Tamoxifen and bleeding

I’ve not been on the forum for months and months, but I’ve just had a visit to my oncologist today and I’m looking for more info - I wondered if any one on here could help?

I’ve been on tamoxifen for 14 months. Since then I’ve had a couple of light periods, but nothing much. 3 weeks ago a had another one after months of nothing, but it has carried on. It’s really light, but the onc says as it’s persistent he wants me to see a gynaecologist who will check to see if the lining of my uterus is swollen and if I’ve got polyps or anything else that might casue bleeding.
He’s told me to stop taking tamox straight away.

Has anyone else had this? Is it a sign of something sinister? He said they may take me off tamox altogether, but as I had DCIS there is no alternative to take. This must have implications for the possibility of cancer returning?

Any comments welcome - reassuring or honestly blunt are fine!

Thank in advance

Anyone had the same?

Hi there I had some abnormal bleeding, it wasn’t heavy but was investigated …I was given a hysteroscopy and the results came back fine. I was told any abnormal bleeding is always checked out. I think they always air on the side of caution ESP when Tamoxifen is involved as it can cause some side effects. Try not to worry too much easy to say I know as I was worried sick. Take Care xxx

Thanks for the reassurance scottdolly. I’ve been looking around the internet (as you do!) and am hopeful that it will be nothing serious. Did you continue taking the tamoxifen after the investigations?
Thanks again

My periods stopped in Aug 2007 on chemo. I started tamoxifen Oct 2007. Then out of the blue I had a period in Aug 2009. I was really worried about it, the GP gave me an urgent referral to investigate it which scared me even more, but now I know that this is standard procedure with any post menopausal bleeding. Nothing sinister was found, the bleeding was put down to the tamoxifen (as it can cause bleeding) but it has never happened again. I was never told to stop taking it.

Hi Susie I did continue taking Tamoxifen…my periods stopped after my second round of chemo also RoadRunner…it was a total surprise when I did bleed again…but all is ok xx

Thanks for your posts. I saw a gynaecologist on Friday and the bleeding is due to a big polyp (4cm) in my uterus, caused by the tamoxifen. I’m glad I know what is going on. I’m having an op on 28th November to have the polyp removed, and a cyst and the ovary to which it is attached.
After they’ve biopsied it all they’ll decide if going back on tamoxifen is advised or not.
I didn’t know tamoxifen could cause polyps, but now I do!
Thanks for your support,

hi, I had exactly the same thing, in fact the polyps was so large it had started to push out through the cervix (sounds horrendous!) but they removed it and biopsied it, and it was totally benign. `I think they can happen quite often.

Hi After 18 months on Tamoxifin the ongologist decided to change me to Arimadex and after a few months, I had a period my first for a year.I was sent for a scan internal and external and the arimidex were stopped straight away and I was put back on Tamoxifin. The results were ok, thank goodness,but it was a very worrying time. I am still on Tamoxifin with no further bleeding at present.I hope all keeps well with you.
Poppy June

Hi Sussex Girl,

I’m in the same boat. I’m 46, this is yr3 on tx for me and I’ve an appt for my 2nd hysteroscopy next month after 2 more bleeds in Aug and Oct this year. One was horrendous, the other really light. Having mentioned it to my onc at my annual checkup last month he immediately referred me to gynae.

I had my 1st hysteroscopy exactly 2 years ago in my 1st yr on tx for exacly the same reason and it was fine, everything benign and no lumps or anything ammiss.

I think, as others have said, it’s routine to refer you to gynae if you bleed on tx because it can (apparently) cause all sorts of problems and they like to check them out as soon as possible.

I don’t think you say how old you are, but apparently (again - I’m no expert)if you’re pre-men then it’s possible to still have cycles but they’re ‘silent’. Occasionally hormonal wobbles cause break-through bleeding which materialises itself as a period. (I think this is what my onc said…)

So, try not to worry, they seem to do this as a matter of course, and hopefully everything will be OK.

Good luck,Bella

This is an interesting and very relevant post for me. I have just come off Tamoxifen after 3 1/2 years and moved onto Aromasin. I was definitely Peri-menopausal before chemo and after Chemo have not had a sniff of a bleed. A month ago I was having a strange clear ‘discharge’ nothing like I had experienced before and then a week ago I started having a bleed. I informed my BC nurse and have an appointment with the oncologist next week….but bizarrely I also have the results of the hormone test that I had been told to do with my GP ‘as routine’ from coming off Tamoxifen and the results have come back saying my hormone levels are in line with ‘ovarian failure’…which I take it means post-menopausal. I’m a bit freaked out and confused by what appears to me to a conflict! Has anyone else experienced this?

Hormone levels aren’t a good indicator of hormonal function especially without a cycle… They fluctuate on a daily basis and even with full periods certain days in your cycle would be consistent with ovarian failure… Always best to get it checked out however you should only be on AIs if you are def post menopausal or having zoladex to prevent your ovaries from working.

AIs rid your body of hormones so the ovaries work very hard trying to produce more if post menopausal unlikely to have bleeding but if pre or perimenopausal can meek them produce high levels of hormones and cause bleeding… They have been used as fertility treatment in premeno ladies.

I too ad bleeding on tamox… Needed a hysteroscopy and d and c and got a mirena put in which helped loads. Some places are not too keen to use mirena but evidence suggests it can protect the uterus from tamox effects.


hi havent posted for a while but would like some info.i am on tamoxifen for 2 years which stopped my periods,had a bleed in october went to see nurse had a smear test results came back this week.results read abnormal cells in cervix borderline i have an appointment for january at the colposcopy clinic for tests and punch biopsy i am feeling anxious.iam 53 had right mx 2years ago followed by seromas i have lymphoedema in right arm.i have just had my 2year all clear breast screening but now have this worry has anybody gone through simalar problem.thanks missmessy

They do not normally refer you for colposcopy for borderline smear unless you have three borderline in a row. I’d imagine somebody is being a tad overcautious and you may find they don’t actually do the biopsy if it all looks normal under the colposcope. Try not to worry about a borderline smear. This isn’t cancer but the would normally want to do 6 monthly smears to keep an eye on it. It often resolves on it’s own and more likely to have abnormal smears if your a smoker. There are 4 stages of pre cancerous changes the cervix and borderline is the mildest changes.

For borderline and cin1 also called mild dyskariosis you would normally only be monitored with six monthly smears. Its only if three were abnormal in a row that you are normally referred to colposcopy.

For cin 2 and 3 also called moderate or severe dyskariosis you are usually referred to colposcopy and may or may not need treatment and usually monitored by the colp unit for a few years.

They cannot tell you it was borderline if it was more serious so try not think they sent being honest as I can imagine this may be what your worrying about after a referral. And in a worse case scenario 95% of cervical cancers treated early are curable. I know there’s no point saying don’t worry but try not to worry too much as borderline smears are pretty common.

Take care

Hello Twinny,

I switched from tamoxifen to Aromasin about a year ago after an ultrasound I had as part of the UKFOCSS study showed thickening of the endometrial lining. I didn’t have any physical symptoms but felt happier switching. My GP then warned me that I might get some bleeding as a result of the switch, although as it turned out I didn’t. She just wanted to warn me so that I didn’t immediately assume the worst!

thank you so much for your reply you have put my mind at ease i have never had a bad smear test result before so i paniced.thanks i got a bit frightened i think we have all been through so much we think the worst,thank you lulu 34 missmessy

just wanted to say i posted dec about tmmoxifen and bleeding and that i had to go and have a colposopy test . well i went this morning to new cross and had the colposcopy plus biopsy done i have results in three weeks.thanks lulu34 for the advice you gave me it did stop me worrying so much .the doctor said today that tamoxifen can do this to to the cells and that i would probaley need just monitoring and that the cells could go back normal themselves but i will know more when results come back thanks again missmessy

Glad your appt went ok… Good luck with the results I’ll be keeping my fingers crossed for good news.


Haven’t been on here for ages but was interested to read this thread. I’m 3yrs post dx and at 47 was peri menopausal at dx, chemo stopped periods althogether then I had a year of Zoladex. Now 3yrs on I have had one day of bleeding with bad back cramps and more spots on my face than i had as a teenager! I am on Letrozole so know I need to check it out as I understand not effective if you are having periods. It was a schock to see blood after all this time, I had abnormal smears several years ago which was treated by loop wire and have been fine since. Now waiting for results of smear, a scan and oncology appointment…yep I’m worried all over again, it never ends!

Hi moonshine,
sorry to hear this buddy. Ring me if you want someone to talk to you, don’t panic on your own
Lily x