Come join others currently navigating treatment in our weekly Zoom Meetup! Register here: Tuesdays, 1pm ET.
Fill Out Your Profile to share more about you. Learn more...

Tamoxifen and Thickened Uterine Lining

BCAE
BCAE Member Posts: 5

Hey all! I've been on Tamoxifen for over 2 years now as a preventive for DCIS. Recently I started having spotting between my periods. During my annual checkup, my ob/gyn ordered a pelvic ultrasound, which came back with thickened uterine lining of 16mm. I just did a biopsy to determine if I have uterine cancer or atypical typical endometrial hyperplasia. (Sigh...I'm so sick of cancer!) I was wondering if anyone else has had this problem. My doctor made it sound like this was unusual, even though it is a known side effect of Tamoxifen. I was also wondering if I stop Tamoxifen whether my uterus will return to normal. I was never totally convinced of the effectiveness of Tamoxifen (the studies didn't seem to have very meaningful data), so I'm ready to stop if it will! But I also declined radiation, so Tamoxifen is my insurance. I'd love to hear your experience!

«13

Comments

  • veeder14
    veeder14 Member Posts: 269
    edited December 2019

    Hi BCEA,

    Tamoxifen gave me a thickened uterine lining of 17 mm in just 4 months on it. I’m post menopausal so probably a different situation than you. So had a hysterectomy before continuing with Tamoxifen even though I was against it. I hope you don’t have cancer from it. Major side effects from Tamoxifen really sucks

  • Euphoriaa
    Euphoriaa Member Posts: 152
    edited December 2019

    Most likely it's a tamoxifen SE. It's reversible if you stop taking it, at least that's what my MO said. Good luck!

  • DorothyB
    DorothyB Member Posts: 143
    edited December 2019

    Agree that it is a side effect. How many mg of tamoxifen are you taking each day? The new standard for DCIS is 5 mg.

    Against medical advice, I am only taking 10 mg / day. I believe that since I am taking less than 20 mg, it will lessen the chance of some of the side effects, but I am still having muscle cramps, hot flashes and very intermittent nausea. I've only been on tamoxifen for 4 1/2 months (and some of that at 12.5 mg / day) and am having my first pelvic exam next week.

  • BCAE
    BCAE Member Posts: 5
    edited December 2019

    Thanks for your responses.

    DorothyB, Yes I had heard of the one study but I wasn't sure how doctors were embracing this low-dose idea...is it the new standard? I live in a major metro area, but I feel like my doctors are more conservative. I am on 20 mg and really haven't suffered much side effects. However, I was also already doing acupuncture before I started taking tamoxifen to mitigate the effects...it had already helped me with a hormone imbalance pre-tamoxifen.

    Euphoriaa Did your MO say the thickening or the atypical hyperplasia is reversible?

  • DorothyB
    DorothyB Member Posts: 143
    edited December 2019

    I'm not sure that it is the new standard, but it is YOUR body and YOUR choice. Do some googling - there seems to have only been one trial focused on this specific issue.

  • flashlight
    flashlight Member Posts: 311
    edited December 2019

    BCAE, I am postmenopausal and had a D&C last August for a thickened Uterine lining caused by Tamoxifen. I didn't have any bleeding/spotting, but the U/S showed a thickened lining and they were unable to do a biopsy in the office. As it turned out the Tamoxifen caused my old fibroid/polyp to grow which gave a false reading about my lining. Unless you go through a D&C, which wasn't terrible, you won't have any answers to this issue. My MO wasn't concerned. I have decided to have a hysterectomy next month. As Dorothy did I decreased my dose to 10mg. I'm still having side effects so it must be working! Good luck to you.

  • BCAE
    BCAE Member Posts: 5
    edited December 2019

    Hey everyone! THANKFULLY! my biopsy came back normal...but now what? Does anyone know if having the thickened lining of the uterus put me at risk for anything else?!? I am supposed to go back to see my ob/gyn in several months to followup, and she is suggesting I discuss with my MO about continued Tamoxifen use...

  • legomaster225
    legomaster225 Member Posts: 356
    edited December 2019

    I had uterine thickening and 2 D&C's in the first 10 months on tamoxifen. No other side effects. My MO switched me to Aromasin as I tested postmenopausal after chemo treatments. I still have minor side effects with the Aromasin -achy joints and insomnia but my uterus is good.

  • crazy_daisy
    crazy_daisy Member Posts: 1
    edited December 2019

    Tamoxifen had major SE's for me. Physical--including uterine thickening--and cognitive. To the point my onc was actually stunned and immediately took me off. Pay close attention to your body, and definitely bring it up before it has a chance to balloon and re-evaluate your risk benefit together. It's been years and I'm not back to normal yet.

  • LowcountryGirl
    LowcountryGirl Member Posts: 26
    edited December 2019

    After 4 months on tamoxifen my uterus thickened and my ovaries were covered in cysts. I insisted on an estradiol test which was 856! Similar to being 6 months pregnant. I flipped out and wanted my ovaries and uterus removed. The onco fought me because the ovaries are good for your bones but I persisted. Four weeks after the hysterectomy/ oopherectomy a very pale gynie onco walked into my room to tell me the pathologis found the beginning stage of uterine cancer in the wall of my uterus. She was stunned. Listen to your bodies, ladies!

  • WC3
    WC3 Member Posts: 658
    edited December 2019

    I have a tickened lining they feel is from the Tamoxifen but I saw a gynecological oncologist and she said it's nothing to worry about unless I start bleeding.

  • DorothyB
    DorothyB Member Posts: 143
    edited December 2019

    I'm having my first ultrasound to check uterus since 2015. I had at least one polyp in 2015 but we didn't do anything about it. Gynecologist said that if the ultrasound shows any polyps, she would remove them since tamoxifen can make them grow.

    She hasn't mentioned hysterectomy.

  • DeeDeeT
    DeeDeeT Member Posts: 17
    edited December 2019

    LowcountryGirl-- thanks for sharing your story. I didn't have to fight my GYN on this, but I am in a very similar situation (very thickened uterus, multiple cysts in both ovaries) and am on the schedule to have my uterus and my ovaries removed. Your story makes me feel even more confident in this decision. I am so happy for you that they removed everything in time and that you listened to your body!

  • wallycat
    wallycat Member Posts: 1,219
    edited December 2019

    I also had a thickened lining. As soon as AIs were found helpful, they switched me. Tamoxifen put me in menopause right away. 2 years later, I had a thicker lining and it turns out it was 3 polyps. B-9.


  • princessbuttercup
    princessbuttercup Member Posts: 159
    edited December 2019

    I have post-menopausal bleeding on tamoxifen, and have been taken off of it temporarily. Pelvic ultrasound showed thickening of the uterine lining, and I'm scheduled for a hysteroscopy soon. My gyn agrees that this med is making me miserable! I can barely walk without pain.


  • DorothyB
    DorothyB Member Posts: 143
    edited December 2019

    I had my baseline pelvic ultrasound last week (after starting Tamoxifen on Aug 1 and am taking 10 mg / day (Med Onc wants me on 20 mg, but . . . ).

    I had an ultrasound in 2015 and it showed a polyp. Gynecologist said if polyp still there, she would "take me to surgery" and remove it.

    Ultrasound showed NO polyp, but three fibroids. Uterine lining is 3 mm.

    Will have annual follow-ups to be sure fibroids aren't growing and lining isn't getting too thick, etc.

    I'm hoping w/ 10 mg along with exercise and diet changes, I won't have any issues.

  • BCAE
    BCAE Member Posts: 5
    edited January 2020

    So I'm getting confused...my ob/gyn is saying that the thickened lining puts me at a higher risk for uterine cancer....and then said it is also a symptom of uterine cancer. Does that mean the thickened lining actually causes it or is just reflective of it. Also, my MO is saying that she is okay if reduce the Tamoxifen to 5 mg since it is preventative. (I think she also doesn't see an issue if I stay at 20 mg.) I guess I'm trying to figure out if the 20mg dosage is worth the risk (if there truly is one) if this is my only negative symptom.

  • flashlight
    flashlight Member Posts: 311
    edited January 2020

    Hi BCAE, Are you postmenopausal? The way I understand it is that the Tamoxifen can cause your uterine lining to thicken and it will also feed fibroids/polyps causing them to grow. Most women past menopause their endometrial lining is around 4mm. Anything over 5mm I was told is abnormal and can cause bleeding/discomfort. Because the lining is thicker it may cause cells to become abnormal leading to cancer. If you are not having your period your lining isn't getting rid of these cells monthly. If you are the thickened lining is irritating causing you to spot. So if your doctor gives you a diagnosis of hyperplasia I would get another opinion on whether you should continue on Tamoxifen. You should go through the D&C to get rid of it.

  • BCAE
    BCAE Member Posts: 5
    edited January 2020

    No, I'm pre-menopausal and was not diagnosed with hyperplasia. But it sounds like you are saying that the thickening lining can actually *cause* cancer for both pre and post menopausal women. I will say that my thickened lining was toward the beginning of my cycle so I think that's why it seemed suspect.

  • flashlight
    flashlight Member Posts: 311
    edited January 2020

    If I'm understanding it right it sounds like you are not shedding enough of your lining during your period and it is still thickened at the start of your cycle. It was a long time ago, but when I was trying to get pregnant I remember that your lining thickens during ovulation about half way through your cycle. My question would then be how thick is my endometrial lining at that time and should I be concerned about the possible increase of abnormal cells growing since I am not getting rid of it during menstruation. I know it is all so confusing. I meet with my Urogynecologist tomorrow and I'm not looking forward to that! but I want the hysterectomy so I can continue on the Tamoxifen for my bone health. Best wishes....

  • rubyredslippers
    rubyredslippers Member Posts: 94
    edited January 2020

    BCAE, I encourage you to read a book called What your doctor may not have told you about Breast Cancer, by Dr. John Lee. He has a lot to say about Tamoxifen that every woman should know. This is very sad.

    “My doctor made it sound like this was unusual, even though it is a known side effect of Tamoxifen.“ Indeed it is, your doctors behaviour is not surprising to me. Please read the book I've mentioned.

  • TaTango
    TaTango Member Posts: 1
    edited January 2020


    Thank you very much for posting the book recommendation; just ordered my copy as I have some decisions to make. I refused tomoxefin after DCIS treatment 6 months ago and Drs. are again encouraging me to go on it. So far I'm declining again but I need to read this book. Thank you!

  • rubyredslippers
    rubyredslippers Member Posts: 94
    edited January 2020

    tatango - it’s important you read it. So glad to hear.


  • flashlight
    flashlight Member Posts: 311
    edited January 2020
    What your doctor may not have told you about Breast Cancer and


    How Hormone Balance Can Help Save Your Life
    by John R. Lee, M.D., David Zava, Ph.D. and Virginia Hopkins
    Warner Books 2002 (410 Pages)

    Just think about what has happened since 2002. Everyone who was diagnosed with BC had to have chemo. There wasn't any staging or BRCA1 or 2, radiation wasn't as safe. TaTango, If you want to decline hormonal therapy that is your prerogative. There is a lot of current information both for and against this treatment online and on this site.

  • rubyredslippers
    rubyredslippers Member Posts: 94
    edited January 2020

    flashlight this isn't about what things were like in 2002, and please stop making outrageous claims like “everyone had to have chemo”. Consent has always been necessary. Facts about tamoxifen are facts. Have you read the book I've referred to?

    We all have the right to read this book, do our own reading and make an informed decision

  • flashlight
    flashlight Member Posts: 311
    edited January 2020

    rubyredslippers, This is a topic about those of us who have accepted Tamoxifen and have experienced a thickened uterine lining. Something you know nothing about because as you stated you declined this treatment. You made your informed decision. Whether or not that contributed to your recurrence is unknown. Anyone can read anything they want and believe what they want. In 18 years there has been more information on Tamoxifen pro/con to digest. BREAST: THE OWNER'S MANUAL by Dr. Kristi Funk; I was just given this book to read.

  • rubyredslippers
    rubyredslippers Member Posts: 94
    edited January 2020

    The title of the thread tells me what it's about

    I'm so glad I know nothing about it, I'm happy with the decision I made. "Weather of not that contributed to your recurrence is unknown" - that's one of the nastiest comments I've heard. But if you think that Tamoxifen will prevent that happening to you then you have nothing to worry about anymore? Reading this thread was interesting. Best of luck to you with Tamoxifen.

  • godisone
    godisone Member Posts: 30
    edited January 2020

    It Is true that the uterine thickeningh due to side effect of tamoxifen is temperorary phenomenon and the thickening discontinues as soon as the drug is discontinued.

  • TripleApositive
    TripleApositive Member Posts: 1
    edited January 2020

    so I got a new oncologist I’m four years post triple positive double mess Secta me anyway I asked him if I could come off tamoxifen and not be on it for 10 years like my first oncologist suggested and he said that there was a test they could do on my original biopsy and that it could show whether or not it would be effective and what the you know percentages were on how long and how much I might actually need so I was all excited to do that and then I got a letter from some company in California that I guess he ordered it from and they’re the only Company that’s doing this evidently so the letter was about finance —insurance does not cover it and they wanted to set up some sort of payment plan with me and you know what I’ve just been hammered for 4 years with different things and I’m just tired of paying for stuff andSo is my husband which is another different matter altogether but anyway so now I don’t know if I need this tamoxifen for 10 years or not ....does anybody know?

  • Sammy3
    Sammy3 Member Posts: 28
    edited January 2020

    HI guys! posted this on a different tamoxifen thread, but then realized it wasn't active so I came here. I have been lurking here for a while, but I have a question for you. I have a D&C scheduled for 1/20. I have been on Tamoxifen since 2016, and also haven't had a period since I started chemo in '15. I am in the gray area (age 48) of "am I in menopause or not" but hormonally I am not. So anyway, per an u/s in November my gyn wanted to biopsy the endometrium (12cm). We have tried 2 in office procedures and none were successful because the cervix was closed. This is why the D&C is scheduled. They gave not much in pre-op education, but I read up a bit and saw that it is common to have a cervical softening agent the day before. Since they didnt mention this, I called to ask & the nurse said "oh we will call you in some Cytotec". I asked if it was self explanatory thinking it was the stuff you put ON your cervix, and she said it was oral. So I guess I am confused. #1 - Since my cervix hasn't been cooperative yet....wouldn't you think they would have talked to me about it? And #2 - Did you guys who did this take oral Cytotec?