Estrogen Replacement Therapy Safe in Epithelial Ovarian Cancer
Pre- or postmenopausal patients with epithelial ovarian cancer can safely be treated with adjuvant Estrogen Replacement Therapy (ERT), a recent study  reports.
Ovarian cancer is common and we estimate that the number of patients diagnosed with ovarian cancer in Australia (currently 1,300 per year) will still increase over the years. According to Australian government statistics more than 9,000 women diagnosed with ovarian cancer in the last 30 years are alive and well at present.
A large number of postmenopausal women are on ERT to alleviate symptoms that would affect their quality of life. Uncertainty existed whether these women could remain on ERT.
In addition, a significant number of premenopausal women are diagnosed with ovarian cancer every year and gynaecological oncologists are often asked how the issues of hot flushes, coronary artery disease and osteoporosis should be managed.
Retrospective data on ERT in patients diagnosed with ovarian cancer previously suggested a 25% improved survival for those women who received ERT. However, the difference was not statistically significant. However, retrospective data are always fraught with selection bias and definitive conclusions are impossible to draw from retrospective data.
In an ERT trial, a research team led by Rosalind A. Eeles, MD, of the Institute of Cancer Research in London, investigated if patients with ovarian cancer could safely take ERT to improve severe menopausal symptoms after cancer treatment.
In the study, women with epithelial ovarian cancer of any stage were randomly assigned to receive ERT for 5 years from 1990 to 1995 (75 women) or not receive hormone therapy (control group with 75 women) after ovarian cancer treatment. All patients had been diagnosed within 9 months and 63% were FIGO disease stage III or IV. The median patient age was 59 years and 77% of the patients were postmenopausal. The study assessed 19 years of patient follow-up.
The results are welcoming news for ovarian cancer patients who suffer from menopausal-like symptoms. For women with epithelial ovarian cancer, ERT is associated with improved survival. At data analysis, 81% of all patients had died. The rate of mortality was 71% in the ERT group compared with 91% in the control group (no hormone therapy). Relapse-free survival was also better in the ERT group compared with the control group. In the ERT group the median treatment time was 1.14 years. The majority of deaths in both groups were due to ovarian cancer. Adverse event rates were low and comparable for both groups.
The important message here is that there is no concern about hormone replacement therapy in the context of ovarian cancer. An increasing number of patients with ovarian cancer will survive their disease and as clinicians we need to make sure these women do not simply survive but survive well at a high quality of life.
These results are also extremely similar to results from trials in cervix and uterine cancer. In both trials, patients who were put on ERT by their surgeons did at least equally well (if not better) compared to patients who did not go on ERT.
In my clinical practice, I am cautious about ERT in patents with ovarian cancer that arose in the background of endometriosis (most of clear cell cancers do). It is widely accepted that endometriosis is fuelled by estrogen and I would be inclined to make alternatives to estrogen available for those very few patients. Those alternatives may include Efexor at a dose of 37.5 mg tablets or topical estrogen vaginally that will not be absorbed at large concentrations into the blood stream.
Some of our readers may argue that a relationship between the risk of ovarian cancer development and Hormone Replacement Therapy (HRT) is widely accepted. According to a recent study published in Lancet this year one additional ovarian cancer will develop for every 1000 women who take HRT for 5 years and one extra ovarian cancer death will happen for every 1700 users .
However, the real question is not whether HRT causes ovarian cancer but it is whether the benefits of ERT outweigh the disadvantages in woman diagnosed with ovarian cancer.
In my personal opinion it is debatable whether women diagnosed with ovarian cancer who do not suffer from menopausal symptoms should receive hormone replacement therapy. It seems that this UK study has given us the OK to treat women with ERT as if they did not have ovarian cancer.
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 Eeles RA, Morden JP, Gore M, et al. Adjuvant hormone therapy may improve survival in epithelial ovarian cancer: results of the AHT randomized trial. [published online ahead of print September 18, 2015]. J Clin Oncol. doi: 10.1200/JCO.2015.60.9719.
 Menopausal hormone use and ovarian cancer risk: individual participant meta-analysis of 52 epidemiological studies. Collaborative Group on Epidemiological Studies of Ovarian Cancer; Lancet 2015; 9980:1835 – 1842. DOI: http://dx.doi.org/10.1016/S0140-6736(14)61687-1