title: [On the growth characteristics of human osseous sarcoma metastases: mathematical calculations and clinical consequences (author's transl)].
abstract: Metastases of osteosarcomas do not grow according to a simple exponential function, but rather according to a type of Gompertz' function where flattening with a tendency toward plateau formation sets in after a certain time. This deviation from an exponential growth type corresponds to a substantial increase in the initial tumor size--doubling time. The metastasis doubles in the period after its transfer faster than when it first becomes visible in an x-ray. Another important conclusion resulting from the use of the Gompertz model is the assumption of a tumor-specific maximum volume which cannot be exceeded over a period of infinite growth. For lung metastases of osteosarcoma this volume amounts to approximately 120 cm3. The critical volume which kills the host is, at 70 to 80 cm3, relatively close to this theoretical growth limit (only approximately one cell division below this limit). If a metastasis develops from a single cell, the number of divisions up to this point is approximately 46. Of these, 38 lie within the growth zone which is not visible via x-ray. Since cell-cycle specific agents (for example Vincristin and Methotrexate) have the greatest effect against rapidly proliferating tumors, these drugs (for example alkylantic drugs) are especially effective in the case of slowly proliferating neoplasms. Therefore, use of these drugs should be favored when the metastasis is visible in the x-ray. Since occasionally, particular when the primary tumor is still relatively small, metastasization may not necessarily have already taken place, radical operation of the primary tumor should be carried out as soon as possible. A preliminary irradiation of the primary tumor cannot prevent metastasization with certainty. Therefore delayed amputation should be avoided.
mesh_terms: D001859:Bone Neoplasms / Q000503:physiopathology*; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008940:Mitotic Index; D008954:Models, Biological; D009361:Neoplasm Invasiveness; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D012516:Osteosarcoma / Q000000981:diagnostic imaging / Q000503:physiopathology*; D011859:Radiography
vernacular_title: Zur Wachstumscharakteristik menschlicher Knochensarkom-metastasen: Mathematische Berechnungen und klinische Konsequenzen.