Seeking others who got cancer while taking tamoxifen

sharon0706

Because of a strong family history, I've been taking tamoxifen preventatively for ten years. I got cancer anyway, and I seem to be a bit of a medical anomaly. Has anyone else had this experience? Looking forward to connecting.

Beesie

I am not in your situation and hopefully others who are respond to your post, but I wanted to comment that I don't think you are a medical anomaly, although you are rare. There is a difference.

For high risk patients, Tamoxifen has been shown in various studies to reduce the risk of a primary breast cancer by anywhere from 40% to about 70%, depending on the study. The average is around 50%, I think. That's a good reduction in risk, but it means that 1/2 of the high risk patients taking Tamoxifen will nevertheless be diagnosed with breast cancer.

The reason you may seen like an anomaly is because the overall numbers are low. "High Risk" is generally considered anyone with 0.5% risk per year or higher. So if you take 1000 women who all have a 0.5% risk per year, over 10 years the breast cancer risk for each woman will be 5%. This means that overall 50 of the 1000 women (5%) would be expected to develop breast cancer during this 10 year period. If this number is reduced by half because all 1000 of the women take Tamoxifen, it means that 25 women will have avoided a breast cancer diagnosis, but 25 women will have been diagnosed, despite taking Tamoxifen. Of course, if over a 10 year period you are looking for 25 women out of 1000, or in aggregate, 2.5% of all high risk patients who take Tamoxifen, any one doctor or hospital might only see one or two patients.

So it is the rare patient who fits this profile, but it's not an anomaly that someone who is high risk taking Tamoxifen would develop breast cancer - because that happens to about 1/2 of the women who take Tamoxifen because they are high risk. That probably doesn't make you feel any better, since you are dealing with a breast cancer diagnosis, but at least you know that you aren't alone in having this happen - even if within this relatively small community, you don't find many others who share your experience.

RebeccaA

I was diagnosed in June with a new primary breast cancer while on Tamoxifen, which I had been taking since 2014. I underwent a mastectomy and just had my reconstruction done this week. Fortunately, the new cancer was caught early, unlike my first cancer. My lymph nodes were clear and I did not need chemo or radiation this time. My oncologist took me off Tamoxifen upon the new diagnosis. The new cancer was ER-positive; my first was triple positive. I started Letrozole in August.

sharon0706

Hi Beesie. Thank you for your reply. I appreciate your perspective and your expertise on the topic. Take care.

Tmh0921

I was diagnosed with a new primary highly ER+/PR+ tumor last year while on Tamoxifen. Clearly, given the hormone receptor status Tamoxifen failed me. When I finished chemo, my MO suppressed my ovaries and switched me to an AI (Letrozole).

Blackhawk41

Hi Tmh0921, I was diagnosed on my right side 2 years after my first diagnosis (er/pr+) while taking Tamoxifen. Thankfully it was caught early (and only by an MRI).I had a lumpectomy, lymph nodes were clear, and 19 radiation treatments. I was then put on Lupron in hopes to get me on an AI. I quit Lupron 3 months later because the side effects were brutal! I’m back on Tamoxifen and better but I’ve noticed an increase in pain and swelling if I eat too many carbs. I tolerated it well when I was initially put on it, but I was also pretty low carb during that time. Basically I’ve had to manage my food to stave off side effects and it seems to work for me. I’ve been genetically tested and came back negative on everything. I do have a family history on both sides.