Objective   This study aimed to compare the differences in molecular subtypes between Uygur and Han patients with breast cancer. This study was also conducted to provide clinical recommendations.

  Methods   The new typing standard of St. Gallen International Expert Consensus on the Primary Therapy of Early Breast Cancer 2011 was used to classify the molecular subtypes of 369 breast cancer cases from the First People's Hospital of Kashgar Prefecture, Xinjiang Uygur Autonomous Region, China. Four immunohistochemical markers (ER, PR, HER-2, and Ki-67) were used to divide the patients into four intrinsic subtypes: Luminal A; Luminal B (divided into HER-2 negative subtype and HER-2 positive subtype); HER-2 enriched; and triple negative breast cancer (TNBC) subtype. Statistical analysis was then conducted to evaluate the differences in molecular subtype characteristics of Uygur and Han patients with breast cancer.

  Results   The proportion of Luminal A, Luminal B with HER-2 negative subtype, Luminal B with HER-2 positive subtype, HER-2 enriched, and TNBC subtype were 12.67% (36/284), 34.51% (98/284), 20.07% (57/284), 14.79% (42/284), and 17.96% (51/284) for 284 Uygur patients with breast cancer; the corresponding proportions were 16.47% (14/85), 37.65% (32/85), 10.59% (9/85), 10.59% (9/85), and 24.71% (21/85) for 85 Han patients with breast cancer, respectively. The HER-2 positive rates of Uygur and Han patients with breast cancer were 34.86% (99/284) and 21.18% (18/85), respectively. The proportions of Luminal B with HER-2 positive subtype and HER-2 positive rate were significantly higher in Uygur patients than in Han patients (P=0.045 and P=0.030, respectively).

  Conclusions   A larger proportion of Luminal B with HER-2 positive subtype and a higher HER-2 positive rate were observed in Uygur patients with breast cancer than in Han patients with the same disease. HER-2-targeted therapy could be more effective for Uygur patients with breast cancer than for Han patients.