Cyclin E Expression in Operable Breast Cancer Quantified Using Real-Time RT–PCR: A Comparative Study with Immunostaining

Objective: The main purpose of this retrospective study was to compare cyclin E expression levels in operable breast cancer patients determined using real-time RT–PCR and immuno-staining. The prognostic relevance of cyclin E was also investigated. Methods: Specimens of invasive ductal breast cancer tissues obtained from 124 women during radical mastectomy were analyzed. Results:Of the tumor samples, 40.3 and 59.7 % showed high expression of cyclin E in RT–PCR and immunostaining, respectively. The overall agreement probability was 0.032 according to Scott’s p statistic. With a median follow-up of 55.5 months, cyclin E expression assessed using immunostaining was an independent negative prognostic factor in the node positive group (hazard ratio 3.1; 95%CI 1.0–9.2;P = 0.045). Cyclin E expression correlatedwith absence of steroid receptors and younger age. RT–PCR results did not predict survival in any group of patients. Conclusions: Disagreement between real-time RT–PCR and immunostaining was demon-strated. Immunostaining seems to be the more reliable method for assessing cyclin E in breast cancer cells. Key words: breast neoplasms – cyclin E – immunochemistry – prognosis – reverse transcription PC