b7edcfba___We_Can_Help___LIVESTRONG_org__Pros
Low-dose vaginal estrogen replacement (such as Estring, Vagifem) [Cons] Some oncologists still worry about breast cancer survivors using these products. A small study found that some women using suppositories still had levels of estrogen in their blood high enough to interfere with the benefits of aromatase inhibitors. [Pros] 
The Estring releases a small dose of hormone over three months. The Vagifem suppository is used a couple of times a week. Both Estring and Vagifem produce a low dose of estrogen. This is considered to be helpful treating vaginal dryness with very little hormone released into the bloodstream. Generally thought to be safer than pills, patches, or creams.
Female Sexual Health After Cancer | We Can Help | LIVESTRONG.org
Pros