Immunohistochemical study of disrupted breast myoepithelial cell : implications for tumor metastasis

الملخص EN

Previous studies detected focal disruptions in my epithelial cell layers of several ducts with carcinoma in situ of breast.

The cell cluster overlying each of the my epithelial disruptions showed a marked reduction in or a total loss of immunoreactivity for the estrogen receptor (ER).

This is in contrast to the adjacent cells within the same duct, which were strongly immunoreactive for the ER.

Paraffin sections from 55 patients with ER-positive intraductal breast tumors were double immunostained in the current study.

Cross-sections of ducts lined by ≥ 40 epithelial cells were examined for my epithelial cell layer disruptions and for ER expression.

Of the 55 cases with 1424 duct cross-sections examined, 24 showed disrupted my epithelial cell layers with 101 focal disruptions.

Of the 24 cases, 20 (84%) contained only ER-negative cell clusters, two (8%) contained both ER-negative and ER-positive cell clusters, and two (8 %) contained only ER positive cell clusters overlying disrupted my epithelial cell layers.

Of the 101 disruptions, 88 (87%) were overlain by ER-negative cell clusters and 13(12.8 %) were overlain by ER-positive cell clusters (P < 0.01).

It is concluded that cells overlying focally disrupted my epithelial layers and their adjacent counterparts within the same duct displayed different immunohistochemical and molecular features.

These features potentially represent an early sign of the formation of a biologically more aggressive cell clone and the my epithelial cell layer breakdown possibly associated with tumor progression or invasion.