title: Cyclooxygenase-2 expression in primary and metastatic Merkel cell carcinoma.
abstract: Cyclooxygenase-2 (COX-2) is involved in the development and progression of many tumors, and its inhibition has been shown to block tumor growth. This study examined COX-2 expression in primary and metastatic Merkel cell carcinoma (MCC). Formalin-fixed paraffin-embedded tissues from 26 primary MCCs and 7 lymph node metastases were stained immunohistochemically with a monoclonal antibody directed against COX-2, and the percentage and intensity of staining were analyzed semiquantitatively. Immunopositivity for COX-2 was found in 20 primary tumors (77%), and was diffuse in 16 of them (80%). Staining intensity was strong in 5 tumors (19%), moderate in 6 (23%), and weak in 9 (35%). Five metastases (71%) showed similar staining. Prominent mitotic activity was associated with more diffuse COX-2 immunopositivity. No association was found between COX-2 expression and outcome. This study confirms that most MCCs express COX-2 and shows that COX-2 expression is related to one parameter of aggressive behavior--a high mitotic rate--but not to any others. The possibility of treating MCC with COX-2 inhibitors should be considered.
authors.affiliation: Department of Otolaryngology, Rabin Medical Center, Beilinson Hospital, Petah Tiqwa, Israel.
authors.forename: Zohar
authors.initials: Z
authors.lastname: Joachims
authors.forename: Raphael
authors.initials: R
authors.lastname: Feinmesser
authors.forename: Ofer
authors.initials: O
authors.lastname: Purim
authors.forename: Marisa
authors.initials: M
authors.lastname: Halpern
authors.forename: Baruch
authors.initials: B
authors.lastname: Brenner
authors.forename: Eyal
authors.initials: E
authors.lastname: Fenig
authors.forename: Pepi
authors.initials: P
authors.lastname: Roizman
authors.forename: Jaqueline
authors.initials: J
authors.lastname: Sulkes
authors.forename: Meora
authors.initials: M
authors.lastname: Feinmesser
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000911:Antibodies, Monoclonal; D015266:Carcinoma, Merkel Cell / Q000201:enzymology* / Q000473:pathology / Q000556:secondary*; D051546:Cyclooxygenase 2 / Q000096:biosynthesis* / Q000235:genetics* / Q000276:immunology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008938:Mitosis / Q000235:genetics / Q000276:immunology; D009361:Neoplasm Invasiveness; D012878:Skin Neoplasms / Q000201:enzymology* / Q000473:pathology*
chemical_list: D000911:Antibodies, Monoclonal; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human