title: The role of COX-2 in rectal cancer treated with preoperative radiotherapy.
abstract: Radiotherapy is one of the principal modalities of rectal cancer treatment, and the ability to predict radio resistance could potentially improve survival through a targeted treatment approach. Cyclooxygenase-2 (COX-2) may protect against damage by irradiation that would justify the use of COX-2 inhibitors. The purpose of this study was to investigate the potential role of COX-2 in tumor response and outcome of patients with rectal cancer treated preoperatively with radiotherapy. Using immunohistochemistry, we examined COX-2 expression in 88 surgical specimens of rectal cancer treated preoperatively and in 26 pretherapeutic biopsies. We tested whether COX-2 expression was correlated with clinico-pathologic parameters and with survival and local recurrence. COX-2 was expressed in 50% of the pretherapeutic tumor biopsies and in 88.6% of post-irradiated surgical samples. COX-2 expression was correlated only with enhanced tumor inflammation (p = 0.03) and with tumor volume exceeding 30 cc (p = 0.05). COX-2 was not significantly correlated with patient survival, but none of the patients with COX-2 negative tumors did recur locally, whereas 80% of patients with local recurrences have COX-2 positive tumors. We conclude that COX-2 expression is overexpressed in the majority of rectal cancers treated with radiotherapy and likely plays a role in local relapse.
authors.affiliation: Institute of Pathology, Centre Hospitalier Universitaire Vaudois, Bugnon 25, CH 1011 Lausanne, Switzerland. Hanifa.Bouzourene@chuv.ch
authors.forename: Hanifa
authors.initials: H
authors.lastname: Bouzourene
authors.forename: Pu
authors.initials: P
authors.lastname: Yan
authors.forename: Dominique
authors.initials: D
authors.lastname: Sandmeier
authors.forename: Abderrahim
authors.initials: A
authors.lastname: Zouhair
authors.forename: Maurice
authors.initials: M
authors.lastname: Matter
authors.forename: Henri
authors.initials: H
authors.lastname: Vuilleumier
authors.forename: Philippe
authors.initials: P
authors.lastname: Coucke
mesh_terms: D000230:Adenocarcinoma / Q000201:enzymology* / Q000473:pathology / Q000532:radiotherapy*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D051546:Cyclooxygenase 2 / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000517:prevention & control; D011300:Preoperative Care; D011379:Prognosis; D012004:Rectal Neoplasms / Q000201:enzymology* / Q000473:pathology / Q000532:radiotherapy*; D012189:Retrospective Studies; D016019:Survival Analysis; D016896:Treatment Outcome
chemical_list: D051546:Cyclooxygenase 2