How can chemotherapy or radiation therapy cause early menopause?

Chemotherapy and radiation therapy can induce early or premature menopause by incidentally damaging or destroying the ovaries.1

In the case of chemotherapy, the chemical agents used to destroy cancerous cells can also affect normal, healthy cells, which may lead to the loss of ovarian function. Similarly, radiation therapy—particularly when directed at the pelvic region—can cause damage to the ovaries as a side effect of the treatment. When these therapies compromise the ovaries, they disrupt the production of estrogen and the maturation of follicles, resulting in the permanent cessation of menstruation and the onset of menopause.21