ESR1 and breast cancer: Median tumor size (2.05 cm vs. 2.1 cm; p = 0.46), tumor grade, median number of metastatic lymph nodes (1 vs. 0.5; p = 0.79), ER status (p = 0.97), PR status (p = 0.28), HER-2 status (p = 0.46) or molecular subtypes of BC (p = 0.60) did not show any statistical difference between the two study groups (Table 1).