Research article
Breast cancer stage at diagnosis and area-based socioeconomic status: a multicenter 10-year retrospective clinical epidemiological study in China
1 Department of Epidemiology, West China School of Public Health, Sichuan University, 16 Ren Min Nan Lu, Chengdu, Sichuan 610041, China
2 Department of Cancer Epidemiology, Cancer Institute & Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, 17 South Panjiayuan Lane, Beijing 100021, China
3 Department of Pathology, Cancer Institute & Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, 17 South Panjiayuan Lane, Beijing 100021, China
4 Center of Breast Disease, Cancer Institute & Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, 17 South Panjiayuan Lane, Beijing 100021, China
5 Department of Breast Surgery, Liaoning Cancer Hospital, 44 Xiaoyanhe Road, Dadong District, Shenyang 110042, China
6 Department of Breast Surgery, Zhejiang Cancer Hospital, 38 Banshanqiao Guanji Road, Hangzhou 310022, China
7 Department of Breast Oncology, Sun Yat-Sen University Cancer Center, 651 Dongfeng East, Gungzhou 510060, China
8 Department of Breast-thyroid Surgery, Xiangya Sencod Hospital, Central South University, 139 Renminzhonglu, Changsha 410011, China
9 Department of Breast Surgery, the Second People's Hospital of Sichuan Province, Chengdu 610041, China
10 Department of Oncosurgery, the First Affiliated Hospital of Medical College, Xi'an Jiao Tong University, 277 Yanta West Road, Xi'an 710061, China
BMC Cancer 2012, 12:122 doi:10.1186/1471-2407-12-122
Published: 29 March 2012Abstract
Background
Although socioeconomic status (SES) has been focused on as a key determinant of cancer stage at diagosis in western countries, there has been no systemic study on the relationship of SES and breast cancer stage at diagnosis in China.
Methods
The medical charts of 4,211 eligible breast cancer patients from 7 areas across China who were diagnosed between 1999 and 2008 were reviewed. Four area-based socioeconomic indicators were used to calculate area-based SES by cluster analysis. The associations between area-based SES and stage at diagnosis were analyzed by trend chi-square tests. Binary logistic regression was performed to estimate odds ratios for individual demographic characteristics' effects on cancer stages, stratified by area-based SES.
Results
The individual demographic and pathologic characteristics of breast cancer cases were significantly different among the seven areas studied. More breast cancer cases in low SES areas (25.5%) were diagnosed later (stages III & IV) than those in high (20.4%) or highest (14.8%) SES areas (χ2 for trend = 80.79, P < 0.001). When area-based SES is controlled for, in high SES areas, cases with less education were more likely to be diagnosed at later stages compared with more educated cases. In low SES areas, working women appeared to be diagnosed at earlier breast cancer stages than were homemakers (OR: 0.18-0.26).
Conclusions
In China, women in low SES areas are more likely to be diagnosed at later breast cancer stages than those in high SES areas.



