A 27 kDa heat shock protein that has anomalous prognostic powers in early and advanced breast cancer

This paper describes a prospective immunohistochemical analysis of 27 kDa heat shock protein (HSP27) in 361 patients with primary breast cancer in relation to disease-free survival (DFS) and survival from first relapse (SR). Oestradiol (ER) and progesterone (PR) receptors were also quantitated and related to the HSP27 data. While ER positively predicted a good outcome for both DFS and SR, HSP27 positivity predicted a prolonged SR but short DFS. The association between HSP27 and DFS only attained statistical significance in node-negative patients. Subgroup analysis reinforced the complementary relationship of HSP27 and ER for SR and opposing influences for DFS. In both node-negative and node-positive women, ER+ HSP27- patients had a longer DFS than ER- HSP27+ counterparts. There was no relationship between HSP27 and overall survival. HSP27 staining was highly correlated with ER but not PR, patient age, tumour size or menstrual status. There was a marginal correlation (P = 0.04) with histological grade with well-differentiated tumours having the highest HSP27. Cox multivariate regression analysis of the contribution of HSP27 in the presence of data on ER, PR, stage, nodal status and histological grade indicated that HSP27 was not of independent prognostic importance for DFS or overall survival and was only of borderline significance for OS (P < 0.07). However, in the absence of ER and PR data, HSP27 staining is an effective way of getting the same prognostic information. HSP27 staining appears to correlate with different biological features in early and advanced breast, high HSP27 being linked with short DFS in node-negative patients but with prolonged survival from first recurrence.