These authors contributed equally to this study.
Ki67 and cyclin A as prognostic factors in early breast cancer. What are the optimal cut-off values?
Article first published online: 17 AUG 2007
Volume 51, Issue 4, pages 491–498, October 2007
How to Cite
Ahlin, C., Aaltonen, K., Amini, R.-M., Nevanlinna, H., Fjällskog, M.-L. and Blomqvist, C. (2007), Ki67 and cyclin A as prognostic factors in early breast cancer. What are the optimal cut-off values?. Histopathology, 51: 491–498. doi: 10.1111/j.1365-2559.2007.02798.x
- Issue published online: 17 AUG 2007
- Article first published online: 17 AUG 2007
- Date of submission 26 December 2006 Accepted for publication 14 March 2007
- breast cancer;
- cut-off value;
- cyclin A;
- tissue microarray
Aims: To find the optimal cut-off values for cyclin A and Ki67 in early breast cancer tumours and to evaluate their prognostic values.
Methods and results: Tissue microarray (TMA) slides were constructed from 570 T1–4 N0–1 M0 breast cancer tumours. The TMA slides were stained for cyclin A and Ki67 using immunohistochemistry with commercial antibodies. To investigate the optimal cut-off values for cyclin A, Ki67 average and maximum values the material was split into two parts at cut-offs defined by dividing it into deciles. For each cut-off value the relative risk (RR) for metastasis-free survival (MFS) and overall survival (OS) was calculated comparing patients with high versus low cyclin A or Ki67 expression. When using a cut-off value around the seventh decile, cyclin A and Ki67 score correlated with the highest RR ratio for MFS in the chemotherapy-naïve subgroup. Among patients having received adjuvant chemotherapy, no statistically significant differences in MFS or OS were found.
Conclusions: The optimal cut-off value for cyclin A average is 8% and for cyclin A maximum value 11%; for Ki67 the corresponding values are 15% and 22%. Additional studies are needed to verify these results.