DNA flow cytometry of human breast carcinomas and its relationship to transferrin and epidermal growth factor receptors

The expression of transferrin and epidermal growth factor receptors in breast carcinomas, as detected by immunohistochemistry, has been compared with DNA ploidy and S-phase content of the same tumours as determined by DNA flow cytometry of fixed, paraffin embedded tissue, and with tumour differentiation. Good correlations have been found between DNA ploidy, S-phase content and differentiation. The expression of transferrin receptor appears to relate to DNA ploidy, but only to a limited extent to S-phase content, indicating that in breast carcinomas immunoreactive transferrin receptor may not be directly related to proliferation. The presence of epidermal growth factor receptor shows a close correlation with high S-phase content, but only a lesser association with DNA ploidy, and no correlation with tumour differentiation. DNA flow cytometry provides a more reliable method of assessing the relationship of such growth factor receptors in breast carcinomas to cell proliferation, than that obtained from more subjective tumour grading criteria.