Obesity can reduce the effectiveness of some breast cancer treatments in post-menopausal women, according to new research.
University of Auckland researchers carried out a systematic review of eight studies on the treatment.
It looked at aromatase inhibitors, which stop post-menopausal women producing oestrogen, as oestrogen stimulates the growth of certain breast cancer cells.
The research found the inhibitors may be less effective in obese women because fatty tissue carries greater quantities of the enzyme.
However, more information is needed before clinical recommendations can be made, they say.