Incidence of ovarian function recovery in women over 40 with chemotherapy induced amenorrhea

This study investigated ovarian function recovery (OFR) after chemotherapy-induced amenorrhea (absence of menstruation) in women aged 40-49 after 2 years of aromatase inhibitor (AI) therapy. The study concluded that a large number of women with chemotherapy-induced amenorrhea recover ovarian function during AI therapy. 

Including an AI in treatment is part of the standard care for postmenopausal women with hormone receptor (HR)-positive BC. HR-positive breast cancer depends on the hormones estrogen or progesterone for growth. AIs can  reduce estrogen levels by up to 98%. This is extremely beneficial in restricting the growth of hormone receptor-positive breast cancer cells.

In premenopausal women however, the use of AIs can cause a negative feedback loop which leads to the over-production of estrogen in the body. This can encourage the growth of breast cancer cells. Some women stop menstruating due to chemotherapy treatments. The effects of AI therapy in these women are not clear.

This study analyzed 173 patients between the ages of 40 and 49 with HR-positive breast cancer. Patients were premenopausal at diagnosis and had stopped menstruating during chemotherapy. The patients were split into two groups: aged 45-49 and aged 40-44.

Patients had previously been treated with tamoxifen (Novladex) for up to a year prior to the study and received 2.5 mg of letrozole (Femara) daily for up to 2 years from the point of enrollment. Levels of follicle stimulating hormone (FSH) and serum estradiol (E2) were measured at enrollment and after 2 years.

A total of 39% of patients regained ovarian function. 6% resumed menstruation. 32% developed premenopausal levels of serum estrogen but not did resume menstruation. Age less than 45 years was found to be predictive of OFR.

The study concluded that a large number of women with chemotherapy-induced amenorrhea recover ovarian function during AI therapy. The authors suggested that women with intact ovaries who cease menstruation in chemotherapy should not undergo AI therapy until after the age of natural menopause.

The study used a relatively small group of subjects, meaning the results may not be generalizable to more diverse patient groups. Further, the authors acknowledge that the reference levels used in the study may be inaccurate.

Discuss the pros and cons of AI therapy with your doctor.