Ki-67 expression is predictive of prognosis in patients with stage I/II extranodal NK/T-cell lymphoma, nasal type.
BACKGROUND
Localized extranodal natural killer (NK)/T-cell lymphoma, nasal type, commonly has a low or low-intermediate risk of the international prognostic index (IPI), so the IPI has shown inconsistency in predicting prognosis. Thus, we analyzed Ki-67 expression and proposed a new prognostic model including Ki-67 expression for stage I/II extranodal NK/T-cell lymphoma.


METHODS
We studied Ki-67 expression and its relationship with prognosis in 50 patients with extranodal NK/T-cell lymphoma.


RESULTS
The patients were dichotomized by the median value: low (<65%) versus high Ki-67 (> or =65%). High Ki-67 was associated with a worse overall survival (OS; P = 0.021) and disease-free survival (DFS; P = 0.044). In multivariate analysis, Ki-67 expression and primary site of involvement were found to be an independent prognostic factor for OS and DFS (P < 0.05). Based on these results, we proposed a new clinico-pathological prognostic model with Ki-67 expression and the primary site of involvement. It showed a high degree of correlation with worse OS and DFS (P < 0.001).


CONCLUSIONS
Ki-67 expression is predictive of prognosis, and our prognostic model may become a useful tool for predicting prognosis in patients with stage I/II extranodal NK/T-cell lymphoma, nasal type.
Kim
S J
SJ
Department of Internal Medicine, Korea University Medical Center, Seoul, Korea.
Kim
B S
BS
Choi
C W
CW
Choi
J
J
Kim
I
I
Lee
Y-H
YH
Kim
J S
JS
D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use; D003131:Combined Modality Therapy; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D053208:Kaplan-Meier Estimate; D019394:Ki-67 Antigen / Q000096:biosynthesis*; D054391:Lymphoma, Extranodal NK-T-Cell / Q000378:metabolism* / Q000401:mortality* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D009669:Nose Neoplasms / Q000378:metabolism* / Q000401:mortality* / Q000628:therapy; D011379:Prognosis; D011878:Radiotherapy
D000970:Antineoplastic Agents; D019394:Ki-67 Antigen