Immunohistochemical Detection of p53 Gene Mutation in Urine Samples in the Patients with Bladder Cancer / 대한세포병리학회지

Although bladder cancers are very common, little is known about their molecular pathogenesis. It is known, that p53 alteration is found in about 60%p of muscleinvasive bladder cancer, necessiating aggressive therapy and poor outcome. We examined the nuclear expression of p53 protein, using D07 monoclonal antibody in the urine samples, from 31 patients with transitional cell carcinoma of the bladder to investigate the correlation of p53 overexpression with histologic grades and depth of invasion. The positive rate of p53 protein was 27%o in superficial bladder tumor, but increased up to 71% in the invasive bladder carcinomas. The overexpression of p53 protein increased according to Mostofi grading system from 18% in grade I, 45% in grade Il, and up to 100% in grade ill. The p53 expression tended to be higher in the invasive and high grade bladder cancers than in the superficial and low grade ones(p<0.05). These results suggest that immunohistochemical analysis of the urine specimen in the bladder cancer patients could be a useful method of screening for the presence of p53 mutant protein. The mutant p53 protein expression may be an indicator of bladder cancer with more proliferative potential and/or aggressive biologic behavior.

Diagnostic Application of p53 IMMUNOSTAINING in Bronchial Brush Specimens / 대한세포병리학회지

Abnormalities of p53 gene are common in lung cancers and are associated with immunologically detectable p53 protein. p53 immunoreactivity is uncommon in normal cells but is frequently seen in neoplasia. Therefore, assessment of p53 expression may assist in the cytological diagnosis of malignancy. The usefulness of p53 immunostaining as a marker of malignancy in the cytological analysis of bronchial brush specimens from the patients with lung cancers was investigated in this study. A total of 71 bronchial brush samples submitted for cytologic diagnosis were immunostained with D07, a monoclonal antibody to recombinant p53 protein. Resultant p53 data were correlated with cytologic diagnosis and clinical information. Of the 17 smears with a benign cytodiagnosis, all were p53 negative. Of the 40 cases with a malignant cytodiagnosis(histologically confirmed), 35 were p53 positive and 5 were negative. Of the 14 cases that were cytologically suspicious but nondiagnostic for malignancy, 11 were p53 positive, 9 of which were subsequently proved to be malignant by histologic examination, and the remaining 2 cases were tuberculosis clinically. Forty four of 51 histologically confirmed lung carcinomas were p53 positive, including 25 of 28 squamous cell carcinomas, 13 of 17 small cell carcinomas, 3 of 3 adeno- carcinomas, and 3 of 3 large cell undifferentiated carcinomas. These results suggest that p53 immunostaining could be of value as a marker of malignancy in the cytologic examination of bronchial brush specimens. Furthermore, we have shown the possible clinical utility of p53 immunostaining in cytopathological diagnosis, that is, as a valuable adjunct to morphological assessment in the analysis of cytopathologically suspicious cases.