The relationship of nuclear staining density and mode of stromal invasion with axillary metastases and hormone receptor status in human breast cancer.

Biopsies from 52 cases of infiltrating duct carcinoma of breast were assessed for proportions of tumor infiltrating stroma as "thin" strands and as confluent cell sheets. The proportions of cell nuclei arbitrarily designated "dark" were determined for each whole tumor and for their above-mentioned invasive compartments and were compared with the tumor's nuclear grade, mitotic index, gross size, axillary metastatic status, and hormone receptivity. Well-differentiated tumors tended to have more cells with "dark" nuclei and more of the tumor mass invading the stroma as "thin" strands than poorly differentiated ones. Tumors that had axillary metastases also tended to have high mitotic indices, low proportions of cells with "dark" nuclei (and conversely high proportions of cells with vesicular nuclei) in confluent sheets. Tumors that had positive results for one or both hormone receptors had a greater component of trabecular stromal invasion than tumors with negative results for both hormone receptors that grew as confluent cell sheets. It is suggested that tumor cell nuclear staining "density" might be a clinically useful prognostic index despite the finding that semiquantitative assessments of nuclear density can be modified by the mode of stromal invasion.