HEAT-SHOCK PROTEIN-27 OVEREXPRESSION IN BREAST-CANCER LYMPH-NODE METASTASIS

Background: Heat shock protein 27 (hsp-27) is overexpressed in similar to 67% pure ductal carcinoma in situ (DCIS), in similar to 50% DCIS a ssociated with invasive ductal carcinoma (IDC), and in similar to 25% IDC alone. If this decrease in hsp-27 expression has a role in the pro gression of malignancy in IDC, we postulate a further reduction in exp ression in nodal metastasis. Methods: To test this hypothesis, we eval uated the distribution of hsp-27 in primary LDC and in synchronous reg ional lymph node metastasis within the same patient by immunohistochem istry. Results: Nine of 30 primary IDCs (30%) and 22 of 30 lymph node metastases (73%) overexpressed hsp-27. Contrary to our hypothesis, of 21 IDCs with no or low hsp-27 expression, 13 (62%) had overexpression of this protein within nodal metastasis. Conclusions: hsp-27 appears t o confer cytoprotection for metastatic cells, which may help explain w hy hsp-27 overexpression is associated with reduced disease-free survi val in breast carcinomas.