Breast Cancer Research and Treatment

, Volume 120, Issue 1, pp 149–160

Urban–rural differences in breast cancer incidence by hormone receptor status across 6 years in Egypt

  • Subhojit Dey
  • Amr S. Soliman
  • Ahmad Hablas
  • Ibrahim A. Seifeldin
  • Kadry Ismail
  • Mohamed Ramadan
  • Hesham El-Hamzawy
  • Mark L. Wilson
  • Mousumi Banerjee
  • Paolo Boffetta
  • Joe Harford
  • Sofia D. Merajver
Epidemiology

DOI: 10.1007/s10549-009-0427-9

Cite this article as:
Dey, S., Soliman, A.S., Hablas, A. et al. Breast Cancer Res Treat (2010) 120: 149. doi:10.1007/s10549-009-0427-9

Abstract

Breast cancer incidence is higher in developed countries with higher rates of estrogen receptor positive (ER+) tumors. ER+ tumors are caused by estrogenic exposures although known exposures explain approximately 50% of breast cancer risk. Unknown risk factors causing high breast cancer incidence exist that are estrogenic and development-related. Xenoestrogens are such risk factors but are difficult to study since developed countries lack unexposed populations. Developing countries have urban–rural populations with differential exposure to xenoestrogens. This study assessed urban–rural breast cancer incidence classified by hormone receptor status using data from Gharbiah population-based cancer registry in Egypt from 2001 to 2006. Urban ER+ incidence rate (per 100,000 women) was 2–4 times (IRR = 3.36, 95% CI = 4.84, 2.34) higher than rural incidence rate. ER−incidence rate was 2–3 times (IRR = 1.86, 95% CI = 2.38, 1.45) higher in urban areas than in rural areas. Our findings indicate that urban women may probably have a higher exposure to xenoestrogens.

Keywords

Breast cancer incidenceHormone receptor statusMammary stem cellsXenoestrogensEgypt

Copyright information

© Springer Science+Business Media, LLC. 2009

Authors and Affiliations

  • Subhojit Dey
    • 1
  • Amr S. Soliman
    • 1
  • Ahmad Hablas
    • 2
  • Ibrahim A. Seifeldin
    • 3
  • Kadry Ismail
    • 2
  • Mohamed Ramadan
    • 3
  • Hesham El-Hamzawy
    • 3
  • Mark L. Wilson
    • 1
  • Mousumi Banerjee
    • 4
  • Paolo Boffetta
    • 5
  • Joe Harford
    • 6
  • Sofia D. Merajver
    • 7
  1. 1.Department of Epidemiology, School of Public HealthUniversity of MichiganAnn ArborUSA
  2. 2.Gharbiah Cancer SocietyTanta, GharbiahEgypt
  3. 3.Tanta Cancer CenterTanta, GharbiahEgypt
  4. 4.Department of Biostatistics, School of Public HealthUniversity of MichiganAnn ArborUSA
  5. 5.International Agency for Research on CancerLyonFrance
  6. 6.Office of International AffairsNational Cancer InstituteBethesdaUSA
  7. 7.University of Michigan Comprehensive Cancer CenterAnn ArborUSA