Breast cancer screening in Taiwan and China

In contrast to incidence rates prevailing in women in Western countries, Chinese women in Taiwan and China are considered to have the lowest incidence of breast cancer in the world. However, in the past 20 years, breast cancer incidence in Chinese women has seen a dramatic increase of 50-100%, which strongly supports the need for breast cancer prevention and screening programs. It is also important to indicate that breast cancer in Chinese women is characterized by younger age at tumor onset. More than 50% of the total breast cancer diagnosed annually is found in premenopausal patients, creating the need to initiate breast cancer screening programs in this population. Initially, the breast cancer screening program depended on breast self-examination. Since Chinese women have relatively small breasts, it was assumed that breast cancer was easier to detect by self-examination. However, this strategy has failed. The dilemma of breast cancer screening can be summarized by the fact that Chinese have a rapidly increasing incidence of premenopausal breast cancer, while the overall incidence is still low. Therefore, since premenopausal women have denser breasts than postmenopausal women, and Chinese women have smaller breasts and a higher percentage of dense breasts, increased mammography screening frequency may be not the sole solution to increase detection in this age group. In our experience in Taiwan, the addition of breast ultrasound may be helpful. Nearly all the nonpalpable cancers detected by mammography in our women are due to microcalcifications, and ultrasound is more sensitive in detecting nonpalpable cancers; Therefore, we suggest that a screening program, based on ultrasound to detect nonpalpable cancers not associated with microcalcifications, along with mammography within a long period, may provide more effective protection for Taiwanese and Chinese women against breast cancer.