Would you prescribe vaginal estrogen cream for vaginal dryness to a patient in her 40s with a history of stage IA granulosa cell tumor?

Systemic serum absorption after use of low-dose vaginal estradiol inserts (such as 10 mcg estradiol tablet or 7.5 mcg/day estradiol ring) is very low. One study (Notelovitz et al., PMID 12039110) showed that baseline serum estradiol levels were 7-8 pg/ml in postmenopausal women. With the use of a 10 mcg vaginal insert, serum levels were noted between 11 and 23 pg/ml at 24 hours. Another study (Archer et al., PMID 28002201), used 4, 10, or 25 mcg doses daily for 2 weeks, then twice weekly for 10 weeks with the 4 mcg dose. No difference was noted in serum estradiol level. The 10 mcg dose showed an increase on day 1 to 10.9 pg/ml (vs 6.6 in placebo) but no difference by day 14.

A multi-center trial reported in 2020 examined vaginal estrogen use in 244 women with endometrial, cervical, ovarian, and low malignant potential tumors (Chambers et al., PMID 32075898). The authors concluded that adverse outcomes, including recurrence and thromboembolism, were infrequent, making vaginal estrogen a safe option for women who were disease-free and not undergoing active treatment.  

I would feel safe using low-dose vaginal estrogen therapy for women who are disease-free and not undergoing active treatment, though I would start at the lowest dose.