Subsequently, women have been advised to take HRT for as short a time as possible. But follow-up data from the WHI suggests that the increased cancer risk remains even after stopping HRT.
The latest data comes from follow-up of 15,730 postmenopausal women, aged 50-79, who had participated in the WHI study.
Half the women had been taking oestrogen plus progesterone HRT, but stopped the treatment in 2002 when the WHI study was abandoned. The rest of the women had taken placebo.
Follow-up from July 2002 until March 2005, revealed that 281 women who had received HRT went on to develop cancer, compared with 218 who had not received HRT.
Overall, the combined risk of suffering heart disease, stroke, hip fracture or cancer increased by 12 per cent in the HRT group, compared with the placebo group.
Researchers from the University of North Carolina hope the findings can help calculate optional use of HRT.
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