Childbirth can elevate risk of breast cancer

Chennai: Childbirth can increase the risk of breast cancer, finds a recent study published in the Annals of Internal Medicine.  The study found that breast cancer risk elevated in women who had given birth and were aged 55 or younger. The extensive analysis used data from 15 studies that monitored breast cancer risk factors for over eight lakh women.

Researchers found that childbirth only benefits women above a certain age when it comes to breast cancer risk levels. It is believed that childbirth can protect women against breast cancer, but the recent study suggests that the ‘protective effect’ can be effective only after 20 years.

The study found that younger women who had recently given birth had higher risk of breast cancer. The highest risk of developing breast cancer was about 80 per cent within five years after pregnancy, when compared with women who had not gone through childbirth.

Women with a family history of breast cancer, who were older at the time of first pregnancy and who had more children were found to have higher risk of breast cancer. However, the study revealed that the breast cancer risk was reduced after 20 years and they experienced a sort of protection from the same.

One of the authors of the study Hazel B. Nichols said, “We found that it can take more than 20 years for childbirth to become protective for breast
cancer, and that before that, breast cancer risk was higher in women who had recently had a child”.

However, the overall risk of developing breast cancer was still relatively low for any woman who had given birth, revealed the study.

“Though the risk of developing breast cancer is different between individuals, childbirth reduces the risk of breast cancer. The pregnancy itself is a low-risk period as the production of estrogen reduces and there is no menstruation. The protective effect of childbirth against breast cancer starts from the time of pregnancy. Even during lactation, women are protective against breast cancer, as the estrogen production is not regular. However, it takes some time for these factors to act against the risk of breast cancer,” says oncologist Dr Anitha Ramesh. Breast cancer may accompany pregnancy and it is very aggressive in that case, however, it is not due to pregnancy that the risk to breast cancer increases, added Dr Anitha.