Suprabasal p53 immunoexpression is strongly associated with high grade dysplasia and risk for malignant transformation in potentially malignant oral lesions from Northern Ireland.
OBJECTIVE
No good predictive marker for the malignant transformation of potentially malignant oral lesions (PMOLs) is currently available. This study re-evaluated the value of p53 immunoexpression to predict malignant transformation of PMOLs after discounting possible confounding factors.


METHODS
PMOLs from 18 patients who showed progression to carcinoma, 16 of the respective carcinomas, and PMOLs from 18 matched controls were evaluated by immunohistochemistry (IHC) for p53 expression. A mouse monoclonal antibody that detects wild-type and mutant forms of human p53 was used. The p53 immunostaining pattern was also correlated with the degree of dysplasia.


RESULTS
Suprabasal p53 staining was significantly associated with high grades of dysplasia (p < 0.01). The specificity and positive predictive value (PPV) for malignant transformation of suprabasal p53 staining were superior to the assessment of dysplasia, but sensitivity was inferior. All carcinomas derived from PMOLs with suprabasal p53 showed strong p53 immunostaining. However, the absence of suprabasal p53 staining and/or dysplastic changes did not preclude malignant transformation in a considerable proportion of PMOLs.


CONCLUSIONS
This study confirms and extends previous findings that suprabasal p53 immunoexpression has a high PPV for malignant transformation of PMOLs and can be used as a specific marker for lesions that are at high risk for malignant transformation. The absence of suprabasal p53 staining (that is, absence of, or basal, p53 staining) is non-informative for prognostic purposes. Because of its limited sensitivity, p53 IHC is not a substitute for the assessment of dysplasia in the evaluation of PMOLs. Instead, p53 IHC emerges as a clinically useful supplement of histopathological assessment in the prognosis of PMOLs.
Cruz
I
I
Department of Oral and Maxillofacial Surgery/Oral Pathology, Academic Centre for Dentistry Amsterdam, University Hospital Vrije Universiteit, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands. geus@xs4all.nl
Napier
S S
SS
van der Waal
I
I
Snijders
P J F
PJ
Walboomers
J M M
JM
Lamey
P J
PJ
Cowan
C G
CG
Gregg
T A
TA
Maxwell
P
P
Meijer
C J L M
CJ
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000378:metabolism*; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007124:Immunoenzyme Techniques; D007972:Leukoplakia, Oral / Q000378:metabolism / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000378:metabolism* / Q000473:pathology; D011230:Precancerous Conditions / Q000378:metabolism* / Q000473:pathology; D011237:Predictive Value of Tests; D011379:Prognosis; D012680:Sensitivity and Specificity; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*
D014408:Biomarkers, Tumor; D016159:Tumor Suppressor Protein p53