Women treated for breast cancer after menopause with aromatase inhibitors have very high levels of sexual difficulties, including low interest, insufficient lubrication, and pain with intercourse. It is an important and underestimated problem, say the authors of a study published online in Menopause, the journal of the North American Menopause Society.

The researchers from Orebro University and Uppsala University in Sweden are the first to look at the impact of this type of breast cancer treatment on specific aspects of sexuality in postmenopausal women. Nearly three quarters of these women had insufficient lubrication, more than half (56%) had pain with intercourse, half said their sexual interest was low, and 42% were dissatisfied with their sex life, the study revealed.

These percentages were far higher than for postmenopausal women who were not being treated for breast cancer. And although women taking tamoxifen for breast cancer also had low sexual interest and more pain with intercourse, they had significantly fewer difficulties than women taking aromatase inhibitors.

Aromatase inhibitors, which block formation of estrogen from other hormones in the body, may offer advantages in terms of preventing breast cancer recurrence and possibly in increasing survival, so they may be used more in the future. Unfortunately, effective treatment options for their sexual side effects are lacking, because too much estrogen may be absorbed from vaginal estrogen treatments, the authors pointed out. They called for more intensive study of the causes and impact of these side effects so we can improve breast cancer survivors' quality of life in the future.