ObjectiveTo systematically review the correlation between the birth number and the risk of breast cancer of Chinese female.
MethodsWe electronically searched databases including the CNKI, WanFang Data and VIP databases from inception to September 1st 2015, to collect case-control studies about the correlation between the number of births and the risk of breast cancer among Chinese female. Two reviewers independently screened literature, extracted data, and evaluated the risk of bias of included studies. Then meta-analysis was performed by using Stata software.
ResultsA total of 14 case-control studies involving 3 428 patients and 3 906 controls were included. The results of meta-analysis showed that:the females who had term birth had significant lower incidence of breast cancer than those without childbirth history (OR=0.429, 95%CI 0.322 to 0.571). Subgroup analysis based on the number of term birth showed that:Compared with the female without childbirth history, those who had term birth of one time (OR=0.464, 95%CI 0.321 to 0.670), two times (OR=0.394, 95%CI 0.269 to 0.576) and≥3 times (OR=0.340, 95%CI 0.232 to 0.499) had significant lower incidence of breast cancer.
ConclusionTerm birth is a protective factor for breast cancer of Chinese female, and more times of term birth will decrease the risk of breast cancer.
