Purchase this article with an account.
P.M. Ozdal, S.A. Callejo, A.L. Caissie, S. Bakalian, M.N. Burnier Jr.; Cyclooxygenase-2 Expression in Human Irradiated Uveal Melanomas . Invest. Ophthalmol. Vis. Sci. 2003;44(13):1567.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose: Cyclooxygenase-2 (COX-2) is upregulated in a high percentage of human cancers and is associated with invasive and metastatic tumor behavior. Recently, it has been shown that COX-2 is expressed in 57% of uveal melanomas. Some studies have shown that radiotherapy is a stimulus for COX-2 expression. Plaque radiotherapy is an effective method of controlling the growth of uveal melanomas. However, tumor regrowth or severe complications secondary to radiotherapy may necessitate enucleation of the affected eye. This study is being conducted to evaluate the correlation between COX-2 expression and tumor regrowth following irradiation, in enucleated eyes with uveal melanoma. Methods: Fifteen formalin-fixed and paraffin-embedded tissue samples from patients who underwent enucleation following radiotherapy between 1988 and 2001 were used. Nine cases were enucleated due to tumor regrowth and 6 cases due to severe complications of radiotherapy. Specimens were immunostained for COX-2 and tumor cells were evaluated for specific cytoplasmic immunostaining. COX-2 expression was correlated with tumor regrowth following radiotherapy. Eyes enucleated due to radiotherapy complications served as controls. Results: Of the 15 cases, 2 (13.3%) were positive and 13 (86.7%) were negative for COX-2 expression. One of the COX-2 positive cases had tumor regrowth and the other one had complications due to radiotherapy. There was no relationship with tumor regrowth and COX-2 expression (p>0.5). Conclusions: Although an increase of COX-2 expression has been shown in other irradiated malignancies, irradiation is a factor that decreases COX-2 expression in uveal melanomas. The level of COX-2 expression was not different between irradiated cases enucleated for either tumor regrowth or treatment complications. COX-2 expression is significantly lower in this study of irradiated cases compared to the reported incidence of COX-2 in non-irradiated cases. These results support the efficacy of plaque radiotherapy in uveal melanoma and suggest that tumor regrowth after radiotherapy may be due to factors other than COX-2 expression.
This PDF is available to Subscribers Only