Research table: Menopausal hormone therapy and breast cancer recurrence

This summary table contains detailed information about research studies. Summary tables are a useful way to look at the science behind many breast cancer guidelines and recommendations. However, to get the most out of the tables, it’s important to understand some key concepts. Learn how to read a research table.

Introduction: Menopausal hormone therapy (MHT) isn’t usually given to women who’ve had breast cancer because findings from large randomized controlled trials have shown MHT use increases the risk of [1-2]:

• Breast cancer recurrence at the original site (local recurrence)
• Metastasis (distant recurrence, the cancer has spread to other parts of the body)
• Cancer in the opposite breast  

MHT is also known as postmenopausal hormone therapy and hormone replacement therapy (HRT).

Women have other options for treating menopausal symptoms.

Learn about MHT and breast cancer risk.

Learn about the strengths and weaknesses of different types of studies.  

Study selection criteria: Randomized controlled trials and meta-analyses.

Table note: Relative risk above 1 indicates increased risk. Relative risk below 1 indicates decreased risk.

Study	Study Population (number of participants)	Follow-up (months)	Relative Risk of a Breast Cancer Recurrence Among Women Who Used MHT after Breast Cancer Compared to Those Who Did Not, RR (95% CI)
Randomized controlled trials
Holmberg et al. [1]	442	48	Local recurrence, metastasis or cancer in the opposite breast: 2.2 (1.0-5.1)
Fahlén et al. [2]	378	130	Local recurrence: 0.8 (0.3-1.7) Metastasis: 1.0 (0.5-2.3) Cancer in the opposite breast: 3.3 (1.2-10.9)
Meta-analyses
Poggio et al. [3]	4 randomized controlled trials		Local recurrence, metastasis or cancer in the opposite breast: 1.46 (1.12-1.91)
Mudhune et al. [4]	4 randomized controlled trials		Local recurrence, metastasis or cancer in the opposite breast: 1.46 (1.20-1.77)

 

References

1. Holmberg L, Iverson OE, Rudenstam CM, et al., for the HABITS Study Group. Increased risk of recurrence after hormone replacement therapy in breast cancer survivors. J Natl Cancer Inst. 100(7):475-82, 2008.
2. Fahlén M, Fornander T, Johansson H, et al. Hormone replacement therapy after breast cancer: 10 year follow up of the Stockholm randomised trial. Eur J Cancer. 49(1):52-9, 2013.
3. Poggio F, Del Mastro L, Bruzzone M, et al. Safety of systemic hormone replacement therapy in breast cancer survivors: a systematic review and meta-analysis. Breast Cancer Res Treat. 191(2):269-275, 2022.
4. Mudhune GH, Armour M, McBride KA. Safety of menopausal hormone therapy in breast cancer survivors older than fifty at diagnosis: a systematic review and meta-analysis. Breast. 47:43-55, 2019.

Updated 04/19/23