Analysis of Ki-67 expression in oral squamous cell carcinoma: why Ki-67 is not a prognostic indicator.
OBJECTIVE
To analyze the prognostic value of Ki-67 in oral cancer and its relationship with Ki-67 expression in precancerous epithelium.


METHODS
We studied 79 tumors from 65 patients. Immunohistochemistry study with Mib-1 monoclonal antibody was used to detect Ki-67 expression in tumor tissue and adjacent non-tumor tissue. The influence of different variables on survival was studied with univariate and multivariate analyses.


RESULTS
Ki-67 expression was significantly higher in well-differentiated versus poorly-differentiated carcinomas. The survival time of these patients was affected by the clinical presentation, T, N, stage, and surgical treatment. Ki-67 expression had no impact on survival. An association was found between the parabasal expression of Ki-67 in adjacent non-tumor epithelium and Ki-67 expression in the tumor.


CONCLUSIONS
Ki-67 lacks prognostic value, probably because it is a marker of the total fraction of proliferating cells, corresponding not only to cells in constant proliferation but also to proliferating cells destined for terminal differentiation.
Gonzalez-Moles
M A
MA
Oral Medicine Department, School of Dentistry, University of Granada, Paseo de Cartuja s/n, 18071 Granada, Spain. magonzal@ugr.es <magonzal@ugr.es>
Ruiz-Avila
I
I
Gil-Montoya
J A
JA
Esteban
F
F
Bravo
M
M
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism*; D002294:Carcinoma, Squamous Cell / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D011237:Predictive Value of Tests; D011379:Prognosis; D018809:Proliferating Cell Nuclear Antigen / Q000235:genetics / Q000378:metabolism; D013030:Spain; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism*
D014408:Biomarkers, Tumor; D019394:Ki-67 Antigen; D018809:Proliferating Cell Nuclear Antigen; D016159:Tumor Suppressor Protein p53