Cancer News: Induced abortion boosts breast cancer risk - new study
By David Liu, PHD
Wednesday April 25, 2012 (foodconsumer.org) -- Doctors particularly those who practice abortion may tell you abortions do not increase risk for breast cancer. The fact is that induced abortion can increase the risk. A recent case-control study released recently in Asian Pacific Journal of Cancer Prevention confirmed that induced abortions boost risk of breast cancer.
The study led by A.R. Jiang and colleagues from Jiangsu Province Institute of Cancer Research in Nanjing, China showed premenopausal women who had induced abortion three or more than three times were 141 percent more likely to develop breast cancer than those who had never had induced abortion. The increase in the risk of breast cancer after adjustment for other factors was 55 percent among premenopausal women.
The researchers also found that of postmenopausal women, those who had one induced abortion previously were also at 100% increased risk for breast cancer. The increase in the risk was 82 percent after adjustment for other factors among postmenopausal women.
Induced abortion was positively associated with risk of breast cancer, meaning more induced abortions lead to high risk of breast cancer, according to the researchers.
However, spontaneous abortion was not found associated with risk of breast cancer except that among postmenopausal women, those who had history of spontaneous abortion were also at increased risk for breast cancer.
The findings were derived from an analysis of 669 cases of breast cancer and 682 population-based controls in Jiangsu Province of China.
This is not the first study that shows that induced abortion increases risk of breast cancer. It's known that women's breasts are immature and susceptible to mutations which can lead to breast cancer development, prior to a full term pregnancy.
Here is how. When a pregnancy starts, the breast tissue is growing to a stage at which if the pregnancy is terminated by doctors, the breast remains in such a stage where the breast tissue is vulnerable to mutagenesis and carcinogenesis. However, when the pregnancy is completed, the breast tissue becomes mature and resistant to mutagenesis and carcinogenesis. That is why a full term pregnancy at a young age can help prevent the breast from developing cancer.
From the same study population, Y.T. Liu and colleagues of the same organization also found that early ages at menarches (<13 years), late ages at menopause (>50 years) and older ages at first pregnancy (>30 years) were associated with increased risk of breast cancer.
However, this study published in 2011 in the same journal also showed that breastfeeding was associated with a 55 percent reduced risk for breast cancer and longer breastfeeding was linked to lower risk.