Safety and Value of the Estring
As some of you know, the estring (estradiol vaginal ring) is a device sometimes prescribed to help with moderate to severe vaginal symptoms after menopause. This translates to treatment for vaginal dryness and discomfort/pain with intercourse (and sometimes just in the course of normal living). Since the estring works by slowly releasing estrogen directly into vaginal tissues, there are concerns about safety for women who have been treated for breast cancer, especially for estrogen positive breast cancer.
Very honestly, not so much is known about its' efficacy and safety, and the recommendation has always been "talk with your doctor". It has been, and really continues to be, a personal decision based on one woman's cancer experience as well as her quality of life issues. I have known women who used estrings and found some relief, and others who were told by their oncologists that it would not be wise.
JAMA Oncology has just published the first study to look at the safety and value of the estring for post menopausal women who are taking AIs. The conclusions are not so straightforward, so more research needs to be done, and this continues to be an "ask your doctor" situation.
Here is the abstract and a link to read more:
Vaginal Testosterone Cream vs Estradiol Vaginal Ring
for Vaginal Dryness or Decreased Libido inWomen Receiving
Aromatase Inhibitors for Early-Stage Breast Cancer
A Randomized Clinical Trial
Michelle E. Melisko, MD; Mindy E. Goldman, MD; Jimmy Hwang, PhD; Amy De Luca, BA; Sally Fang, BA;
Laura J. Esserman, MD; Amy J. Chien, MD; JohnW. Park, MD; Hope S. Rugo,MD
IMPORTANCE Aromatase inhibitors (AI) are associated with significant urogenital atrophy,
affecting quality of life and drug compliance.
OBJECTIVE To evaluate safety of intravaginal testosterone cream (IVT) or an
estradiol-releasing vaginal ring (7.5 μg/d) in patients with early-stage breast cancer (BC)
receiving an AI. Intervention was considered unsafe if more than 25%of patients had
persistent elevation in estradiol (E2), defined as E2 greater than 10 pg/mL (to convert to
pmol/L, multiply by 3.671) and at least 10 pg/mL above baseline after treatment initiation
on 2 consecutive tests at least 2 weeks apart.
DESIGN, SETTING, AND PARTICIPANTS Postmenopausal (PM)women with hormone receptor
(HR)–positive stage I to III BC taking AIs with self-reported vaginal dryness, dyspareunia, or
decreased libido were randomized to 12 weeks of IVT or an estradiol vaginal ring. Estradiol
was measured at baseline and weeks 4 and 12 using a commercially available liquid
chromatography and tandem mass spectrometry assay; follicle-stimulating hormone levels
were measured at baseline and week 4. Gynecologic examinations and sexual quality-of-life
questionnaires were completed at baseline and week 12. This randomized noncomparative
design allowed safety evaluation of 2 interventions concurrently in the same population of
patients, reducing the possibility of E2 assay variability over time and between the 2
MAIN OUTCOMES AND MEASURES The primary objective of this trial was to evaluate safety of
IVT or an estradiol vaginal ring in patients with early-stage BC receiving an AI; secondary
objectives included evaluation of adverse events, changes in sexual quality of life using the
Cancer Rehabilitation Evaluation System sexuality subscales, changes in vaginal atrophy using
a validated 4-point scale, and comparison of E2 levels.
RESULTS Overall, 76 women signed consent (mean [range] age, 56 [37-78] years), 75 started
treatment, and 69 completed 12 weeks of treatment. Mean (range) baseline E2 was 20 (<2 to
127) pg/mL. At baseline, E2 was above the postmenopausal range (>10 pg/mL) in 28 of 76
women (37%). Persistent E2 elevation was observed in none with a vaginal ring and in 4 of
34 women (12%) with IVT. Transient E2 elevation was seen in 4 of 35 (11%) with a vaginal ring
and in 4 of 34 (12%) with IVT. Vaginal atrophy and sexual interest and dysfunction improved
for all patients.
CONCLUSIONS AND RELEVANCE In PM women with early-stage BC receiving AIs, treatment
with a vaginal ring or IVT over 12 weeks met the primary safety end point. Baseline elevation
in E2 was common and complicates this assessment. Vaginal atrophy, sexual interest, and
sexual dysfunction were improved. Further study is required to understand E2 variability in
TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00698035
Read more: http://jamanetwork.com/pdfaccess.ashx?url=/data/journals/oncology/936096/