HRT: Conflicting reports on risk of breast cancer recurrence

"New follow-up study of HRT in breast cancer survivors published 25th March 2008", Journal of the National Cancer Institute

A clinical trial of HRT in women with previous breast cancer – the HABITS trial – that was prematurely terminated because of an increased risk of recurrence has shown that this risk persists during a follow-up of 2 years1. Confusingly, a study of very similar size and duration,called the Stockholm study, quite clearly showed that there was absolutely no increased risk of breast cancer recurrence2. Thus, the issue of whether or not HRT increases breast cancer risk remains unresolved. The authors of the study reasonably conclude that clinicians and their patients should weigh the HRT benefits of menopausal symptom relief against any increased risk of breast cancer recurrence. It is therefore most unfortunate that an accompanying editorial3 seeks to sensationalise the results as showing clear-cut harm from HRT. What does seem clear is that there is little or no increased risk from oestrogen-alone HRT4, and that there does not appear to be any increased risk of dying from breast cancer in HRT users5. There may be some increased risk of developing breast cancer in users of combined oestrogen-progestogen HRT, but this risk needs to be put into proportion, being smaller than the increased risk for breast cancer seen with being overweight or drinking alcohol for example. Women on HRT for symptom relief or prevention of osteoporosis can be reassured that the benefits far outweigh any risks. Clinicians usually recommend that women who have previously had breast cancer avoid HRT, but for individuals whose lives are marred by menopausal symptoms the use of HRT may sometimes be justified.

Dr John C Stevenson

Chairman, Women’s Health Concern
Consultant Physician and Reader, National Heart & Lung Institute, Imperial College London


1 Holmberg L, Iversen O-E, Rudenstam CM, et al. Increased risk of recurrence after hormone replacement therapy in breast cancer survivors. J Natl Cancer Inst 2008; 100: 475-82

2  von Schoultz E, Rutqvist LE. Stockholm Breast Cancer Study Group. Menopausal hormone therapy after breast cancer: the Stockholm Randomized Trial. J Natl Cancer Inst 2005; 97: 533-35

3 Pritchard KI. Should observational studies be a thing of the past? J Natl Cancer Inst 2008; 100: 451-52

4 Stefanick ML, Anderson GL, Margolis KL, et al. Effects of conjugated equine estrogens on breast cancer and mammography screening in postmenopausal women with hysterectomy. JAMA 2006; 295: 1647-57

5 Chlebowski RT, Hendrix SL, Langer RD, et al. Influence of estrogen plus progestin on breast cancer and mammography in healthy postmenopausal women. JAMA 2003; 289: 3243-53

2015-02-09T20:28:25+00:0025 March 2008|