PGR and neoplasm: Our pooled results demonstrated no relationship between BTD and grade III subgroup (HR: 0.77, 95%CI: 0.13-4.58, I2 = 85.9%, p=0.008, n=2), tumor>20mm subgroup (HR: 0.87, 95%CI: 0.18-4.13, I2 = 89.7%, p=0.002, n=2), estrogen receptor-negative subgroup (HR: 1.03, 95%CI: 0.80-1.32, I2 = 77.2%, p=0.001, n=4) and progesterone receptor-negative subgroup (HR: 1.19, 95%CI: 0.83-1.71, I2 = 82.8%, p=0.001, n=3).