Adding the p16(INK4a) marker to the traditional 3-marker (ER/Vim/CEA) panel engenders no supplemental benefit in distinguishing between primary endocervical and endometrial adenocarcinomas in a tissue microarray study

Endocervical adenocarcinomas (ECAs) and endometrial adenocarcinomas (EMAs) are malignancies that affect the uterus; however, their biologic behaviors are quite different. This distinction has clinical significance, because the appropriate therapy may depend on the site of tumor origin. In this study, we not only compare the individual expression status of 4 immunomarkers [estrogen receptor (ER), vimentin (Vim), carcinoembryonic antigen (CEA), and p16 INK4a ], but also evaluate whether p16 INV4a adds value to the ER/Vim/CEA panel characteristics and performance in distinguishing between primary ECA and EMA. A tissue microarray (TMA) was constructed using paraffin-embedded, formalin-fixed tissues from 38 hysterectomy specimens, including 14 ECAs and 24 EMAs. Tissue microarray sections were immunostained with 4 antibodies, by the avidin-biotin complex method for antigen visualization. The staining intensity and area extent of the immunohistochemical reactions were evaluated using the semiquantitative scoring system. The 3 markers (ER, Vim, CEA) and their respective panel expressions showed statistically significant (P