Hormone therapy (HT) can be used safely to manage menopausal symptoms in women who have undergone treatment for nonserous epithelial ovarian cancer, a retrospective study suggests. The study showed no reduction in overall survival with HT use in the entire study population, and it appears to positively influence disease-free survival among younger women.
The findings, published online April 4 and in the May issue of Obstetrics Gynecology, should reassure physicians who are reluctant to prescribe HT in these patients out of concern it might increase the risk for recurrence and reduce survival.
"The use of HT to treat these symptoms can significantly improve the quality of life of cancer survivors. According to the results of our study, combined with the evidence in the literature, HT may be considered in survivors of nonserous epithelial ovarian cancer who experience menopausal symptoms shortly after treatment," write Laura Power, MD, from the Department of Obstetrics, the Department of Gynecology and Reproductive Sciences, and the Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, Canada, and colleagues.
The researchers compared overall and disease-free survival among women who received HT with those of women who had not received HT. All the women had had prior surgery, chemotherapy, or radiation for nonserous epithelial ovarian cancer.
Using data from the Manitoba Cancer Registry, the researchers identified a cohort of 357 women (median age, 57.8 years) with known nonserous epithelial ovarian, fallopian tube, or primary peritoneal cancer between 1995 and 2010. Of those, 94 women received HT after treatment and 263 did not.
The researchers split the cohort into two groups — women younger than 55 years (n = 158) and those aged 55 years or older (n = 199) — to assess the influence of age on survival between HT- and non-HT-treated women. In the younger group, 74 women were treated with hormones and 84 were not. In the older group, 20 women received hormones and 179 did not.
For women with more than 1 year of HT use, the median duration of use was 4.76 years for those younger than 55 years and 4.04 years for those older than 55 years. The authors note that because of the Women's Health Initiative results, women in their study were more likely to receive HT before 2002.
Among women younger than 55 years who started HT 6 months after cancer treatment, 90.9% were alive at 3 years compared with 78.5% of the women who did not use HT (hazard ratio [HR], 0.410; 95% confidence interval [CI], 0.19 - 0.89; P = .023). However, in a multivariate analysis that controlled for disease stage and chemotherapy, overall survival did not differ between the two groups.
In contrast, HT use was associated with improved disease-free survival in this younger patient group in both the univariate and multivariable models compared with non-HT use (HR, 0.339 [95% CI, 0.17 - 0.69; P = .003]; adjusted HR, 0.354 [95% CI, 0.17 - 0.74, P = .006]).
Among patients aged 55 years and older, the authors saw no difference in overall (adjusted HR, 0.851; 95% CI, 0.43 - 1.68; P = .641) or disease-free survival (adjusted HR, 0.949; 95% CI, 0.50 - 1.80; P = .872) associated with HT use.
In a time-varying Cox regression model designed to investigate any association with duration of hormone use after adjusting for International Federation of Gynecology and Obstetrics stage and chemotherapy use, Dr Power and colleagues found that when HT was used longer than 12 months, disease-free survival improved in women younger than 55 years, with a hazard ratio of 0.212.
"According to the time-varying Cox regression model, HT use for any duration among women older than 55 years of age was not associated with significant differences with respect to overall and disease-free survival," the authors write.
Although the study is limited by its retrospective design and small sample size, one of its strengths is its sole focus on nonserous epithelial ovarian cancer, "which is crucial because these histologies are linked to hormone stimulation and are associated with longer survival," the authors write. "These are the women who might benefit most from HT but who are also at highest theoretical risk of recurrence as a result of exposure to hormones. We found that these women may instead actually benefit from HT use."
Together with published evidence indicating that HT improves the quality of life in healthy postmenopausal women by reducing the vasomotor symptoms of menopause, the current findings suggest HT "may be considered in survivors of nonserous epithelial ovarian cancer who experience menopausal symptoms shortly after treatment."
This study was supported by the Winnipeg HSC Medical Staff Council Award. The authors have disclosed no relevant financial relationships.