Breast cancer is one of the most common cancers affecting women and early diagnosis is essential. The most common type of non-invasive breast cancer is ductal carcinoma in situ (DCIS), where there are abnormal cells but they have not become malignant. Although China and the US both see similar numbers of breast cancer cases, the proportion of DCIS cases is drastically different.
In the eight major pharmaceutical markets (8MM) of the US, France, Germany, Italy, Spain, the UK, Japan, and urban China, GlobalData epidemiologists estimated that the US had the highest proportion of non-invasive DCIS breast cancer, relative to invasive breast cancer, with 17.18% in 2015 (Figure 1).
In contrast, urban China is estimated to have the lowest proportion of non-invasive DCIS to invasive breast cancer, with 3.01% (Figure 1). Although the US and urban China have a similar number of diagnosed incident cases of invasive breast cancer (241,808 and 211,060, respectively), the amount of DCIS relative to invasive is quite low for urban China (Figure 2).
GlobalData epidemiologists attribute the low proportion of DCIS in urban China to the lack of population-based screening programmes and not enough funding. As a result, the early stage, non-invasive breast cancer remains undetected. This contrasts sharply with the US, where effective screening programmes have been going on for the past few decades. In the future, increased disease awareness, effective use of screening programmes, and increased resources for follow-up treatment will play a role in China’s ability to detect early stage, non-invasive breast cancer.
GlobalData (2016). EpiCast Report: Breast Cancer (HER2+, HER2-) – Epidemiology Forecast to 2025, December 2016, GDHCER133-16.