Characteristic of ER+/PR- and Ki67 value with breast cancer

Breast cancer subtype was defined by ER, PR, HER2 and Ki67 status since the definition of intrinsic subtypes for breast cancer was renovated in 2013 St. Gallen Consensus Conference. The level of ER, PR, HER2 and Ki67 are the main predictive and prognostic biomarkers in various breast carcinoma subtypes. We retrospectively analyzed clinic pathological parameters and immunohistochemical features of 398 breast cancer patients receiving surgery in our hospital from January 2012 to December 2015. Progress free survival was followed up, and logistic regression was applied to estimate the factors associated with high risk of progression. Among all women with breast cancer, recurrence was higher with low ER levels (HR: 5.59, 95% CI: 2.42-12.95, P< 0.001), low PR levels (HR: 0.19, 95% CI: 0.04-0.90, P = 0.036), and high Ki-67 proliferation index (HR: 5.84, 95% CI: 1.91-17.85, P = 0.002). We found that the tumors were larger in patients with ER+/PR- than those with ER+/PR+ (P< 0.001), and pathological staging II/III were more frequently found in ER+/PR- tumors (P< 0.001). It was also shown that the high Ki67 level (>= 20%) (P< 0.001) and HER2-positive status (P = 0.019) were more frequently found in patients with ER+/ PR-than ER+/PR+. Patients with higher Ki67 expression (>= 20%) were younger than those with lower Ki67 expression (P< 0.001), and Ki67 was higher in larger tumor size (P = 0.012). Tumor grade III was more easy to find higher Ki67 (P< 0.001). Collectively, PR- breast tumors were more likely to have an aggressive phenotype than PR+ breast tumors by comparing the ER+/PR+ tumors with ER+/PR- tumors. We also found that higher Ki67 expression was associated with age, tumor size and tumor grade.