Urban-rural differences in breast cancer incidence in Egypt (1999-2006).
OBJECTIVE
To describe urban-rural differences in breast cancer incidence in Gharbiah, Egypt and to investigate if these differences could be explained by known risk factors of breast cancer.


METHODS
We used data from the population-based cancer registry of Gharbiah, Egypt to assess breast cancer incidence from 1999 through 2006. The Egyptian census provided data on district-specific population, age, and urban-rural classification. Incidence patterns of breast cancer by district and age-specific urban-rural differences were analyzed.


RESULTS
Overall, incidence rate of breast cancer was three to four times higher in urban areas than in rural areas (60.9/10(5)-year for urban areas versus 17.8/10(5)-year for rural areas; IRR=3.73, 95% CI=3.30, 4.22). Urban areas had consistently higher incidence of breast cancer across all age-groups for all years. Higher incidence of breast cancer was also seen in the more developed districts of Tanta and El-Mehalla.


CONCLUSIONS
Higher incidence of breast cancer in urban and more developed populations might be related to higher exposure to xenoestrogens, as well as other endocrine disruptors and genotoxic substances.
Dey
Subhojit
S
Department of Epidemiology, School of Public Health, University of Michigan, 109 Observatory Street, Ann Arbor, MI 48109, USA. subhojit@umich.edu
Soliman
Amr S
AS
Hablas
Ahmad
A
Seifeldein
Ibrahim A
IA
Ismail
Kadry
K
Ramadan
Mohamed
M
El-Hamzawy
Hesham
H
Wilson
Mark L
ML
Banerjee
Mousumi
M
Boffetta
Paolo
P
Harford
Joe
J
Merajver
Sofia D
SD
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000453:epidemiology*; D002648:Child; D004534:Egypt / Q000453:epidemiology; D005260:Female; D006801:Humans; D015994:Incidence; D008875:Middle Aged; D012042:Registries; D012044:Regression Analysis; D012307:Risk Factors; D012424:Rural Population / Q000706:statistics & numerical data*; D014505:Urban Population / Q000706:statistics & numerical data*; D055815:Young Adult
Int J Environ Health Res. 2004 Apr;14(2):121-34
15203457
J Natl Cancer Inst. 1993 Nov 17;85(22):1819-27
8230262
Environ Sci Technol. 2004 Jan 1;38(1):34-41
14740714
In Vivo. 2000 Jan-Feb;14(1):115-23
10757068
Epidemiology. 2001 Jan;12(1):131-3
11138809
Toxicol Appl Pharmacol. 2008 Aug 15;231(1):112-6
18513777
J Appl Toxicol. 2003 Jan-Feb;23(1):43-51
12518336
Int J Hyg Environ Health. 2007 May;210(3-4):319-33
17400024
J Environ Monit. 2008 Jul;10(7):861-6
18688454
Environ Monit Assess. 2005 Jun;105(1-3):111-20
15952515
Environ Health Perspect. 2005 Apr;113(4):391-5
15811827
Breast J. 2006 Jan-Feb;12 Suppl 1:S70-80
16430400
J Egypt Public Health Assoc. 2002;77(3-4):329-45
17216966
Cancer. 2007 Jun 15;109(12 Suppl):2667-711
17503436
Int J Surg. 2007 Aug;5(4):225-33
17660128
Environ Int. 2004 May;30(3):309-22
14987860
Water Sci Technol. 2002;46(4-5):77-82
12361052
Environ Sci Technol. 2007 Jun 1;41(11):3877-83
17612163
Environ Health Perspect. 2008 Jan;116(1):39-44
18197297
Environ Int. 2007 Jul;33(5):685-93
17367859
Int J Occup Environ Health. 2009 Jan-Mar;15(1):43-78
19267126
Breast Cancer Res. 2004;6(6):229-39
15535852
Environ Res. 2003 Jun;92(2):110-7
12854690
Cent Eur J Public Health. 1996 Dec;4(4):263-5
8997537
J Egypt Public Health Assoc. 1999;74(5-6):547-66
17219863
Environ Health Perspect. 2004 Mar;112(3):331-8
14998749
Ann N Y Acad Sci. 2008 Oct;1140:91-112
18991908
J Natl Cancer Inst. 1995 Dec 20;87(24):1846-53
7494228
Chemosphere. 2008 May;71(11):2082-90
18325564
Am J Epidemiol. 2008 Aug 15;168(4):404-11
18552361
Int J Cancer. 1997 Jan 17;70(2):159-63
9009154
Environ Sci Technol. 2004 Sep 1;38(17):4474-83
15461152
J Steroid Biochem Mol Biol. 2002 Jan;80(1):49-60
11867263
Toxicology. 2004 May 20;198(1-3):91-115
15138034