Much of what we know about breast cancer comes from studies involving Caucasian women in Western countries. But research in Singapore has found differences in certain breast cancer characteristics among Chinese, Malay and Indian women.
Dr Lim Siew Kuan, senior consultant and breast surgeon at Solis Breast Care and Surgery Centre, said that breast cancer is classified in different ways. One classification describes where the cancer originates within the breast, while another describes its biological behaviour and how it is likely to respond to treatment.
For example, invasive ductal carcinoma (IDC) begins in the milk ducts. “It accounts for around 70 to 80 per cent of invasive breast cancers worldwide,” said Dr Lim. “This is true across all ethnic groups, including Asian women.”
HER2-positive breast cancer, on the other hand, refers to a molecular subtype, she added. HER2 stands for human epidermal growth factor receptor 2 – the cancer cells have increased HER2 activity, which can drive their growth.
Adjunct Associate Professor Samuel Ow, senior consultant at the Department of Haematology-Oncology at National University Cancer Institute, Singapore, said Asian women have a slightly higher proportion of HER2-positive breast cancer – around 19 per cent, compared with 14 per cent in Caucasian women.
“HER2 used to have a poor outlook,” he told CNA Women. “The good news is that we now have targeted therapy which specifically blocks HER2, and HER2-positive breast cancer can be treated very effectively.”
BREAST CANCER AND ETHNICITY
Dr Lim said research has shown that breast cancer patterns can vary between populations. Studies from Singapore have identified differences in the distribution of breast cancer subtypes among Chinese, Malay and Indian women.