Background: Increasing evidence suggests that COX-2 promotes carcinogenesis but it is controversial as to whether COX-2 expression is a prognostic factor for rectal carcinoma.
Materials and methods: Data of 62 consecutive patients with rectal carcinoma in UICC-stages I-III, which were curatively resected between 1995 and 1996, were analyzed. The paraffin-embedded tumor samples were stained for COX-2 expression. A labeling index of stained cells was calculated and the median COX- 2 labeling index was used as the cut-offpoint for statistical analysis.
Results: The median labeling index was 0.58 (SD +/- 0.25). The Chi-square test revealed no correlation between COX-2 overexpression and the established prognostic factors. In the univariate analysis, COX-2 did not show significance according to the endpoints, local recurrence (p=0.41), disease-specific survival (p=0.28) or overall-survival (p=0.69). In contrast increased COX-2 level was a significant prognostic factor for pulmonary metastasis (p=0.04).
Discussion: COX-2 expression lacked significance as a prognostic factor for local control and survivaL However, there is evidence that COX-2 might be linked to an increased risk of hematogenous metastatic spread.