Relationship of DNA ploidy to hormone receptor status and proliferation in invasive breast carcinoma

Purpose: In 247 primary invasive breast carcinomas, DNA ploidy was related to hormone receptor status, proliferation, and clinical/histopathologic factors. Methods: DNA ploidy analysis was performed by image analysis using imprints. Estrogen (ER) and progesterone (PR) receptor status was determined immunohistochemically. The proliferative activity of the tumours was assessed by Ki-67 antigen labelling. Total observation time was 3.5 years. Results: DNA ploidy analysis revealed a high fraction of tumours with non-peridiploid patterns (78%). Significant correlations between DNA ploidy and ER/PR receptor status ( P < 0.01) were found with increased frequencies of peridiploid DNA results in receptor positive tumours. A significant relationship became manifest between DNA ploidy and Ki-67 index showing high frequencies of non-peridiploid DNA patterns in tumours with Ki-67 index >20% ( P < 0.01). There was a strong correlation ( P < 0.001) between DNA ploidy and histopathologic grading, while tumour size and lymph node status were not correlated to DNA ploidy. Conclusions: The results of our study on invasive breast carcinoma demonstrate that DNA ploidy measured by image analysis is predominantly associated with markers of cell differentiation. Preliminary outcome data reveal a risk-indicating potential of DNA ploidy primarily in cases with favourable results for other prognostic factors.