Re: CYP2D6: my oncologist said it's bunk. It can help them understand whether we metabolize tamoxifen at all, but it's not a good predictor of whether it reduces recurrence--for that, she goes back to original pathology. She's a good one and I trust her, for what it's worth.

The nurses have all said that side effects CAN be a good sign. That is, the more miserable we are from tamoxifen, the greater chance that it's doing its job. Menopausal symptoms (hot flashes, night sweats, etc.) are therefore reassuring, at least in my mind.

I augment with supplements, too. Vitamin D is a big one for reducing the risk of recurrence; my PCP tests my vitamin D every six months.

The key information in here though is the following paragraph:

"A British study showed that after 12 to 18 months use (of tamoxifen), women showing a minimum of 10% reduction in breast density (easily determined via mammogram) reduced their risk of developing breast cancer by 66%. But women who didn’t show a decrease in breast density received no benefit from the drug."
- See more at: http://www.healthcentral.com/breast-cancer/c/78...tamoxifen-work/#sthash.S1sMlxcK.dpuf

Premeno, also. Hot flashes waxed, then waned, with no apparent correlation to my estrogen status- Im presently- two years out from chemo and resultant cessation of my period- without hot flashes, skin and all bits dried up, yet still perimenopause, according to labs. There's conflicting ideas about wether there's a correlation between side effects and success of Tam. I tend to think not.

((Hug))

You might be one of the lucky few who gets no hot flashes on Tamoxifen. It doesn't make estrogen go away; it binds with estrogen receptors (in bones, liver, and--importantly--cancer cells) so that the estrogen CAN'T bond there.

If you're concerned, you can ask your doctor for a blood test; they can measure your estrogen level to see what's going on. My doctor won't do it; she's convinced by my hot flashes (which are horrendous, especially at night) that it's working. :)

My diagnosis was IDC, ER/PR + and Her2 -, stage IV, I was 36 with regular cycles. After my first chemo round my cycle never returned. I was on Tomoxifen for 7 years. It was strongly recomended that my overies be removed. I had no shots or medicine to stop the overies from working and never removed them. This is just my experience. Iwould take the time to make a follow up appointment with your oncologist if what you are experiencing is worrisome. They may have to up the dose or switch the medication or treatment plan altogether. It's good to always have an open dialogue with the doctor. I wish you all the best.