Clinical significance of p27 Kip1 expression in advanced ovarian cancer

ABSTRACT

Background: Ovarian cancer is the most common gynecological malignancy. In patients with advanced ovarian cancer, some biological parameters have prognostic implementations. P27kip1 is an inhibitor of a cycline-dependent kinase, its loss, can contribute to tumor progression. Objective: This study aimed to examine the importance of P27KIP1 protein in predicting the prognosis and response to neoadjuvant chemotherapy in patients with advanced ovarian epithelial cancer and to compare the outcomes of immunohistochemistry with Quantitative Real-time PCR. Patients and methods: We have studied P27KIP1expression by both immunohistochemistry and Quantitative Realtime PCR from 88 patients with advanced ovarian carcinomas undergone radical debulking surgery and received Paclitaxel followed by Cisplatin every 3 weeks for a total of 6 cycles. We also studied their association with both chemotherapy response and patient survival. Results: Nuclear expression of p27KIP1 protein was intense in 86 normal ovarian tissues and 42 of 88 carcinomas. The P27kip1mRNA expression level by qRT-PCR was very low in ovarian cancer tissues relative to its adjacent normal tissues. The results were statistically significant by both methods of determination. p27KIP1 expression was significantly related to good prognostic parameters as low stage tumors, differentiated tumors, absence of ascites, residual disease < 2 cm, and response to chemotherapy but not with histopathological type in case of determination by immunohistochemistry. Comparison of P27kip1 by both immunohistochemistry and qRTPCR with different prognostic parameters revealed no significant difference between both methods in the assessment of these parameters. In 4 years of follow-up, 20.5% of patients were alive without evidence of disease. 6.8% were alive with disease. The disease-related four -year survival rate for the whole group was 28.2%. In multivariate analysis, residual disease, histological type, tumor differentiation, ascites was of independent prognostic significance. Conclusion: In ovarian cancer, patients with loss of p27KIP1 expression are at a greater likelihood of disease progression, p27KIP1 may be used as a molecular marker to predict response to chemotherapy and prognosis. Both immunohistochemistry and qRT-PCR have equal reliability in the determination of p27 KIP1