In a large population-based study out of Western Australia, researchers have found that IVF is not associated with an overall increased risk of breast cancer. However, the analysis of 20 years’ worth of linked hospital and registry records demonstrates an underlying, age-related connection between IVF treatment and breast cancer. The effect of IVF on breast cancer rates differed depending on the age of the women at the time treatment was commenced. In younger, but not older, patients there was an association between having IVF and an increased risk of breast cancer.