Interpretation guidelines of DNA histograms from tissue sections of breast cancer.

BACKGROUND

Evaluation of nuclear DNA staining intensity from histological breast cancer sections has not always been accepted, because of the difficulties in interpreting the histograms. One reason for this is the lack of evidence based interpretation guidelines.

MATERIALS AND METHODS

The DNA staining intensity of 140 breast cancer samples was measured with flow cytometry (FCM) and image cytometry (ICM). The methods were compared by using grading efficiency (GE).

RESULT

First, the ICM histograms were evaluated with a computer assisted image cytometry system using different cut off points for aneuploidy. The GE results varied from 67.9-76.4%. Subjective interpretation and evaluation according two previously published interpretation methods did not improve the GE. Secondly, we excluded histograms which showed clearly different cell clones in FCM and ICM. The GE of remaining histograms was 77.9%. Comparison of these histograms allowed formulation of interpretation guidelines which improved the GE to 85.3%.

CONCLUSIONS

This study suggests that efficient interpretation guidelines of section-based DNA histograms can be created.