[Pathobiologic aspects of the limited extracranial metastasis capability of tumors of the central nervous system].
Primary tumors of the central nervous system (CNS) very rarely metastasize to other parts of the body, both in animals and in man, irrespective of survival time. The only exception to this rule is observed in meningiomas in man with a metastasis incidence of 18.7%. Experimental studies have provided strong evidence for an important modulating role of the extracellular matrix upon the invasion capacity of tumors. Malignant progression of tumors depends upon accumulation of somatic mutations which impart a selective advantage for invasion into the surrounding connective stroma. Such mutations seem to result from an active confrontation and interaction between tumor cells and components of the stroma. As the parenchyma of the CNS is largely free of connective tissue no such selection interplay occurs in genuine CNS tumors, in contrast to tumors of the other parts of the body with an abundance of connective tissue surrounding them. This explains the rarity of extracranial metastases of CNS tumors. In contrast, other tumors of the body metastasize more frequently into the CNS. Obviously, this potency is correlated with the frequency of mutations at the CD44 gene locus.
Schmahl
W
W
Institut für Pathologie, GSF-Forschungszentrum für Umwelt und Gesundheit, Oberschleissheim.
D000818:Animals; D002352:Carrier Proteins / Q000235:genetics; D016543:Central Nervous System Neoplasms / Q000235:genetics / Q000473:pathology*; D006801:Humans; D018960:Hyaluronan Receptors; D009154:Mutation; D009362:Neoplasm Metastasis / Q000473:pathology*; D011956:Receptors, Cell Surface / Q000235:genetics; D016201:Receptors, Lymphocyte Homing / Q000235:genetics
D002352:Carrier Proteins; D018960:Hyaluronan Receptors; D011956:Receptors, Cell Surface; D016201:Receptors, Lymphocyte Homing