis indicates poor prognosis in children with acute lymphoblastic leukemia

We investigated whether the concentration of fibronectin (FN) in the cerebrospinal fluid (CSF) could be used for identifying patients with subclinical blast-cell infiltration in the central nervous system (CNS) and an increased risk of CNS relapse later in the course of their leukemia. Our series comprised 36 children with newly diagnosed acute lymphoblastic leukemia (ALL). The mean follow-up time was 54 months (range 5 to 96 months). The median concentration of CSF-FN at diagnosis was 2.24 mg/l (range 0.78 to 7.04 mg/l). The 3-year continuous complete remission rate for the 16 patients with CSF-FN concentrations less than or equal to 2 mg/l was 93% as compared with 37% for the 19 patients with CSF-FN greater than 2 mg/l (p = 0.001). When multivariate analysis was performed, the CSF-FN concentration retained its prognostic significance. When all relapses were considered as failures, the relative risks of relapse for patients with CSF-FN less than or equal to 2 mg/l and greater than 2 mg/l were I and 15.8 (95% confidence limits 1.8-135.6, p less than 0.02), respectively. If only CNS relapses (isolated and combined) were considered as failures, relative risks for the above-mentioned groups were I and 11.6 (1.4-99.5, p less than 0.05), respectively. We conclude that determination of the CSF-FN concentration may provide a new means of evaluating the CSF in children with ALL and may prove to be a sensitive indicator of leukemic CNS infiltration.

Malignant cell glycoproteins and glycolipids

The cell surface is involved in cell growth and division, cell-cell interaction, communication, differentiation and migration, and other processes likely to be involved in malignant transformation and/or the metastatic spread of cancer. Although there are many alterations of glycoproteins and glycolipids on the malignant cell surface, it is unclear whether these alterations are epiphenomena or an integral part of the malignancy process. This article reviews the recent literature and some earlier studies relevant for understanding emerging concepts and trends with respect to malignant cell glycoconjugates. Emphasis is on structural alterations of the carbohydrate portions of malignant cell glycoproteins and glycolipids and on the enzymes (glycosyltransferases and glycosidases) involved in their metabolism. Practical applications derived from malignant cell glycoconjugate studies are discussed briefly with respect to the diagnosis, staging, monitoring, and treatment of malignant disease. The review concludes by indicating which research areas on malignant cell glycoconjugates are likely to be fruitful in increasing our basic understanding of, and ability to deal effectively with, malignant disease.

Elevated cerebrospinal fluid leukocyte count and protein concentration at diagnosis: independent risk factors in children with acute lymphoblastic leukemia

The aim of this study was to investigate whether determination of the initial cerebrospinal fluid (CSF) protein concentration and leukocyte count in children with acute lymphoblastic leukemia (ALL) could yield useful information about the patient's central nervous system status and prognosis. The population-based unselected series comprised 160 children. The mean follow-up time was 72 months (range 25-143 months). Both the CSF protein concentration and the leukocyte count, if elevated, were significantly, although not independently, associated with diminished probability of event-free survival. The patients were divided into three groups for the final analyses: those without any abnormalities in the CSF (n = 133), those with elevated protein concentration and/or elevated leukocyte count, but with no malignant lymphoblasts in the CSF (n = 21), and those with malignant lymphoblasts in the CSF (n = 6). The probabilities of 5-year event-free survival for the first and second group were 65% and 15%; the probability of 2-year event-free survival for the third group was 17%. These differences were statistically significant (p less than 0.001). In multivariate analysis the relative risks of death or relapse for these groups were 1, 2.8 (95% confidence limits 1.5-4.9), and 7.6 (2.4-24.3), respectively (p less than 0.001). The inclusion of an elevated CSF protein concentration or leukocyte count in the risk group criteria of further trials should be considered.