[1075] Immunohistochemical Features of Post-Radiation Recurrences of Endometrioid Carcinomas of the Endometrium

M Santacana, J Pallares, S Lopez, A Yeramian, X Dolcet, E Oliva, X Matias-Guiu. Hospital U Arnau de Vilanova, Lleida, Spain; Massachusetts General Hospital, Boston, MA

Background: Endometrioid carcinoma of the endometrium (EC) is typically treated with surgery and radiotherapy. Post-radiation recurrences of EC are usually associated with increased risk of metastases. Even though the molecular alterations involved in post-radiation recurrences of EC have not been evaluated, alterations of genes responsible for the extrinsic and intrinsic apoptosis pathways, like p53 and NF-kb, have been involved in resistance to radiotherapy in other types of tumor.
Design: Ten post-radiation recurrences of EC were evaluated by immunohistochemistry (IHC) compared to a group of 95 primary EC. The IHC panel included estrogen (ER) and progesterone receptors (PR), p53, Ki 67, E-cadherin, beta-catenin, PTEN, HIF-alpha, CK2, FLIP, BAX, Bcl-xL, MLH-1, MSH-2, MSH-6, and members of the NF-kb family of genes.
Results: Overall, post-radiation recurrences showed decreased expression of ER and PR, and increased expression of p53 in comparison with primary EC. Interestingly, the vast majority of the recurrences exhibited beta-catenin nuclear expression, which is detected in 30% of the primary EC. Moreover, postradiation recurrences showed frequent nuclear expression for members of the NF-kb family of genes (c-Rel, p52).
Conclusions: The results suggest that alterations of genes involved in the control of apoptosis may play a role in resistance to radiation in EC. Moreover, nuclear expression of beta-catenin, which is regarded as a feature of indolent behaviour in EC is also frequent in post-radiation recurrences of EC, suggesting that beta-catenin can also play a role in resistance to radiation.
Category: Gynecologic

Wednesday, March 11, 2009 1:00 PM

Poster Session VI # 153, Wednesday Afternoon