According to the latest report of The International Agency for Research on Cancer (GLOBOCAN 2012), breast cancer (BC) is by far the world’s most common cancer among women, and the most likely cause that a woman will die from cancer worldwide (1). The disease is reported as the most frequent cancer among women in 140 of 184 countries worldwide including China the world’s most populous country (1,2). Notably, the incidence rates of BC varies dramatically across the globe, being always highest in more developed regions, namely North America, Western Europe (more than 90 new cases/105 women annually), compared with less than 30/105 women annually in regions like Eastern Asia (1). In the current issue of JTD, Zeng et al. (3), have published the first national dataset on the incidence and mortality of female BC in China, for the year 2010, highlighting also some trends in incidence, and mortality, in different geographical regions within China. The authors should be commended for being the first to provide the literature with a wealth of data regarding BC statistics in China, which harbors around one fifth of all women around the world. According to the authors’ estimations, the age standardized incidence rate (ASIR) of BC is 24.2/105 and age standardized mortality rate (ASMR) is 6.36/105. As such, these figures would confirm the known fact, that the mainland Chinese women have one of lowest BC incidence and mortality rates, when compared to the rest of the world. Two important questions should be raised with this kind of findings: how far the authors could accurately quantify BC burden (occurrence and outcome) in China? and if their figures are true, then why the mainland Chinese women are so much protected against BC versus Chinese women in other Asian or western counties? To start with, we need to emphasize that Zeng et al. analysis included only 12.96% of the female population of China. This means that the vast majority of Chinese women are not truly represented in their analysis, especially in the western region (less than 10% of their sample size), where the incidence is ~30% less than that reported in other areas. Obviously, “a cautious interpretation” is warranted with this kind of national epidemiological studies, when so many regions in a given country have low or no accurate registry data. Nonetheless, this is a common situation in many countries with emerging population-based registries (4). For instance, in Egypt; with its much smaller scale in geographical and population size, a network of five regional population-based registries, spreading over the whole country, was developed during the last two decades. For the sake of national cancer statistics, Egypt was divided into three regions namely upper, middle and lower Egypt. One or more defined states (governorates), with a regional population-based registry, were selected to represent each region (4). The data evolved on cancer incidence from each cancer registry were extrapolated in a similar methodology like that adopted by Chinese group. BC is estimated to be the most common female cancer in both China and Egypt, despite a marked difference in incidence rates, being much higher among Egyptian women compared to Chinese (ASIR are 48.8/105 and 24.2/105 respectively) (3,4). In the two countries BC incidence differs considerably among rural and urban populations, with the higher urban incidence being consistent across all women above the age of 45 years (3,5). A similar observation was also found in many developing countries like India, where BC incidence in rural registry of Barshi was 7.2/105 compared to 31.3/105 in adjoining city of Mumbai (6). In fact, the urban population in developing countries, might suffer from a higher exposure to xenoestrogens, which have been linked to evolution of hormone receptor positive BC in industrialized countries (7).