title: COX-2 expression is associated with an aggressive phenotype in ductal carcinoma in situ.
abstract: Cyclooxygenase type-2 (COX-2) is overexpressed in malignant tumours including breast cancers, though the mechanism of upregulation is unclear. This study aimed to determine COX-2 expression in ductal carcinoma in situ (DCIS) in comparison to invasive breast cancer (IBC) and normal breast, and also to investigate the relationship of COX-2 expression with HER-2 expression, oestrogen receptor (ER), tumour grade and cellular proliferation (Ki67) in DCIS. Cyclooxygenase type-2, HER-2, ER and Ki67 expression were determined by immunohistochemistry on paraffin tissue sections of DCIS (n=187), IBC (n=65) and normal breast reduction tissue (n=60). Cyclooxygenase type-2 expression in DCIS (67%, P<0.001) and IBC (63%, P<0.001) was significantly greater than in normal breast (23%). There was no difference in COX-2 expression level between DCIS and IBC (P=0.87) or between normal breast from reduction mammoplasty tissue and normal breast ducts around DCIS (22%, P=0.29). In DCIS, COX-2 expression was associated with higher cellular proliferation rates (P<0.0001), nuclear grade (P=0.003), with ER negativity (P=0.003) and with HER-2 positivity (P<0.0001). Cyclooxygenase type-2 expression is upregulated in in situ breast cancer and is associated with surrogate markers of an aggressive DCIS phenotype including nonoestrogen-regulated signalling pathways. Cyclooxygenase type-2 inhibition may potentially prevent the development of ER-positive and ER-negative breast cancers.
authors.affiliation: Academic Department of Surgery, University Hospital of South Manchester, Southmoor Road, Manchester M23 9LT, UK.
authors.forename: G P
authors.initials: GP
authors.lastname: Boland
authors.forename: I S
authors.initials: IS
authors.lastname: Butt
authors.forename: R
authors.initials: R
authors.lastname: Prasad
authors.forename: W F
authors.initials: WF
authors.lastname: Knox
authors.forename: N J
authors.initials: NJ
authors.lastname: Bundred
mesh_terms: D000328:Adult; D001943:Breast Neoplasms / Q000201:enzymology / Q000235:genetics* / Q000473:pathology*; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000201:enzymology / Q000235:genetics* / Q000473:pathology*; D002455:Cell Division; D051546:Cyclooxygenase 2; D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors / Q000627:therapeutic use; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007527:Isoenzymes / Q000096:biosynthesis* / Q000494:pharmacology; D008565:Membrane Proteins; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D010641:Phenotype; D011379:Prognosis; D011451:Prostaglandin-Endoperoxide Synthases / Q000096:biosynthesis* / Q000494:pharmacology; D011960:Receptors, Estrogen / Q000032:analysis; D012189:Retrospective Studies; D015398:Signal Transduction; D015854:Up-Regulation
chemical_list: D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors; D007527:Isoenzymes; D008565:Membrane Proteins; D011960:Receptors, Estrogen; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases