1. ¹Department of Oncology, Helsinki University Central Hospital, PO Box 180, 00029 HUS Helsinki, Finland
2. ²Department of Genetics and Pathology, Uppsala University Hospital, Uppsala, Sweden
3. ³Department of Oncology, Medical Centre Hospital, Örebro, Sweden
4. ⁴Department of Oncology, Gävle Hospital and Clinical Research Centre, County of Gävleborg, Gävleborg, Sweden

Correspondence: Dr P Poikonen, E-mail: Paula.Poikonen@hus.fi

Revised 31 May 2005; Accepted 6 July 2005; Published online 9 August 2005.

Abstract

We wanted to study cyclin A as a marker for prognosis and chemotherapy response. A total of 283 women with metastatic breast cancer were initially enrolled in a randomised multicentre trial comparing docetaxel to sequential methotrexate-fluorouracil (MF) in advanced breast cancer after anthracycline failure. Paraffin-embedded blocks of the primary tumour were available for 96 patients (34%). The proportion of cells expressing cyclin A was determined by immunohistochemistry using a mouse monoclonal antibody to human cyclin A. Response evaluation was performed according to WHO recommendations. The median cyclin A positivity of tumour cells was 14.5% (range 1.2–45.0). Cyclin A correlated statistically significantly to all other tested proliferation markers (mitotic count, histological grade and Ki-67). A high cyclin A correlated significantly to a shorter time to first relapse, risk ratio (RR) 1.94 (95% CI 1.24–3.03) and survival from diagnosis, RR 2.49 (95% CI 1.45–4.29), cutoff point for high/low proliferation group 10.5%. Cyclin A did not correlate to chemotherapy response or survival after anthracycline, docetaxel or MF therapy. Of all tumour biological factors tested (mitotic count, histological grade and Ki-67), cyclin A seemed to have the strongest prognostic value. Cyclin A is a good marker for tumour proliferation and prognosis in breast cancer. In the present study, cyclin A did not predict chemotherapy response.