The clinicopathologic characteristics of entire cohort and association between Ki-67 and clinicopathologic characteristics.

aTumor stages: T1, tumor nodule is less than 2 cm; T2, tumor size is between 2 cm and 5 cm; T3, tumor size is larger than 5 cm; T4, tumor has grown through skin or chest wall. *Significant difference between percentage of samples with Ki-67 expression ≤25% positive versus those with >25% positivity by using chi-square/Fisher's exact test. ER, estrogen receptor; PR, progesterone receptor.