Hysterectomies are quite common. In fact, more than 30% of women in the U.S. age 50 or older have had one.

That operation may disrupt hormones or even cause a woman to go into menopause.

Fortunately, menopause symptoms can be alleviated with hormone therapy, which is currently acknowledged to be safe to take for at least 10 years after your last period — although there is still concern about an increased risk for breast cancer.

For women without a uterus, bioidentical estrogen alone can be used, and randomized studies have found that it actually decreases the risk of breast cancer.

Now an observational study suggests that staying on estrogen-only replacement for up to 20 years may be a safe, smart move.

Researchers followed 51 women who had hysterectomies along with removal of their ovaries and fallopian tubes and monitored their health for 20 years as they used a transdermal estradiol patch. They showed improved vertebrae density, increases in good HDL cholesterol, and decreases in bad LDL cholesterol.

In addition, the women experienced sustained decreases in hot flashes; insomnia; muscle, joint, and back pain; vaginal dryness; and urological symptoms.

More good news: Only one 60-year-old woman developed breast cancer (less than the three anticipated due to the age and size of the group). The researchers concluded "the use of long-term hormone therapy was not associated with breast cancer in our cohort."

If you've had a hysterectomy and are interested in long-term hormone therapy, talk to your doctor — and push him or her to look at the latest data.