Urban rural disparity in female breast cancer incidence rate in China and the increasing trend in parallel with socioeconomic development and urbanization in a rural setting

BACKGROUND Worldwide breast cancer incidence correlates with socioeconomic status and increases in parallel with westernization, however urban-rural disparity and trends have not been adequately investigated in China. METHODS The age standardized rate (ASR) of female breast cancer by population-based cancer registration was compared between urban Shijiazhuang city and rural Shexian County in relation to socioeconomic status. The increasing trend of breast cancer in Shexian County from 2000-2015 was examined using Joinpoint analysis and the correlation with gross domestic product (GDP) per capita was analyzed. RESULTS In 2012, the ASR of female breast cancer in Shijiazhuang was more than three times higher than in Shexian County (45.5/1 00 000 vs.13.8/1 00 000; P < 0.01) when the GDP per capita was 2.6 times higher (US$6964.80 vs. US$2700). In parallel with rapid socioeconomic development and urbanization, the biennial ASR of female breast cancer in Shexian county has increased significantly from 2.8/1 00 000 in 2000-2001 to 17.3/1 00 000 in 2014-2015, with an average biennial percent change of +10.2% (P < 0.01). The Pearson correlation between ASR and GDP was significantly positive (r = 0.94, P < 0.01). CONCLUSION The incidence of breast cancer in women in China is increasing along with lifestyle westernization and changing reproductive patterns associated with socioeconomic development and urbanization. Urgent prevention measures, including the development of a healthy diet, giving birth at a younger age, an increase in breastfeeding, limiting menopause estrogen therapy, and control of alcohol consumption, are required.