Researchers have found another health benefit of breastfeeding, it has been linked to a reduced risk of cancer of the uterus.

An international study, led by Australian researchers at the QIMR Berghofer Medical Research Institute, found women who breastfed at least one child for nine months had an 11 per cent lower risk of developing the common cancer compared to those who had never breastfed.

The findings have been published in the journal Obstetrics and Gynecology.

Cancer of the uterus - also known as endometrial cancer - is the fifth most common cancer in Australian women.

Rates have been increasing over recent decades and Cancer Australia estimates that nearly 2,900 new cases will be diagnosed in 2017.

The head of QIMR Berghofer's Cancer Causes and Care Group, Dr Susan Jordan, and her colleagues examined data from more than 26,000 women with at least one child, including nearly 9,000 women with uterine cancer.

"When women breastfed for between three and six months, their risk dropped by about seven per cent per child compared to women with children who didn't breastfeed. And when women breastfed for between six and nine months, their risk dropped by 11 per cent for each child they nursed," Dr Jordan said.

While the reduction plateaued at nine months, for every additional child breastfed, the risk was further reduced.

"In other words, a woman who breastfed two children for nine months each had around a 22 per cent lower risk of uterine cancer than a woman who had never breastfed her children," Dr Jordan said.

Numerous studies have identified a link between breastfeeding and decreased risk of breast cancer, however the relationship between nursing and uterine cancer had been "inconclusive".

"On the basis of this study, we can now confirm that there is a link between breastfeeding and decreased risk of uterine cancer," she said.

It's plausible, says Dr Jordan, that breastfeeding reduces the risk by suppressing ovulation and reducing estrogen levels and in turn reduces the cell division in the lining of the uterus.

Breastfeeding won't guarantee that a woman won't develop cancer of the uterus but supporting women to breastfeed could help reduce the incidence of this often hard-to-treat disease, she said.

"It's already well known that breast feeding has lots of great benefits for mums and their babies. This is just one more benefit to add to the list," she said.