American researchers have suggested that oestrogen creams may improve survival rates, despite previous fears they could stimulate cancer cell growth.
This after their recent study showing that the creams, commonly used to alleviate menopause symptoms, are not only safe for older women diagnosed with breast cancer, but may also correlate with increased survival rates.
The research – led by a team from the University of Arizona, and presented recently at the American Society of Clinical Oncology (ASCO) congress in Chicago – indicated that postmenopausal breast cancer survivors who used these hormone creams experienced a reduced risk of disease progression, recurrence, or death.
These findings challenge previous concerns that the creams could stimulate the growth of breast cancer cells that rely on hormones, reports The Independent.
Vaginal oestrogen creams are frequently used to treat menopause symptoms such as vaginal dryness, discomfort and pain during intercourse. But because of previous concerns, many breast cancer survivors avoid these treatments.
The researchers reviewed national database records on 18 620 female breast cancer patients aged 65 and older who were diagnosed between 2010-2017, including 800, who used vaginal oestrogen creams.
After accounting for race, cancer stage, treatments and other factors, the researchers saw a statistically significant increase in overall survival among patients who used vaginal oestrogen.
The cream users also had a significant increase in breast cancer-specific survival, the interval from diagnosis to death from breast cancer.
On average, oestrogen cream users had a 47% lower risk of dying from breast cancer and a 44% lower risk of death from any cause during the study period, compared with non-users.
Even in patients whose tumours were known to use hormones for growth, oestrogen cream use was associated with a 38% lower risk of death from any cause.
Users with hormone-positive breast cancer also had a lower risk of death from breast cancer, but that difference was not statistically significant.
Use of the creams for more than seven years appeared to confer an additional survival benefit.
“These findings add to a rising contemporary paradigm shift that local hormone therapy is not associated with increased risk to overall or breast cancer-specific survival, which has important clinical implications,” the researchers said.
Study details
Use of local oestrogen therapy among breast cancer patients in SEER-MHOS database
Olivia Mitchel, Paul Hsu, and Jennifer Erdrich
Published in Journal of Clinical Oncology on 28 May 2025
Abstract
Background
Anti-hormonal therapy with tamoxifen or aromatase inhibitors is a key component in the treatment of hormone receptor-positive breast cancers. One of the adverse effects of this type of therapy is genitourinary syndrome of menopause, which may be treated with vaginal oestrogen. It remains unclear whether local vaginal oestrogen use carries any increased risk of recurrence or mortality in patients with a history of breast cancer. This has led to conflicting advice in the clinical setting and potentially unnecessary avoidance of hormone-based products that could possibly provide women symptomatic relief. Further exploration of the relationship between local oestrogen therapy and breast cancer outcomes is warranted.
Methods
A retrospective cohort study of 18,620 female breast cancer patients ≥ 65 years of age diagnosed between 2010-2017 in the SEER-MHOS registry was performed, comparing the breast cancer patients who used local vaginal oestrogen (n=800) to those who did not (n=17,820), to assess whether local vaginal oestrogen exposure was associated with any difference in overall survival as a primary outcome. Breast cancer specific survival was analysed as a secondary outcome. Missing data was excluded by complete case analysis. Wilcoxon rank-sum tests were performed to compare continuous variables, Chi-square tests to compare categorical variables, Kaplan-Meier estimation to summarise overall survival, and sub-distribution hazard regression was performed to evaluate breast cancer specific survival by group. Multivariate regression models controlled for age, race, cancer stage, treatment (i.e. surgery, radiation, anti-hormonal therapy), and year of diagnosis. The research protocol was approved by our Scientific Review Committee and submitted for IRB approval.
Results
There was a statistically significant increase in overall survival (HR=0.56, p<0.0001) as well as breast cancer-specific survival (HR=0.53, p=0.014) among breast cancer patients who used vaginal oestrogen compared to those who did not. Among those who used vaginal oestrogen, there was a statistically significant increase in overall survival for those with a duration of use >7 years (median duration of use) compared to those with a duration of use <7 years (HR=0.01, p<0.0001). Subset analysis restricted to patients with hormone positive breast cancer showed a statistically significant increase in overall survival for those who used vaginal oestrogen compared to those who did not (HR=0.62, p=0.0007), and a non-significant increase in breast cancer specific survival (HR=0.62, p=0.08).
Conclusions
The use of vaginal oestrogen among this SEER-MHOS cohort of breast cancer patients showed improved survival outcomes. These findings add to a rising contemporary paradigm shift that local hormone therapy is not associated with increased risk to overall or breast cancer specific survival, which has important clinical implications.
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