Stereologic correlates of steroid receptor concentration in invasive ductal breast cancer

The hypothesis was tested that morphometric parameters of tumor cell nuclei correlate with the steroid receptor concentration in mammary carcinoma. In 50 consecutive mastectomy specimens with a diagnosis of invasive ductal cancer in which estrogen receptor (ER) and progesterone receptor (PR) concentrations had been assayed quantitatively, morphometric measurements were performed on four visual fields of two sections per case. The fields were sampled from the most cellular regions of the tumor. The number of tumor cell nuclear profiles per tissue area, the nuclear profile area and the long and short nuclear profile axes and their ratios were measured with a semiautomatic image analysis system. Estimates of the number of tumor cell nuclei per tissue volume (Nv) and of the mean tumor cell nuclear volume (V) were obtained by standard stereologic techniques. Association between the morphometric and biochemical parameters was tested by Spearman's rank correlation coefficient. Nv correlated positively with the steroid receptor concentration whereas V correlated negatively with both ER and PR concentrations. A correlation of the receptor concentrations to the standard deviation of the nuclear area or the mean ratio of the nuclear axes could not be demonstrated. These results suggest that receptor-rich tumors have a large number of small tumor cell nuclei whereas receptor-poor tumors have a small number of large tumor cell nuclei per tissue volume in the actively proliferating, highly cellular regions. These differences are not accompanied by significant changes in nuclear size variability or nuclear shape.