Clinical significance of pS2 protein expression in breast cancer

Objective To explore the relationship between the expression of pS2 protein and the clinicopathological parameters in breast cancer and to evaluate the value of pS2 as a prognostic factor for breast carcinoma and a predictive factor for response to endocrine therapy. Methods Expression levels of pS2 protein, estrogen receptor (ER) and progestogen receptor (PR) in tissues from 75 cases of breast cancer were detected by immunohistochemical assay. The relationship of pS2 protein expression with patient age, menopausal status, tumor size, metastasis to the axillary lymph nodes, pathological types, ER and PR was analyzed. Results pS2 protein, expressed in 33.3% of breast carcinomas, was correlated with patient age and pathological types, but was not correlated with tumor size. The positive rate of pS2 protein before menopause was higher than that after menopause, but no significant difference was found. Similarly, higher positive rate of pS2 protein was found in patients with metastasis to axillary lymph nodes than those without, but no significant difference was found. pS2 expression was correlated with ER and PR, but they were not perfectly consistent. Conclusion In breast cancer, pS2 protein expression, associated with some clinical factors and pathological features, is a good prognostic factor. pS2 expression may be a reasonable index for endocrinotherapy of breast carcinoma, but the detection of pS2 protein can not be employed in place of the detection of ER and PR.