I'm coming up on my last year on tamoxifen. I often wonder if it would be beneficial to me to begin taking an aromatase inhibitor following my five years of tamoxifen. According to an article published in the journal Cancer, premenopausal women with breast cancer that has spread to at least four lymph nodes received the most benefit from aromatase inhibitors following treatment with tamoxifen. Postmenopausal women with cancer that has spread to three or less nodes only seem to get a 1-2 percent benefit from the addition of an aromatase inhibitor following tamoxifen.

I don't seem to fit in either category since I had premenopausal breast cancer with less than four lymph nodes positive. I also thought that if you are premenopausal that aromatase inhibitors were not beneficial at all and only postmenopausal women were able to take these drugs.

Aromatase inhibitors work by reducing the amount of estrogen your body makes. Your adrenal glands produce a substance called androstenedione, which gets converted into estrogen in tissues such as fat and muscle. The conversion requires the enzyme called aromatase. Aromatase inhibitors stop the conversion of androstenedione to estrogen. However, if your ovaries are still functioning then the body still will have estrogen that can help cancer to grow and the aromatase inhibitors will not stop the estrogen production of the ovaries.

The study that was done concluded - it appears that women who are premenopausal and those whose cancer has spread to four or more lymph nodes would derive greater benefit from the addition of aromatase agents following tamoxifen.

I am assuming that they mean if these premenopausal women are then put into a postmenopausal state, either happening by chemotherapy or shutting down the ovaries by injection or oophorectomy.

This is a confusing article that doesn't seem to make sense. Any insights?