Overexpression of heat shock protein 27 (hsp-27) is associated with reduced disease-free survival in early stage breast cancer. Histopathologic evidence of confluent necrosis within primary infiltrating ductal carcinoma (IDC) is similarly an indication of poor prognosis. We postulated that IDC evidencing confluent tumor necrosis (TN) might overexpress this protein, which would help explain why hsp-27 is associated with higher-risk cancers. To test this hypothesis, presence of TN (as opposed to individual cell apoptosis) and of hsp-27 expression by immunohistochemistry were evaluated independently in 48 specimens of IDC. Nineteen (40%) overexpressed hsp-27 and 10 (21%) displayed necrosis. IDCs with areas of TN are less likely to overexpress hsp-27, suggesting a lack of association between these histoprognostic variables. This negative correlation, however, supports hsp-27 as an independent predictor of high-risk disease.