does hormone status change with age?

This brings up the topic again of why do some doctors test for Her2Neu status with DCIS and some (like mine) do not.  I understand the theory but not the reasoning, I guess. 

I have asked before, if DCIS is all contained and wrapped up all pretty with a bow, then why can't we just resume our hormone therapy since there isn't a chance of being invasive-- especially with a BMX as the chosen treatment option??  I, for one, would like to avoid the awful SE's of forced menopause that not using hormone therapy gives me.    Beesie???

Here's why it's recommended that someone diagnosed with DCIS not go back onto hormone replacement therapy:

Anyone who's been diagnosed with BC one time is assumed to have a higher risk of developing BC again.  This is true whether the cancer was caught while it was still DCIS or whether the cancer was invasive. This risk is additional to and different from recurrence risk (the risk that the original cancer might not have been fully removed and might recur). This risk refers to the development of a new primary breast cancer, unrelated to the original cancer.  The reasoning is simply that if your body developed cancerous cells in your breast one time, whatever factors caused or allowed those cancer cells to develop may still be at play and therefore your body might develop cancerous cells in your breast again.  My oncologist told me that my risk was about double that of the average woman my age but I've seen articles that suggest that the risk might be higher than that.  

It's also known that hormone replacement therapy increases breast cancer risk. Here's what BC.org say about that:  Using HRT (Hormone Replacement Therapy) . 

So it's all a question of risk level. After being diagnosed, we all are higher risk than average. If you add HRT on top of that, you increase your risk even more.  Those who've had lumpectomies or single mastectomies (i.e. those who still have one or two breasts) obviously have a higher risk than those who've had BMX.  But even with after a BMX for DCIS, you still have approx. a 1% - 2% chance of local recurrence (a recurrence of the original cancer; the 1% - 2% risk figure assumes good margins) and approx. a 1% - 2% chance of the development of a new cancer.  A recurrence or a new cancer could be DCIS or it could be invasive - there's no guarantee that it will just be DCIS again. Using HRT possibly fuels the development of the few cancer cells that might remain after the mastectomy or that might develop in the small amount of breast tissue that remains after a BMX. 

This risk - the risk of a local recurrence or a new primary BC that might develop to be invasive and that therefore could have the potential to spread - is obviously different than the risk that someone who had invasive cancer faces.  For someone who had invasive cancer, the risk from HRT is more immediate.  So ultimately for those who had DCIS, it is a choice.  If not taking HRT is having a significant impact on your quality of life, find out from your oncologist what your recurrence risk and new primary risk level is and how much it might be increased if you take HRT.  Then decide if taking HRT is worth that extra risk. 

As for HER2 testing for DCIS, at this point the information on HER2 status does not provide much value, except for the very few women who might be eligible to participate in one of the small clinical trials underway for HER2+ DCIS.  I believe that the reason some labs do the HER2 testing on DCIS is just so that the information is on the record for the future, in case we learn more and it does one day become relevant.  

Here's what we know, and don't know, now about HER2+ DCIS:  

• We know that DCIS is much likely to be HER2+ than IDC.  Only about 20% of IDC is HER2+ but approx. 40% of DCIS is HER2+ (I've seen some studies with numbers as high as 60%).  
• We don't know why more DCIS is HER2+.  When HER2+ DCIS evolves to become IDC, does the HER2 status change?  Or does a lower percentage of HER2+ DCIS evolve to become IDC? 
• We don't know whether HER2+ DCIS is more aggressive.  It's well established that HER2+ IDC is more aggressive but most studies show no difference between HER2+ and HER2- DCIS.  A recent retrospective of studies on HER2+ DCIS showed that 11 out of 15 studies reported no difference in recurrence rates between those who had HER2+ vs. HER2- DCIS. A number of small studies have shown that HER2+ is more aggressive but there have also been a couple of studies that have shown that HER2+ DCIS is less aggressive. So the jury is still out on this one.
• We know that at this time there are no differences in treatment for those who have DCIS that is HER2+ vs. those who have DCIS that is HER2-. Herceptin, which is the drug given to women who have HER2+ IDC, is not approved for DCIS.  There are a couple of clinical trials underway on potential treatments for HER2+ DCIS; I believe that only one is still recruiting. 

All in all, that's why HER2 testing often isn't done on DCIS.  There's nothing that can be done, at this time, with the result.  

Bumping this thread for the lady asking about her2 status and dcis