The study examined women over the course of 20 years following surgery undertaken in response to primary breast cancer. The results indicated that breastfeeding for longer than six months was associated with a higher survival rate compared with women who did not breastfeed.
The research examined 629 women with primary breast cancer, who had undergone surgery between 1988 and 1992. Of these 341 were traced and consequently studied over the course of 20 years in relation to breastfeeding and reproductive activity.
The conclusion was that a total breastfeeding history of greater than six months and pregnancy are associated with both greater overall and breast-cancer-specific survival.
The study is important because it is the first to examine the link between lifetime breastfeeding history and both breast cancer-specific and overall survival among women treated for breast cancer (that is with women who had lived long enough for other causes of death to contribute substantially to mortality).
Researchers are not exactly sure why this effect occurs. It could be because a woman’s ovaries do not produce eggs so often when they are breastfeeding. Or it may be because breastfeeding changes the cells in the breast and makes them more resistant to the changes that lead to cancer.
The study has been carried out at the University of Linkoping, and County Hospital, Kalmar, Sweden and University of Tromso, Norway.
Commenting on the findings, one of the lead researchers, Professor Arthur I. Eidelman said that the study “confirms that the long-term maternal health benefits of breastfeeding are not only preventative in nature, but that it also has the capacity to reduce the severity of breast cancer.”
The research has been published in the journal Breastfeeding Medicine. The research paper is titled “Breastfeeding Associated with Reduced Mortality in Women with Breast Cancer.”
