Tamoxifin vs Aromasin

     I am a 3 1/2 year BC survivor.  I have been on Tamoxifin (tamoxifen) for that long. Can you tell me the bad things about Tamoxifin (tamoxifen) that can happen and also is it wise to switch to Aromasin. It is so expensive !!


This discussion is related to Tamoxifin (tamoxifen) side effects.

[Fernando Roque, MD]

Hi.  How old are you? Are you post-menopausal?  Exemestane (Aromasin) and similar drugs called aromatase inhibitors, will only work with women who have already undergone menopause.   If you're in the reproductive age group, Tamoxifen is still your primary option for hormonal treatment.  For post-menopausal women who have breast cancer, and are estrogen receptor (ER) or progesterone receptor (PR) positive, switching from Tamoxifen to Aromasin would confer an advantage in terms of reducing the risk of cancer recurrence.

The most common side effects associated with Tamoxifen are hot flashes, vaginal dryness, nausea and weight gain.  These are less commonly seen with intake of aromatase inhibitors like Aromasin. Women who take Tamoxifen are also at an increased risk (compared with aromatase inhibitors) of developing blood clots which can travel to other organs and cause complications like pulmonary embolism or stroke.  Those taking Aromasin, on the other hand, have an increased risk of developing significant osteoporosis and bone fractures compared with those taking Tamoxifen.

[katarina777]

How do you know if you are post menopausal? I am 49 years old and I was diagnosed with IBC in June of 07. I was not post menopausal. but then, I never had another period after I started the chemotherapy. I also take Tamoxifen since February 08. Does this definitely mean I am post menopausal?

[Fernando Roque, MD]

Hi.  Menopause means that you have permanently stopped menstruating.  Some women stop having menstruation when they start chemotherapy, but this may only be drug-induced and may be temporary.  The menstruation may come back 6 months or even a year after the last session of chemotherapy. The National Comprehensive Cancer Network (NCCN), in their breast cancer guidelines, has issued the following criteria for determining if a woman is likely post-menopausal:

1.  At least 60 years old.

2.  If less than 60 years old, the woman has stopped menstruating for 12 months or more in the absence of chemotherapy, tamoxifen, toremifene or other hormonal treatment to suppress the ovaries, AND blood levels of FSH (follicle stimulating hormone) and estradiol are in the post-menopausal range.

3.  If less than 60 years old and taking tamoxifen or toremifene, the blood levels of FSH (follicle stimulating hormone) and estradiol should be in the post-menopausal range.

So for your case, you should have your blood levels for FSH and estradiol tested. If the levels are low enough, you could be considered as post-menopausal.

[katarina777]

I am sorry if I am mixing up your name, but thought I'd stay consistent. Thank you very much for this information. I'll teach my oncologist. He told me he was not sure, either.