Women who experience hot flushes and other symptoms of menopause may have a significantly reduced risk of the most common forms of breast cancer.
A US-based study of more than 1400 post-menopausal women has found that those who experienced the worst symptoms had a 40 to 60 per cent reduced incidence of invasive ductal and invasive lobular carcinoma.
"In particular we found that women who experienced more intense hot flushes - the kind that woke them up at night - had a particularly low risk of breast cancer," said Dr Christopher Li, from the Seattle-based Fred Hutchinson Cancer Research Centre.
"While menopausal symptoms can certainly have a negative impact on quality of life, our study suggests that there may be a silver lining."
The symptoms occur as a woman's oestrogen and progesterone levels fluctuate and drop, and the same hormones play an important role in the development of most breast cancers.