I was diagnosed with GCT in 1987 when I was 30. Well encapsulated. All reproductive system organs surgically removed. No other treatment. No recurrence (yet). I was on estrogen to help prevent osteoporosis, hormone imbalance, etc. until just this year. It used to be the gold standard after having your ovaries removed. I was told by many a gyno I should be on it the rest of my life. They used to think it was beneficial for your heart too, but that is now disproved. Then all the negative estrogen/progesterone studies were released in 2002 with the results being that they may promote breast cancer. There is still a lot of debate about this. Keep in mind those studies were on the combo, not estrogen alone. I suggest you do some research on this topic, talk to your docs about it & make your own personal decision. A lot of women are still taking HRT today because of the benefits. A lot of women discontinued HRT after the studies.
Now I'm having breast cancer issues so was just weened off of estrogen. I'm waiting on a second biopsy report, but there's a good chance I'll take Evista instead. My estrogen use could have been a double edged sword, but there's no real proof of that. I do believe the estrogen helped my bones all those years. However, there are other meds available today, Fosomax, Boneva, etc. for osteoporosis. Estrogen has good anti-aging effects & prevents hot flashes. There is a lower dose available today, .03mg compared to the older .625mg.
Good luck reaching a decision.