High expression of heat shock protein 10 correlates negatively with estrogen/progesterone receptor status and predicts poor prognosis in invasive ductal breast carcinoma

Heat shock proteins (HSPs) usually are associated with stress response and tolerance. HSP10 is a co-chaperone for HSP60, which is involved in the mitochondrial protein-folding machinery. To the best of our knowledge, the expression of HSP10 in invasive ductal breast carcinoma (IDBC) has never been reported. In the present study, HSP10 expression in 242 cases of IDBC and 46 cases of noncancerous breast tissues was detected by immunohistochemistry staining. High expression was significantly more common in IDBC than in noncancerous breast tissues (P<.001). Also, high expression was significantly more common in poorly differentiated than in well- and moderately differentiated IDBC (P=.023). Furthermore, high expression correlated negatively with estrogen receptor and progesterone receptor expression (P=.031 and P=.042, respectively). The most interesting result of the study was that high expression of HSP10 was significantly associated with shorter overall survival by both univariate and multivariate analyses (P=.013 and P=.036, respectively). In conclusion, we report for the first time that high expression of HSP10 is negatively associated with estrogen receptor/progesterone receptor status and might be a novel independent biomarker for poor prognosis in IDBC.