Cyclooxygenase-2 expression in borderline ovarian tumors.
OBJECTIVE
The aim of the study was to investigate by immunohistochemistry the expression of cyclooxygenase-2 (COX-2) in a single institutional series of borderline ovarian tumors (BOT). Moreover, to perform a comparative analysis, COX-2 expression was also analyzed in benign and malignant ovarian tumors.


METHODS
Paraffin-embedded sections form 51 BOT, 26 benign, and 37 malignant ovarian tumors were incubated with polyclonal antiserum against COX-2. The results were calculated as the product of the percentage of the immunostained tumor cells by the relative staining score. Cases with immunostaining values of >1 were considered COX-2-positive.


RESULTS
Thirty-four (66.7%) of fifty-one BOT were considered as COX-2-positive, and this rate was not significantly different with respect to COX-2 positivity in benign (50.0%) and in malignant (51.3%) ovarian tumors (P value = 0.23). A significantly higher percentage of COX-2 positivity was found in serous (24 of 24, 100%) with respect to mucinous (9 of 26, 34.6%) BOT (P value = 0.0001). Moreover, 7 (63.6%) of 11 endocervical-type mucinous borderline ovarian tumors were COX-2-positive with respect to only 2 of 15 (13.3%) intestinal-type mucinous BOT (P value = 0.013). The same trend was observed in benign lesions, with COX-2 positivity in 9 of 11 (81.8%) of serous versus 4 of 15 (26.7%) of mucinous tumors (P value = 0.015). On the other hand, no difference was found in the percentage of COX-2 positivity in serous (14 of 29, 48.3%) versus mucinous (5 of 8, 62.5%) ovarian carcinomas (P value = 0.22).


CONCLUSIONS
COX-2 is differently expressed in BOT according to different histotype. Moreover, an increase of COX-2 positivity was observed from mucinous intestinal BOT to frankly malignant ovarian tumors suggesting that COX-2 overexpression might be involved in mucinous ovarian carcinogenesis.
Ferrandina
Gabriella
G
Department of Obstetrics and Gynecology, Catholic University, 00168 Rome, Italy. gabriella.ferrandina@libero.it
Zannoni
Gian F
GF
Ranelletti
Franco O
FO
Legge
Francesco
F
Gessi
Marco
M
Salutari
Vanda
V
Gallotta
Valerio
V
Lauriola
Libero
L
Scambia
Giovanni
G
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D051546:Cyclooxygenase 2; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000096:biosynthesis*; D008565:Membrane Proteins; D008875:Middle Aged; D010051:Ovarian Neoplasms / Q000201:enzymology* / Q000473:pathology; D011451:Prostaglandin-Endoperoxide Synthases / Q000096:biosynthesis*; D012189:Retrospective Studies; D015996:Survival Rate
D007527:Isoenzymes; D008565:Membrane Proteins; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases