Striking life events associated with primary breast cancer susceptibility in women: a meta-analysis study.
OBJECTIVE
The association between striking life events, an important stress and acute anxiety disorder, and the occurrence of primary breast cancer is unclear. The current meta-analysis was designed to assess the relationship between striking life events and primary breast cancer incidence in women.


METHODS
Systematic computerized searching of the PubMed, ScienceDirect, Embase, and BMJ databases with the combinations of controlled descriptors from Mesh, including breast cancer, breast tumor, cancer of breast, mammary carcinoma, life events, life change events, case-control studies, case-base studies, cohort study, and cohort analysis and identified a total of 307 papers published from January 1995 to April 2012. Following evaluation of methodological quality with the Downs & Black criteria, seven case-control or cohort studies were selected and the association between striking life events and primary breast cancer incidence in women was measured using random effect or fixed-effect odds ratios combined with 95% confidence interval.


RESULTS
The seven studies included in the final meta-analysis included 99,807 women. A meta-analysis showed that the pooled OR for striking life events and breast cancer was 1.51 (95% CI 1.15 - 1.97, P = 0.003), indicating that women with striking life events were at 1.5-fold greater risk of developing breast cancer. The pooled OR for severe striking life events and breast cancer was 2.07 (95% CI 1.06 - 4.03), indicating that women with severe striking life events were at 2-fold greater risk of developing breast cancer.


CONCLUSIONS
The current meta-analysis showed significant evidence for a positive association between striking life events and primary breast cancer incidence in women.
Department of Breast Disease, Peking Union Medical College Hospital, Peking Union Medical College, 1 Shuaifuyuan, Wangfujing, Beijing 100730, China. pumclinyan@163.com
Yan
Y
Lin
Changjun
C
Wang
Ying
Y
Zhong
Xin
X
Huang
Li
L
Peng
Guangliang
G
Shan
Ke
K
Wang
Qiang
Q
Sun
D000328:Adult; D001943:Breast Neoplasms / Q000453:epidemiology* / Q000209:etiology / Q000523:psychology; D015331:Cohort Studies; D003625:Data Collection; D004198:Disease Susceptibility; D005260:Female; D006801:Humans; D015994:Incidence; D008016:Life Change Events; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D013315:Stress, Psychological / Q000453:epidemiology*