Is the use of menopause hormone therapy safe in women who have been treated for breast cancer?
An increased risk of breast cancer recurrence has been reported in a number of RCTs examining the use of menopause hormone therapy for menopausal symptoms. Tibolone was shown to significantly increase the risk of breast cancer recurrence compared with placebo (HR 1.40; 95% CI 1.14, 1.17),34, 35 while oestrogen was shown to significantly increase the risk of breast cancer events (HR 3.5; 95% CI 1.5, 8.1).90 Another study showed no increase in breast cancer recurrence with oestrogen compared with no menopause hormone therapy; however, the trial was stopped early due to an increased hazard of breast cancer.91
The use of menopause hormone therapy to treat menopausal symptoms in women who have been treated for breast cancer should generally be avoided, and be limited to cases where symptoms are resistant to treatment and the quality of life benefit outweighs the potential risk. Informed consent should be sought from the woman, and the decision to use MHT should be made in conjunction with the treating oncology team and counselling regarding the potential increased risk of breast cancer recurrence.3
Is the use of testosterone effective and safe in women who have been treated for breast cancer?
Based on the findings of the supplementary systematic review conducted for this guideline, the use of testosterone with oestrogen may have a beneficial effect on sexual functioning and no effect on vasomotor symptoms in the general female menopausal population, but may also affect lipid profiles and increase the incidence of acne and hirsutism.44, 87 There was some evidence that testosterone had a beneficial effect on personal distress, although the authors noted that the quality of the evidence for that outcome was imprecise and at risk of bias.87 An RCT conducted in women who had survived cancer (not limited to breast) who had decreased libido found no benefit of transdermal testosterone over placebo.92
Thus, the effectiveness and safety of testosterone for the treatment of menopausal symptoms in women who have been treated for breast cancer are highly uncertain. It should also be noted that testosterone is not approved by the Therapeutic Goods Administration (TGA) for the treatment of menopausal symptoms.
Is the use of compounded hormones (‘bioidentical’ hormones) hormones effective and safe in women who have been treated for breast cancer?
A recent cross-sectional study has estimated that 6% of Australian women aged 50–69 years have used compounded hormones at some time, with 2% being current.93 A systematic review of studies in the general female postmenopausal population found that two RCTs showed no benefit of compounded hormone (a standardised, manufactured progesterone cream) over placebo when vasomotor symptoms were measured using a validated scale, while another found that a compounded progesterone cream (which could not be replicated) significantly improved self-reported severity of vasomotor symptoms.42 Safety data from the included studies was limited; vaginal spotting was reported in a small number of patients in two RCTs while a third RCT noted there was no significant difference between treatment and placebo for headaches or vaginal spotting.42 Compounded hormones are systemically absorbed and may contain high levels of sex steroids which may increase the risk of new or recurrent breast cancer. It should be noted that compounded hormones have not been studied in women who have received treatment for breast cancer, and compounded hormones are not registered with the TGA.
Is the use of laser therapy for vulvovaginal symptoms effective and safe in women who have been treated for breast cancer?
CO2 laser therapy is an emerging treatment for vulvovaginal atrophy. Preliminary in vitro and ex vivo studies have found that use of laser therapy can result in the remodelling of vaginal tissue. 94, 95 To date, only a small number of observational studies have been performed using CO2 laser therapy in post-menopausal women. These studies have reported significant improvements in vulvovaginal symptoms, sexual function and quality of life over up to 12 weeks of follow-up.96-98 The results of these studies should be interpreted with caution as they have not included an appropriate control, such as sham laser treatment or active control with hormone treatments, which is necessary to address the substantial placebo response that is common in trials investigating female sexual dysfunction.99 As the studies have been of short duration, they have not established the long-term durability of the effect, or the long-term safety of vaginal laser therapy. In addition, no studies have been carried out in women with a history of breast cancer. Further research of a higher methodological standard is required to establish the efficacy and safety of laser therapy for the management of vulvovaginal atrophy.