Tamoxifen- Aug 2009 report

maryed34 · August 2009

I am taking Tamoxifen for LCIS and started treatment in May. I read an article that Tamoxifen now increases the risk of developing an Estrogen Receptor Negative form of breast cancer which happens to be rare- but more aggressive and not easy to treat. Does it still make sense to take Tamoxifen for prevention of ER positive Breast cancer- when the risk for ER negative breast cancer increases? What does everyone think?

Krisc · August 2009

Hi Mary, I am taking Evista for my LCIS diagnosed in March 2009. But I am post menopause. My oncologist said that because I am not having periods any longer, that Evista is a better choice for me. He also said Evista has fewer side effects; although it appears to me to have many. I was concerned that I was not taking Tamoxifin first, which seems to be the standard for LCIS. I have not read the article you referred to. I do know it can be quite confusing and scary when you read everything posted about drugs. We wonder if they help more or hurt. I think Tamoxifin has proven itself to be very valuable. Call your oncologist or gyn and ask about the article. I did when I read that a little know side effect of Evista was ovarian cancer. My docs did not seem to think it was an issue with Evista. Remember that Tamox has been around for at least 25 years so it is pretty much tried and true.

Krisc · August 2009

WebMD has an article posted entitled, "Tamoxifin-risk of rare second cancer". It looks as if the risk is small. The article does state there are benefits and risks to all drugs, which we all know is true. Just talk with your oncologist for her thoughts. She may have the specifics and percentages that may make you feel better.

maryed34 · August 2009

Thanks for your advice. I read another article posted on the home page of this web site (new research area) and still have conflicted feelings. I'm 43- I don't think I want to take something that will lower my risk of developing bc but may cause me to develop a more aggressive form of bc. I faxed the article to my onc and will probably hear back from her next week. Thanks again!

Anonymous · August 2009

Mary--- I've never heard of tamoxifen causing any kind of bc, but it does carry a small (less than 1%) but serious risk of endometrial cancer. (it's good to be monitored yearly with a transvaginal ultrasound while on tamox to monitor the uterine lining and the ovaries). Last fall I finished my 5 years of tamox for prevention (I have LCIS and family history of ILC) and now I take Evista for further preventative measures and continue with high risk surveillance of alternating MRIs and mammos. I tolerated tamox well with only mild SEs, mainly hot flashes. My mom did very well with tamox also; now is a bc survivor of over 22 years without a recurrence.

Anne

nash · August 2009

Here's a link to the article on WebMD about the study the thread is referring to:

http://www.webmd.com/breast-cancer/news/20090825/tamoxifen-rare-second-breast-cancer-risk?src=RSS_PUBLIC

It is important to note that the increased risk of TN cancer in the study was only seen in women who took Tamoxifen for more than five years.

leaf · August 2009

This may be the article that maryed was concerned about. http://health.usnews.com/articles/health/healthday/2009/08/25/tamoxifen-may-up-risk-of-second-more-aggressive.html

I can't find the abstract of this article in Pubmed, it is probably too new. Since the usnews.com is not a scientific journal, I don't know if this article was mis-represented.

In the trials, it was shown that tamoxifen reduced the number of ER positive invasive breast cancers, but did not change the incidence of ER negative invasive cancers.

Since ER negative cancers include the triple negative invasive cancers, which are known to be more aggressive, would tamoxifen predispose a tamoxifen user to more triple negative cancer?

In this article, it says, interestingly, that 5 years of tamoxifen seems to have a preventative effect that lasts at least 10 years. http://jco.ascopubs.org/cgi/content/full/27/19/3235

In the STAR trial, apparently, comparing the tamoxifen and raloxifen users "When we assessedthe pathological characteristics of the tumors in these patients,there were no differences between the treatment groups in regardto distributions by tumor size, nodal status, or estrogen receptorlevel (Table 2)." http://jama.ama-assn.org/cgi/content/full/295/23/2727

In this paper in RATS, tamoxifen seemed to bind to certain sites on DNA, and cause pro-mutagenic lesions. http://mutage.oxfordjournals.org/cgi/content/abstract/24/5/391 Whether or not this happens in humans is unknown.

This 2001 paper talks about some of the pitfalls in assessing tamoxifen for ER negative breast cancer. http://jco.ascopubs.org/cgi/content/full/19/suppl_1/93s

It does sound like, however, the tamoxifen users who did get ER negative breast cancers had their ER negative cancers detected earlier than the non-tamoxifen users. http://www.breastcancer.org/treatment/hormonal/new_research/20081007.jsp

I

maryed34 · August 2009

Thanks leaf and everyone. I just don't want to be unnecessarily hurting myself by taking Tamoxifen- if there is a possible link of developing a worse form of bc. I continue to take my 20 mg and I will let everyone know what my onc says next week.

kristifromsandiego · August 2009

Hello everyone. I started Tamoxifen in May after chemo and radiation. I went to my oncologist yesterday and he had already heard all the reports regardingTamoxofin. He stated that he wanted me to stay on it till I was "in menopause", this is classified one year without periods. Chemo stopped all periods for me. I have not had one since October after my first chemo, so come November my oncologist is switching me to something else. I don't yet know which drug will be the drug of choice. good luck Kristi

maryed34 · August 2009

Just had a call from my onc. She said to continue with the Tamoxifen and we'll revisit everything after all of my tests in October. Thanks for all of your support.

Tamoxifen- Aug 2009 report

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