Expression of steroid receptor RNA activator protein (SRAP) could potentially be used as a predictive marker for the clinical outcome of patients with breast cancer, according to a new study.

Breast cancer is one of the most frequently diagnosed malignancies and the second cause of cancer-related deaths among women worldwide. Previous studies have suggested that SRAP plays a part in breast cancer progression. SRAP is expressed in multiple cancer cell lines, and an increase in its expression has been shown during the development and progression of breast, ovarian and uterine cancer.

Researchers from Canada analyzed expression of SRAP by tissue-microarray analysis in 372 breast tumor samples obtained from the Manitoba Breast Tumor Bank to investigate whether SRAP levels in patients with breast cancer are associated with clinical parameters, such as steroid receptor status, node status and outcome.

Expression of SRAP was found to be significantly elevated in tumors of patients aged >64 years and in estrogen and progesterone receptor-positive tumors. Additionally, SRAP expression was negatively associated with breast cancer-specific survival in patients aged ≤64 years with estrogen and progesterone receptor-positive tumors. In patients with estrogen receptor-positive cancers, high expression of SRAP significantly correlated with a higher rate of breast cancer mortality and recurrence compared with patients who had estrogen receptor-negative tumors. In patients aged ≤64 years with estrogen receptor-positive and node-negative tumors, high SRAP expression was also indicative of poor prognosis.

SRAP expression might be predictive of outcome in a specific set of patients with otherwise good prognosis when only considering clinical parameters.