[TNM classification of bone and soft tissue sarcomas].
TNM classification of bone and soft tissue sarcomas was published by UICC in 1987. Histological grading (G) is an important factor in this classification, but the criteria of G categories are not so clear. In addition, lymph node metastasis is very rare in bone and soft tissue sarcoma. Therefore, prognostic factors are limited to T, M and G categories. Since correlation between the stage (UICC) and the survival rate was not found in patients with osteosarcoma, TNM classification (UICC) has not been used widely in the field of orthopedic oncology. The Musculoskeletal Tumor Committee of the Japanese Orthopaedic Association proposed another TNM classification of osteosarcoma based on multivariate analysis. T1 is less than 15 cm and T2 is 15 cm or larger in maximal diameter. N and M are same with the UICC criteria. Serum alkaline phosphatase level (A) is included in this classification in which A0 is less than the normal value x2.5, and A1 is the normal value x2.5 or more. G categories are separated into two groups according to the mitotic rate in a high power field (x200); G1 is assigned to the tumor with 0-9/1 HPF and G2 is assigned to those with 10 or more/1 HPF. Reclassification of osteosar-coma by this modified TNM system indicated that there was a correlation between the survival rate and the stage.
Fukuma
H
H
Dept. of Orthopedic Surgery, National Cancer Center Hospital, Tokyo, Japan.
Beppu
Y
Y
Yokoyama
R
R
Omiya
K
K
D001859:Bone Neoplasms / Q000145:classification* / Q000473:pathology; D006801:Humans; D008207:Lymphatic Metastasis; D012516:Osteosarcoma / Q000145:classification / Q000473:pathology / Q000556:secondary; D012509:Sarcoma / Q000145:classification* / Q000473:pathology / Q000556:secondary; D012983:Soft Tissue Neoplasms / Q000145:classification* / Q000473:pathology