The E-string is a diaphragm-like device that is inserted into the cervix. The device, which lasts 3 months, releases low levels of estrogen into your vagina.
Opinions vary about the safety of the E-string for breast cancer survivors. Some doctors feel that the estrogen released remains localized and, therefore, will not cause any problems for breast cancer survivors. However, other doctors think that the estrogen released can get into your bloodstream and increase your risk of cancer recurrence. If you are considering using an E-string, be sure to discuss it first with your doctor.