PGR and neoplasm: Although there was no difference between the two races with regard to BCSS, patients between the ages of 60 and 79 years old (using Caucasian as reference: HR=0.73, 95% CI: 0.59-0.91, P < 0.01), those with a tumor size of 0-2 cm (HR=0.77, 95% CI: 0.63-0.93, P < 0.01), and those who were ER-negative (HR=0.81, 95% CI: 0.69-0.96, P=0.02) and PR-negative (HR=0.83, 95% CI: 0.71-0.96, P=0.01) showed significant differences in BCSS, suggesting that the Chinese patients in these subgroups had better survival than the Caucasians.