Clinicopathological Features and Survival for Low ER-positive Breast-cancer Patients.

Context: Testing patients for estrogen-receptor (ER) expression has become an important factor in the prognosis and prediction of breast cancer. Many studies have shown that endocrine therapy has no benefit for breast-cancer patients with low ER (ER+) expression, in which the proportion of positively stained cells is 1% to 9%. Objective: The study intended to explore the response to endocrine therapy of ER+ breast-cancer patients and to evaluate the benefits of the clinical use of endocrine therapy for treatment. Design: The research team designed a retrospective analysis and reviewed the data and survival rates of patients with early breast cancer. Setting: The study took place at the Hebei Breast Disease Clinic at the Fourth Hospital of Hebei Medical University in Shijiazhuang, China. Participants: Eligible participants in the study were 862 patients were diagnosed at and admitted to the clinic with early, nonadvanced breast cancer between January and December 2012. Outcome Measures: Based on ER-expression levels, participants were divided into ER negative (ER-), which indicates no positive staining of cells; ER+; and ER positive (ER++)-high expression in which the proportion of positively stained cells is ≥10%. The clinicopathological characteristics and the survival rates of the three groups were compared. Results: The clinicopathological features were similar for the ER- and ER+ groups. Compared to participants in the ER++ group, participants in the ER+ group: (1) were in an earlier stage, (2) had larger tumors, (3) were more likely to be positive for human epidermal growth factor receptor-2 (HER-2), (4) had a higher expression rate of Ki-67, (5) had a lower progesterone-receptor (PR) expression rate, (6) were more likely to receive chemotherapy, and (7) were less likely to receive endocrine therapy. Regardless of whether a participant received endocrine therapy or not, the seven-year overall survival (OS) between the ER- group and the ER+ group showed no significant difference, but both were in a worse condition than the ER++ group (P = .026). Conclusions: The current study found that the clinicopathological features of ER+ breast cancers were different from those of ER++ breast cancers and similar to those of ER-negative breast cancers. The benefits of endocrine therapy for ER+ breast-cancer patients weren't obvious.