Reassessment of the 1993 Osaka grading system for localized soft tissue sarcoma in Japan.
BACKGROUND
The Osaka system for soft-tissue sarcoma grading was proposed through an analysis of soft-tissue sarcoma (STS), treated from 1964 to 1989. The present study was conducted to evaluate the utility of the Osaka system under recent therapeutic regimens.


METHODS
One hundred and eleven patients with localized STSs arising in the trunk and extremities (66 males and 45 females; median age 57) were selected. Histological factors, argyrophilic nucleolar organizer region (AgNOR) count and Ki-67 labeling index (LI) were evaluated for prognostic significance.


RESULTS
Univariate analysis revealed that histological classification, mitotic count, cellularity, AgNOR count, and Ki-67 LI were prognostically significant for survival. Multivariate analysis revealed Ki-67 LI as an independent prognostic factor. The five-year survival rate for low-, intermediate-, and high-grade STSs in Osaka grading was 94.6%, 75.2%, and 68.4%, respectively.


CONCLUSIONS
Osaka grading is a useful system for the decision-making of therapeutic modalities for STS.
Tomita
Yasuhiko
Y
Department of Pathology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan. yt@molpath.med.osaka-u.ac.jp
Morooka
Takaya
T
Hoshida
Yoshihiko
Y
Zhang
Binglin
B
Qiu
Ying
Y
Nakamichi
Itsuko
I
Hamada
Kenichiro
K
Ueda
Takafumi
T
Naka
Norifumi
N
Kudawara
Ikuo
I
Aozasa
Katsuyuki
K
D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011379:Prognosis; D012509:Sarcoma / Q000473:pathology*; D012720:Severity of Illness Index