Detection of bcl-2 and p53 in thymoma: expression of bcl-2 as a reliable marker of tumor aggressiveness.
The distinction between noninvasive and invasive or malignant thymoma has been severely compromised by a lack of objective morphological criteria. A reliable marker of tumor aggressiveness is, therefore, mandatory for predicting the tumor behavior. Forty thymic epithelial tumors, including 5 noninvasive thymomas, 18 invasive thymomas, and 17 thymic carcinomas (Rosai's classification) were investigated for expression of bcl-2 and p53 proteins by immunohistochemistry. The thymic epithelial cells showed positive immunostain for bcl-2 in 0, 7, and 16 of these categories, respectively. Thymic carcinomas had a significantly higher proportion of bcl-2 expression than thymomas (P < .0001). A significantly higher expression of bcl-2 protein was also shown in thymoma-associated myasthenia gravis (P < .05). However, p53 showed no correlation with the histological subtypes nor clinical aggressiveness. Bcl-2 expression appeared to be positively correlated with p53 immunoreactivity, but this result was not statistically significant (P = .07). In conclusion, these data indicate that bcl-2 expression correlates with aggressiveness in thymic epithelial neoplasms.
Department of Pathology, National Cheng Kung University Medical Center, Tainan, Taiwan.
F F
FF
Chen
J J
JJ
Yan
Y T
YT
Jin
I J
IJ
Su
D014408:Biomarkers, Tumor / Q000032:analysis*; D002675:Child, Preschool; D006801:Humans; D007150:Immunohistochemistry; D009361:Neoplasm Invasiveness; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000032:analysis*; D013945:Thymoma / Q000737:chemistry* / Q000473:pathology*; D013953:Thymus Neoplasms / Q000737:chemistry* / Q000473:pathology*; D016159:Tumor Suppressor Protein p53 / Q000032:analysis*
D014408:Biomarkers, Tumor; D019253:Proto-Oncogene Proteins c-bcl-2; D016159:Tumor Suppressor Protein p53