May Million Women study launched to establish whether there is any relation between HRT treatment and risk of breast cancer

August Scientists warn about oestrogen-only HRT increasing risk of uterine cancer

October First alarm about HRT and breast cancer raised after analysis of several studies from across the world. But experts conclude that risks may be outweighed by benefits, including protecting against heart disease

1998

March Pennell report on needs of women over 45 comes down in favour of HRT. The inquiry was supported by the Department of Health and HRT manufacturer Wyeth

2001

March Increased risk of ovarian cancer found among women on oestrogen-only HRT

April Panel of experts warns that trials question any benefit from HRT on heart disease, Alzheimer's disease, depression or incontinence

July 16,600 women on HRT study in the US told to stop taking drug after government scientists say it significantly increases breast cancer, stroke and heart attack risk

October £20m international trial involving 5,000 British women abandoned because it would take too long (13 years). Organisers insist there was no question over HRT's overall safety record

2003

August Million Women study publishes first results, confirming breast cancer risks