Low expression of p27(Kip1), a cyclin-dependent kinase inhibitor, is a marker of poor prognosis in synovial sarcoma.
BACKGROUND
Low expression of p27(kip1), a dominant cyclin-dependent kinase inhibitor involved in G1-S transition of the cell cycle, recently has been reported to be associated with aggressive tumor growth. It has been shown that active cell proliferation alludes to poor prognosis in patients with synovial sarcoma. However, to the authors' knowledge, little is known about the clinicopathologic significance of p27(kip1) in synovial sarcoma.


METHODS
p27(kip1) expression was examined immunohistochemically in 55 cases of primary synovial sarcoma, and the relations between p27(kip1) expression and several cell proliferation markers, i.e., mitotic index (MI), Ki-67 labeling index (Ki-67 LI), and clinicopathologic parameters related to poor prognosis, were determined. Univariate and multivariate survival analyses were performed to evaluate the prognostic significance of p27(kip1) expression in synovial sarcomas.


RESULTS
p27(kip1) labeling index (p27(kip1) LI) correlated inversely with MI (r = -0.44, P = 0.0007) and Ki-67 LI (r = -0.63, P < 0.0001). Of the clinicopathologic parameters examined, tumor necrosis (P = 0.019) and American Joint Committee on Cancer (AJCC) stage (P = 0.021) correlated significantly with p27(kip1) LI. Survival analysis showed that p27(kip1) LI was an independent prognostic factor for overall survival in patients with synovial sarcoma (P = 0.0031).


CONCLUSIONS
The study results suggested that low expression of p27(kip1) may be useful as a marker of poor-prognosis synovial sarcoma.
Department of Pathology, Yamaguchi University School of Medicine, Yamaguchi, Japan. 2byouri@po.cc.yamaguchi-u.ac.jp
S
S
Kawauchi
Y
Y
Goto
X P
XP
Liu
T
T
Furuya
A
A
Oga
Y
Y
Oda
M
M
Tsuneyoshi
K
K
Ihara
K
K
Sasaki
D000293:Adolescent; D000328:Adult; D000368:Aged; D002453:Cell Cycle; D018797:Cell Cycle Proteins; D002648:Child; D050760:Cyclin-Dependent Kinase Inhibitor p27; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008297:Male; D008869:Microtubule-Associated Proteins / Q000032:analysis / Q000096:biosynthesis*; D008875:Middle Aged; D008940:Mitotic Index; D011379:Prognosis; D013584:Sarcoma, Synovial / Q000235:genetics* / Q000473:pathology*; D012983:Soft Tissue Neoplasms / Q000235:genetics* / Q000473:pathology*; D016019:Survival Analysis; D025521:Tumor Suppressor Proteins
D018797:Cell Cycle Proteins; D008869:Microtubule-Associated Proteins; D025521:Tumor Suppressor Proteins; D050760:Cyclin-Dependent Kinase Inhibitor p27