Low CYP2D6 = No Tamoxifen 4 me. Are there other options?

Jill_MN

I had a lumpectomy which showed DCIS, grade 2 (with comedo necrosis). I am ER+. Because I want to avoid radiation, my surgeon did re-excision to obtain clean margins all around of at least 2.5 mm (some were 8 mm). My plan was to start Tamoxifen as a preventative. However, I was tested for the enzyme that metabolizes Tamoxifen and my body shows very low activity of the CYP2D6 enzyme needed. I don't want to take a drug that is NOT likely to benefit me (and I'm concerned about side effects). I've talked to my oncologist several times and she doesn't have any other suggestions for me besides trying the Tamoxifen just in case it works.



I'm reaching out for guidance as I know many of you have searched for alternative and adjunct treatments. I'm 45, premenopausal, 5'5 and 132 lbs. I work FT, and have 3 kids ages 7, 11, 13, so I don't have much time to exercise regularly. Our family eats healthy but not usually organic due to the high cost. I've searched the alternative threads but haven't found anything that fits my scenario.



Are there other women in this situation? If so, what have you done? Has anyone negated their ovaries (chemically or surgically) in order to simulate menopause in order to use the aromatase inhibitors (Arimidex, Aromasin or Femara)? It seems extreme but there aren't many options out there. Perhaps I should do nothing and just be vigilant about mammograms and MRIs.



I should also mention I have 2 sisters who have had mastectomies...no one has tested positive for the BRAC1/2 genes.



Hugs and thanks in advance for your time.

LindaLS

Hi Jill, I was also diagnosed with DCIS grade 2 with necrosis in February 2007 when I was 42. I also had a lumpectomy. I am premenopausal and was also prescribed Tamoxifen due to being 97% ER/PR+. After 2 years of taking Tamoxifen due to side effects such as reocurring ovarian cysts and very heavy periods I asked my doctor to do the CYPD26 test to see if the tamoxifan was actually benefiting me as I did not want to take it if it was not. The test came back as low metabalizer of the drug. My doctor and I discussed it and decided that since I was having side effects that were troublesome and the test came back as extremely low metabolizer I dicontinued the tamoxifan. Makes sense right? But since then there has been an ongoing controversy if the test is truly an indicator of the drugs metabolization or if the drug could still be actually benefiting you regardless. They have done studies that indicates they really don't know what the results of the test really means. If you go to Dr Susan Love Research Foundation link http://www.dslrf.org/breastcancer/content.asp?CATID=19&L2=3&L3=7&L4=0&PID=&sid=132&cid=1146 you will be able to read the info for yourself. Just want to make sure you are aware that the test has not been 100% validated and questions about it remain. I wonder at this point if I should have just continued to take the tamoxifan for the 3 years after I discontinued it. It crosses my mind but it is what it is. I hope this helps you look into it further and talk to your doctor about it more extensively. I would be interested to know what your doctor's take on it is. Good luck with everything. sincerely, Linda      

coraleliz

Look up the drug toremifen(Fareston). It was developed for nonmetabolizers of Tamoxifen. It's much more expensive & I don't know if I ever seen anyone on these boards taking it for DCIS. My MO mentioned switching me to this drug because of all my side effects. I always found it interesting that the severity of side effects doesn't corelate with how well we metabolize Tamox. It can be used both pre & post meno altho most of the info is for post meno. I never had the CYP2D6 test.