PTGS2 (Cyclooxygenase-2) Expression and Survival amongst Colorectal Cancer Patients: A Systematic Review
A partir d'une revue systématique de la littérature publiée jusqu'en décembre 2011 (29 études, 5 648 patients), cette étude évalue l'association entre l'expression tumorale de la cyclo-oxygénase-2 et la survie des patients atteints d'un cancer colorectal
Background : Studies have examined whether tumour expression of PTGS2 (also known as cyclooxygenase-2), an enzyme inhibited by non-steroidal anti-inflammatory drugs (NSAIDs) such as aspirin, is associated with prognosis in colorectal cancer patients. However, results to date have been mixed.
Methods : Using terms for PTGS2 and colorectal cancer, the Medline, Embase and Web of Science databases were systematically searched for studies published, in any language, until December 2011. Random effects meta-analyses were used to calculate pooled Hazard Ratios (HR) (95%Confidence intervals (CI)) for the association between PTGS2 expression and tumour recurrence, colorectal cancer-specific survival and overall survival.
Results : In total, 29 studies, which had prognostic data on 5 648 patients, met the inclusion criteria. PTGS2 positive patients were at an increased risk of tumour recurrence (n=9 studies; HR 2.79; 95%CI 1.76-4.41, p<0.001), and had poorer colorectal cancer-specific survival (n=7; HR 1.36; 95%CI 1.02-1.82, p=0.04). However, there was funnel plot asymmetry, possibly due to publication bias, for the association with cancer-specific survival but less so for recurrence. PTGS2 expression was not associated with overall survival (n= 16; pooled unadjusted HR 1.30; 95%CI 0.94-1.79, p=0.11) and (n=9; pooled adjusted HR=1.02; 95%CI 0.72-1.45, p=0.91).
Conclusions : PTGS2 expression was associated with an increased risk of tumour recurrence and poorer colorectal cancer-specific survival but not overall survival amongst colorectal cancer patients. However, confounding by tumour characteristics, such as tumour stage, seems likely.
Impact : There is insufficient evidence to recommend PTGS2 expression as a prognostic marker in colorectal cancer patients. Further studies providing adjusted results are required.
Cancer Epidemiology Biomarkers & Prevention , résumé, 2013