This study is experimental and will prospectively assess the proportion of patients in the two (2) MammaPrint Risk categories in patients of Chinese descent.

The incidence of breast cancer in Chinese women is lower than that of a Western population. Breast cancer is the most common cancer in Chinese women and the incidence is rising. Moreover there are more premenopausal women with breast cancer where the breast cancer incidence peaks in the forties and the postmenopausal rise in incidence is less commonly seen. As the genetic predisposition to breast cancer is increasingly understood, it has been suggested that the differences in breast cancer incidence in different ethnic populations is potentially due to interactions between lifestyle and genetic characteristics. To date, the use of Agendia's gene expression assays in Chinese women has not been studied. In this study, the feasibility of the gene-expression prognostic assays for risk assessment in this specific group will be assessed. Moreover, the specific molecular characteristics and potential biomarkers will be studied, focusing especially on the large group of premenopausal breast cancer patients.

Inclusion Criteria:

• Females aged 18 year to 70 year,
• diagnosis of Stage I or Stage II (excluding those involving more than 3 lymph nodes) Breast Cancer
• Chinese descent

Exclusion Criteria:

• Stage II Breast Cancer with more than 3 positive lymph nodes

Women of Chinese Descent with Stage I or Stage II Breast Cancer