Predictive of 21-gene recurrence score assay in non-estrogen receptor-positive and lymph node-negative breast cancer.

The 21-gene recurrence score (RS) assay predicts relapse of estrogen receptor-positive and lymph node-negative breast cancer more accurately than traditional markers; however, whether this assay can be regarded as a molecular marker of other types of breast cancer is unclear. We aimed to identify the effect of 21-gene recurrence score assay in non-estrogen receptor-positive and lymph node-negative breast cancer.We analyzed 21-gene expression by quantitative real-time PCR (qRT-PCR) in 100 cases of breast cancer tissues and followed up for 5 years to investigate the prognostic significance in non-estrogen receptor-positive and lymph node-negative breast cancer. Also, the correlation between RS and the clinicopathological features were analyzed. Adjuvant online (AOL) database was used for the analyses in the present study.The cases were classified as RS low (n=52), moderate (n=22) and high (n=26) risk. The RS based on the21-gene assay was not correlated with age, tumor size, histological grade, and lymph node and estrogen receptor/progesterone receptor (ER/PR) status; however, there was significant correlation with Her-2 status. The 5-year recurrence rates were 1.92%, 4.55% and 15.38% in the low, moderate and high-risk groups, respectively. In addition, there was significant difference between the low-high groups (p<0.05). Furthermore, the consistency of the prognosis predicted by the AOL system was 56% and 59% in the RS moderate-high risk and low risk groups, respectively.The 21-gene RS assay was a prognostic indicator for patients with non-ER-positive and lymph node-negative breast cancer. In addition, our results coincided with those obtained using the AOL system.