PLA2 (group IIA phospholipase A2) as a prognostic determinant in stage II colorectal carcinoma

Patients and methods: The present study comprises a series of 116 patients who underwent bowel resection for stage II CRC during 1981-1990 at Turku University Hospital. Archival paraffin-embedded CRC tissue samples were used to prepare tissue microarray blocks for immunohistochemical staining with PLA2. Results: Fifty-five percent of all tumors were positive for PLA2. There was no significant correlation between PLA2 expression and age, sex, depth of invasion and lymph node status. In Kaplan-Meier survival analysis, there was a significant (P = 0.010) difference in disease-free survival (DFS) between patients with negative tumors (longer DFS) and those with positive tumors. The same was true with disease-specific survival (DSS), patients with PLA2-negative tumors living significantly longer (P = 0.025). In multivariate (Cox) survival analysis, however, PLA2 was not an independent predictor of DFS or DSS. In subgroup analysis, the right-sided tumors with negative PLA2 staining had remarkably better prognosis (P = 0.010) than PLA2-positive left-sided tumors. Conclusions: Quantification of PLA2 expression seems to provide valuable prognostic information in stage II CRC, particularly in selecting the patients at high risk for recurrent disease who might benefit from adjuvant therapy.