Recurrence while on Tamoxifen

As someone who hasn't made the yes or no to tamoxifen decision yet, Why is she opposed to tamoxifen

Check the posting earlier today about estrogen...it had a few interesting points about tamoxifen.  I'm not eligible for that therapy so haven't been paying much attention to that dimension.

all the literature states that tamoxifen generally works in about 50% of the people who take it to prevent bc (from either occuring initially or reoccuring), so that obviously means that it doesn't appear to work in the other 50%.  However, I don't think the bc is any  "nastier" if it reoccurs, at least I haven't read anything that states that.  I'm just hoping I'm in that 50% that gets a benefit from taking it!  Praying for good results for you.

I remember reading an article very recently that was a little alarming, along the lines of what you're talking about, and I actually found it!

I guess you'd have to know if your breast cancer was resisistant to tamoxifen, and I have no idea how you find that out ahead of time.  Somehow though the study authors had to find that out....not sure I understand it all.  In any case, here it is:

 Proc Natl Acad Sci U S A. 2007 Dec 27 [Epub ahead of print]

Tamoxifen-stimulated growth of breast cancer due to p21 loss.
Abukhdeir AM, Vitolo MI, Argani P, De Marzo AM, Karakas B, Konishi H, Gustin JP, Lauring J, Garay JP, Pendleton C, Konishi Y, Blair BG, Brenner K, Garrett-Mayer E, Carraway H, Bachman KE, Park BH.

The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD 21231;

Tamoxifen is widely used for the treatment of hormonally responsive breast cancers. However, some resistant breast cancers develop a growth proliferative response to this drug, as evidenced by tumor regression upon its withdrawal.

To elucidate the molecular mediators of this paradox, tissue samples from a patient with tamoxifen-stimulated breast cancer were analyzed. These studies revealed that loss of the cyclin-dependent kinase inhibitor p21 was associated with a tamoxifen growth-inducing phenotype.

Immortalized human breast epithelial cells with somatic deletion of the p21 gene were then generated and displayed a growth proliferative response to tamoxifen, whereas p21 wild-type cells demonstrated growth inhibition upon tamoxifen exposure.

Mutational and biochemical analyses revealed that loss of p21's cyclin-dependent kinase inhibitory property results in hyperphosphorylation of estrogen receptor-alpha, with subsequent increased gene expression of estrogen receptor-regulated genes.

These data reveal a previously uncharacterized molecular mechanism of tamoxifen resistance and have potential clinical implications for the management of tamoxifen-resistant breast cancers.

PMID: 18162533 [PubMed - as supplied by publisher]

I didn't have a recurrence on tamoxifen but was diagnosed stage 4 one year out from stopping. I had taken it for 2 lots of 5 years. Even though my tumours are highly er/pr positive my Onc is highly suspicious that I have developed a resistance to tamoxifen and is reluctant to try me on it again. Well at least not until my mets are more under control.

Oldoaktree, it is good to learn the info you delivered in your message, have you figured out the "nasty recurrence" while on Tamox?

Hi. Im on tamoxifen and i found a lump in my breast been there for 2 months. Could it be cancer

Look into (aka Google) the Breast Cancer Index (BCI) test by Biotheranostics. BCI is to tamoxifen and AIs what the Oncotype DX test is to chemo.

Also read the stage IV forum here.

That is what I did and both helped me immensely.