Expressão da Ciclo-oxigenase-2 e do Ki67 em tumores borderline serosos e mucinosos de ovario / Cyclooxygenase-2 (COX-22) and Ki67 expression in serous and mucinous ovarian borderline tumors

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

Background: borderline serous and mucinous ovarian tumors form a special group of neoplasia, which differs from benign and malignant tumors of the same histological category. Molecular markers are currently providing information on the biological characteristics and clinical behavior of the ovarian tumors; among them, borderline tumors. Cyclooxygenase-2 (COX-2), an enzyme linked to the inflammation process, is known to correlate with carcinogenesis. On the other hand, the Ki67, a marker of cell proliferation, is capable of identifying abnormalities of the cell-cycle control system and apoptosis. Objective: to compare the expression of COX-2 in serous and mucinous borderline ovarian tumors and to evaluate whether this expression is related to cell proliferative activity, by its turn assessed with the expression of Ki67, to the presence of peritoneal implants and to the disease stage. Subjects and methods: for this cross-sectional descriptive study we selected paraffin blocks from women with borderline ovarian tumors, treated at the State University of Campinas, São Paulo, and at The National Institute of Cancer, Rio de Janeiro, Brazil, between January 1998 and December 2004. After revision of the medical records, women that were pregnant at the moment of diagnosis, that harbored other malignancies or that were using nonsteroidal antinflammatory drugs were excluded. All slides were reviewed by two pathologists and 86 blocks were selected to undergo immunohistochemical evaluation. The tumors that were included were categorized as: serous (36), mucinous (46) and seromucinous (4). The cytoplasmatic expression of COX-2 and the nuclear expression of Ki67 were determined with immunohistochemistry in slides obtained from these borderline tumor paraffin blocks. Results: the mean age of the women was 42.4 years (standard deviation 16.5), and there was no significant difference between the mean ages of women with serous, mucinous or seromucinous tumors (p=0.62). Seventy-one women had stage I disease and only three had stage II disease. Of the thirteen women with peritoneal implants, seven had serous borderline tumors, three had mucinous and three seromucinous tumors. The proportion of women with peritoneal implants and stage III disease was significantly higher among women with seromucinous tumors (p=0.0001). The nuclear expression of Ki67 was higher in mucinous tumors (65.8%) in comparison to serous (25%) and seromucinous (25%) (p=0.001). After multivariate analysis it was observed that the cytoplasmatic expression of COX- 2 was significantly higher in serous tumors compared to mucinous (68.5% vs 52.5%; p<0.01). There were no differences regarding the expression of COX-2 comparing seromucinous versus mucinous and mucinous versus seromucinous. The higher cytoplasmatic expression of COX-2 was significantly associated with an increased expression of Ki67 in all histological types (p=0.03). On the other hand, the expression of COX-2 was not related to disease stage and peritoneal implants. Conclusions: these results indicate that the expression of COX-2 is higher in serous borderline ovarian tumors compared to mucinous ones. They also indicate that COX-2 is a good predictor of cell proliferation because its expression increases in parallel to that of Ki67. However, this study does not allow concluding whether COX-2 is a modulator of the tumor´s behavior or just a marker of other biological events, considering that it bore no relation to disease stage or peritoneal implants

ASSUNTO(S)

ovary bordeline ovarian tumor ovarios - cancer ovary ovarios tumos borderline de ovario

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