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Dangers of Tamoxifen: Tell your story with the drug

Posts: 1
Joined: Nov 2011

Hi everyone,

This year my mom developed breast cancer and the doctor prescribed Tamoxifen. Thankfully her network of friends warned her away from this drug. And as I learned more about it, it made me wonder how many women were taking the drug without fully understanding the extreme risks involved? My mother's doctor glossed over it and from what I hear...that is all too common. Anyway, I'm a journalist. And this has put a fire under my rear to look into this issue. What I've found is disturbing and that's why I'm now on this chat board.

I am doing an investigative story on Tamoxifen. The breast cancer treatment & prevention drug that has been repeatedly found to cause aggressive uterine cancer in women were otherwise cancer-free. In my effort to find why this drug is still on the market as a 'prevention' drug, I need to find women who've used it and developed the harsh side effects listed with the drug.

I need a human face on the problem. As the drug company profits and powerful lobbies work to keep it on the market, I need your help. I don't think the seriousness of the issue impacts people until they understand this could be their mother, sister, aunt, best friend, or even themselves.

That said, is there anyone out there who would be willing to tell their story to me? Awareness is key and your voices make all the difference.

Thanks for your help.

Posts: 5
Joined: Sep 2011


Funny how you brought that up when I was just thinkg the same thing. I would be happy to tell my story.

I was disagnosed with breast cancer in 2005. I had a mastectomy and the right side, 2 lymphnodes were positves It was determiined to be estrogren positive. I had both chemo and radiation. I was then started on Tamoxifin. I was warned at that time, that one of the possible side effects is it could cause another form of cancer but the risk was so small, like 2-3% that the doctor just brused over it. After 2 years on tamoxifin they swithced me to another drug, (something like Aromastin, sorry can't remember the spelling) It was suppose to not have the side effects of Tamoxifin but I did not do very well on that drug, it casued severe bone pain and I was getting to the point I could hardly walk so I quit the drug and went back on Tamoxifin which I thought I was not having any side effects. I was seeing breast cancer doctors for 5 years and no one brought up the possible "other cancer" side effect until I went to my gynecologist in May of 2011 for a routine exaime. She brought it up maybe I shoudl talk to the Breast Cancer doctor about having a hysterecomy because of the tamoxifin link.

I had an appointment with the breast cancer on July 18, 2011 but it was too late. I had started bleeding and had been in menopasue for 5 years. So I was sent back to the gynecologist and had a hysterectormy Aug18,2011 and they found cancer, UPSC. I had a second surgery in Sept to stage the cancer. It was staged as 1A, Grade 3. I had a second opinion and that pathlogist found another even more aggressive cancer as Carcinosarcoma of serous type, grade 3. It is still a very aggressive doctor. The second doctor does feel very strongly that there may be a link between the tamoxifen and the uterine cancer. Some of the other doctors just say it is possible but there could be other causes such as genertic. But I agree with you. I never had much history of cancer in my family. My father died of lung cancer but he smoke Lucky Strikes for 50 years. So here I had breast cancer and then 6 years later uterine cancer. Seems suspecious to me. My question is if the medical field knows there is a link between tamoxifen then why not offer women to have a complete hysterecomy or do other testing if the she post menapose. If the doctors would have offered me a complete hystereomcy 2 years ago I would have agreed and not be in this mess today. I thank God I went in to see the doctor with in weeks the bleeding started so they did catch it early but some women have no symtoms or some let their symptoms go on for months before they seek help for various reason.

I know there are other women on these boards who had breast cancer and uterine cancer but i don't know if their situation is similar but I would be curious too. I know alot of money is poured into breast cancer research and I have 2 daughters that I would not want to see go through what I did. I am hoping with research the progognis and treatment would be much improved. If you need some more information you can always email me. Thanks

I decided to go with chemo and had my first chemo
treatment today. I am home now and not sure how I will tolerate it yet but so far so good.

If you need anything else from you can also email me. I would like to help. Good luck with your project.

Double Whammy's picture
Double Whammy
Posts: 2805
Joined: Jun 2010

I've said this many times, but I'll say it again. Yes, there is a known connection between endometrial and breast cancers. Tamoxifen is ONE of them. And so is simply having one of the cancers. The risk factors for both cancers are the same. It is not unusual for a woman to have both cancers over the course of her lifetime. Mine were diagnosed 4 days apart. Hello? I had not even had an opportunity to take Tamoxifen! There are women on both this board and the breast cancer board who have taken Tamoxifen and later developed endometrial cancer. This is not new news. I wonder, tho, if those women would have developed endometrial cancer anyway had they not been on Tamoxifen . . . I guess we may know someday if the fear of taking Tamoxifen keeps women from taking it and they go on to develop endometrial cancer.


daisy366's picture
Posts: 1493
Joined: Mar 2009

Thank you for doing this research. There are many women here with uterine papillary serous carcinoma UPSC (aggressive and rare and seems to be connected) that took tamoxifen years back. There are several threads here - one is uterine cancer in the Valley. You might check out the names and contact them individually. I just emailed one of them to tell of your interest.

We definitely need to help the medical profession to "connect the dots". Thanks for your help in the process.

Mary Ann

Posts: 86
Joined: Jan 2010

Acouple of points from a somewhat differnt perspective. I have USPC and am now on my 3rd recurrence in 3 years since diagnosis-very similar pattern to Linda P, Daisy and Ro and others. I now have new growth in my lungs. My doctor feels I need a few more months off from cytotoxic chemo as 6 months of Cisplatin/Adriamycin the first half of this year was brutal.I just started tamoxifen to see if we can keep the cancer stable for a few months. If you are doing research, Linda P posted several interesting articles on recent clinical trials where tamoxifen had slowed or stopped growth, even in PR negative where most of earlier success was PR positive. Linda took it herself for about 6 months when she was going through the radioembolism treatment for her liver as she could not take regular chemo during that period. I don't know if there is a correlation between uterine cancer patients developing breast cancer but that might be an interesting area for research. However most articles showed breast cancer patients taking it for years and efficacy for uterine cancer patients seemed to be more short term, 3-7 months.Perhapst that is also a difference.
I did have 2 friends that were advised by their doctors to go on it to prevent recurrence of their breast cancer. Both were fully warned of the potential to develop uterine cancer.One had a hysterrectomy before starting and the other is considering it. They were also told what your earlier writer shared that they had a higher probability of developing uterine cancer to begin with and tamoxifen could increase that.

From my personal perspective, with Stage 4 USPC and three recurrences in 3 years, the last now in all lobes of my lungs, I just hope it works for me-we only have a few more chemo drugs and I would like to wait a few months and let my body recover before the enxt round. All these drugs have risks and the literature on tamoxifen is extensive - what we have to hope is our doctors apprise us fully of the risks, let us choose between the lesser of evils and hopefully advise us of measures that may mitigate the risks, such as my friend who had the prophyklactic hysterrectomy before going on the drug.

Songflower's picture
Posts: 631
Joined: Apr 2009

I took tamoxifen in 2000 after having lobular ER positive breast cancer. In 2009 I developed uterine cancer. I was excercising and developed bleeding and I had not had a period for almost ten years. I knew immediately what it most likely was, cancer.
I took adriamycin,cytoxan and taxol for the breast cancer. I was in a research trial; very up to date. I took tamoxifen for five years and then when the aromatase inhibitors came our way I took them for one and half years. Tamoxifen has been generic for quite a few years so I don't think the problem is greedy drug companies; they are trying to help us
in many ways. In some situations they are trying to make money but the use of tamoxifen is complicated.

But, I went to the Gyn several times. I had ultrasounds and even D and C which did not show cancer. I was told I would not get uterine cancer, it is only 1 in 1000. I talked about hysterectomy but taking tamoxifen was not an indication for hysterectomy. I believe that if a drug has been known to cause a cancer in someone it should be their choice if they want a hysterectomy. Just think, one hysterectomy and I would not have had all of this suffering. Read our pages and you can touch the suffering. I have had chemo for a good 2 1/2 years. Hysterectomy, blood clots in the lung, pleural effusions, removal of spleen, gallbladder and appendix with HIPEC for peritoneal carcinamatosis.

Insurance companies should not dictate if we need hysterectomies. Also, oncologists and Gyn's should let us make our own decisions. The Gyn's make their own recommendations for care and I hope they start making recommendations for hysterectomies after breast cancer.

I had no idea the types of uterine cancers that could attack me. Serous uterine cancer is viscious and extremely difficult to cure, almost impossible. I didn't believe it at first but as time went on I could see how quickly it moved.

In my situation tamoxifen is not an evil drug. But I could have been given options so that I could have lived a full life. My daughters are so angry they will lose me because I took a drug that could cause cancer.

I will be happy to help you in any way I can. I am so happy someone is researching this.

Thank you, Diane Smail

Please keep up your work. I know I have a different view. I am also a nurse practitioner.

california_artist's picture
Posts: 865
Joined: Jan 2009

What thoughts do any of you have on the current trend to offer removal of the breasts for those with Bra c 1 (not sure how to type that), and the refusal to offer or even consider a hysterectomy for those who have taken tamoxifen? There has been clear evidence of the connection of tamo to uterine cancer, and not the general version, but to UPSC specifically.

Would it not be the same reasoning. Can you have it if you pay for it yourself? Is it an insurance thing do you think? Could one lobby or file civil suits based perhaps on discrimination, to get the same sort of treatment based on the premise of how the genetic testing is allowing women to have preventative surgeries.

There is quite a bit of info on the discussion of tamox and uterine cancer. This site has a very long article, lots of info and additionally a great reference with full text and abstracts of many articles.

Just a bit of the article. Tamox has proven to be highly effective in further cancer developments in breast tissue. It's just the other problem that is-well-the problem.

Might there be therapeutic choices one could make to enhance the effectiveness and counteract the risks. Yerp, I do mean some sort of food thing.

Article: Is tamoxifen a genotoxic carcinogen in women?

Quote from this article: "...This review spans the clinical justification for tamoxifen as a chemopreventive agent, through to the very latest information on the mechanisms considered responsible for tamoxifen-induced tumours in rat liver and how these relate to women..."

From the Oxford Journal


Next Section
The anti-oestrogen tamoxifen, which is widely used in the treatment of breast cancer and is also approved for the prevention of this disease, causes an increased incidence of endometrial cancer in women. The ability of tamoxifen to induce endometrial tumours and the underlying carcinogenic mechanisms have been a subject of intense interest over the last ∼20 years. They are central to the assessment of risks versus benefits for the drug, especially in a chemopreventive context. This review outlines the clinical justification for using tamoxifen as a chemopreventive agent and describes the genotoxic mechanisms considered responsible for tamoxifen-induced tumours in rat liver and how these might relate to women. In rat hepatic tissue, tamoxifen is metabolically activated via α-hydroxylation and sulphate conjugation to give a reactive species that binds to DNA predominantly at the N2-position of guanine, producing pro-mutagenic lesions. Whether tamoxifen–DNA adducts contribute similarly to the development of cancers in women depends on whether they can be formed in human tissues and the type of specific molecular and cellular responses they induce, if present. This review discusses the current data relating to these issues and highlights areas where further research is needed.

The anti-oestrogen tamoxifen ((Z)-1,2-diphenyl-1-[4-[2-(dimethylamino)ethoxy]phenyl]-1-butene) was the first of a class of drugs, now referred to as selective oestrogen receptor modulators (SERMs), to be used clinically. Originally developed as an oral contraceptive, tamoxifen was actually found to induce ovulation in subfertile women and was marketed for this indication instead. In the early 1970s, following promising preliminary results in post-menopausal breast cancer patients (1), tamoxifen was reinvented as an anticancer drug and is now the most widely used adjuvant therapy in the treatment of breast cancer. Randomized clinical trials have demonstrated that adjuvant tamoxifen results in increased disease-free survival and a decrease in breast cancer recurrence rates saving thousands of lives each year (2). For oestrogen receptor (ER)-positive disease, 5 years adjuvant tamoxifen reduces the annual breast cancer death rate by 31% (3). Furthermore, in this setting, 5 years of tamoxifen lowers the risk of developing contralateral breast cancer by ∼47%, with shorter treatment durations associated with proportionately smaller reductions (4). Five years of therapy currently appears to be optimal, and remarkably, the benefit persists for at least a decade after ceasing treatment (3).


The pharmacological properties of tamoxifen are complex, being both species and tissue specific, and potentially dependent on the duration of use. Tamoxifen is generally classified as a partial oestrogen antagonist in humans, where it functions by blocking the action of oestrogen in the breast by binding to the ER and inducing conformational changes that prevent interaction of the receptor with coactivator proteins (5). In contrast, in post-menopausal women, tamoxifen exerts oestrogenic activity in the endometrium, vaginal epithelium, bone and on serum lipids, which manifests as protective effects against both cardiovascular disease (6,7) and osteoporosis in breast cancer patients (8).

Adverse effects include an increase in the occurrence of deep vein thrombosis or pulmonary embolism (9), whilst a stimulatory action on the endometrium due to tamoxifen-activated gene transcription may be a contributing factor to the elevated incidence of endometrial tumours in women treated with this drug (10,11). The ability of tamoxifen to induce endometrial tumours and the underlying carcinogenic mechanisms have been subjects of intense interest over the last ∼20 years and are central to the assessment of risks versus benefits for the drug, especially in a chemopreventive context. This review spans the clinical justification for tamoxifen as a chemopreventive agent, through to the very latest information on the mechanisms considered responsible for tamoxifen-induced tumours in rat liver and how these relate to women. Emphasis is also placed on the potential for DNA adduct formation in human tissues and the subsequent biological effects these might elicit, with discussion of the approaches currently available for assessing the significance of DNA damage.

california_artist's picture
Posts: 865
Joined: Jan 2009

As I was waiting for the thing to load I was just perusing it and this quote stood out-

This review spans the clinical justification for tamoxifen as a chemopreventive agent, through to the very latest information on the mechanisms considered responsible for tamoxifen-induced tumours in rat liver and how these relate to women.

clinical justification for tamoxifen as a chemopreventive agent----So, if they use surgery, chemo, radiation as preventative therapies and those are paid for by insurance companies, then with all of the supporting literature that tamo is a cause of uterine cancer and UPSC at that, why then can't they or won't they use hysterectomy as a preventative measure? Can you force a doctor or insurance company to use the latest methods to prevent disease from occurring?

I'm just saying. anyone a lawyer????

And Diane, thank you so much for sharing. You know how much I love you and wish you only the best in all this.


Kaleena's picture
Posts: 1781
Joined: Nov 2009


One cannot force doctors or insurance companies to use the latest methods. There are a lot of "small print" to allow "errors" or to deny or allow certain procedures. When a patient signs those documents that we sign, we sign that we know of the dangers, etc., of taking drugs or that the treatment we are receiving we approve and understand there could be circumstances beyond the control of physicians, etc. etc.

However, that is not to say that one could make a petition to allow such a procedure. You can appeal the insurance companies decision if you got a denial. Sometimes they will allow such a procedure if the case is presented to them.

With regard to a general allowance, it takes a lot of time and effort on many to do this. I further believe this is already started through the breast cancer because many woman who had family history of breast cancer wanted to have their breasts removed. You may want to look into how that is going to see if they got anywhere with that.


california_artist's picture
Posts: 865
Joined: Jan 2009

ON a personal sorta experience level, my daughter's doctor, because of my diagnosis with UPSC, suggested that my daughter get tested for the BRCA gene and further told her he would do the surgery to remove both her breasts if she came back positive.

WHAT'S UP WITH THAT??????????????????

Kaleena's picture
Posts: 1781
Joined: Nov 2009

Its only a matter of time before the voices of women will be heard and we will be able to get the surgeries needed to prevent these horrible diseases.

With regard to your daughter, WHAT???? Anyway, for your daughter's sack I hope everything is fine.

myakka 2011
Posts: 2
Joined: Dec 2011

I was diagnosed with stage 0 breast cancer in August 2010( age 61) and had a lumpectomy followed by 6 weeks of radiation( no chemo was needed). I then went on Tamoxifen at my Doctor's suggestion and have been on it for a year. Every mammogram since then has come back negative. However, this month I was discovered to have a pelvic tumor so a total hysterectomy was done and I have now been told I have stage 3 Ovarian cancer/ Uterine Cancer. I have never smoked and drink very , very little. The OBGY/ONCOLOGISt told me this is in now way related to the breast cancer. He does not think I've had this Cancer very long but it grew fast.
There is no history of this kind of Cancer in our family. To me, it is just too much of a coincidence that I got this type of cancer after being on Tamoxifen for one year. The doctors try to tell you that the benefits outweigh the dangers but if I knew than what I know now I would have never started this medicine. It's probably alright if you had had a hysterectomy before taking it but either way I'll never know and if I bring up my concerns to a doctor they don't really want to talk about it. If there is ever any evidence proving that Tamoxifen is more dangerous than they make it out to be I will be furious.

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