I’ve been pathologically checking for the final pathology (haha see what I did there — oh *sigh* I’m so lame I can’t stand myself).
Anyway, as I expected, the tumor they biopsied is ER/PR+ (as was my DCIS in 2013), which is good news because ER or PR positive receptors tend to grow slower than negative ones. What this also means is that doctors will likely use hormone therapy to stop estrogen and/or progesterone from activating the cancer cells. Still, I don’t understand this part at all: I’ve managed to grow estrogen/progesterone activated cells after having my uterus and ovaries removed six years ago – how? My research says that in postmenopausal women, androgens can be turned into small amounts of estrogen. I have a different theory – I continue to think these are the same DCIS cells from back then, before I had the hysterectomy/oophorectomy; they hung out in there mutating until they formed this lump I have now, and they’re ER/PR positive because that’s what activated them in the first place. If that’s the case, then what that also means is if someone had recommended I take Tamoxifen for several years after my mastectomy, I might not be in this situation.
Pathology also tested for HER2, and this came back “equivocal” or inconclusive. This is not great news. From what I understand, HER2 status (positive or negative) is pretty much the most important piece of the treatment puzzle. I emailed Dr. McAuliffe to ask what they’ll do about that. My understanding is that they can test for HER2 in at least two ways – an inexpensive way that shows results quickly, and an expensive way that takes longer. Since there is no description of methods in the pathology report, my hope is that they only did the first test, and they are currently working on the second test.
Because there are drugs made specifically to target HER2, it seems like it’s really important to know HER2 status:
In the era of precision medicine, human epidermal growth factor receptor 2 (HER2) is the most important predictive and prognostic biomarker in breast cancer (Gunn).
Yet, it is hard to know that status conclusively:
Inaccurate HER2 test results may cause women diagnosed with breast cancer to not get the best care possible. If all or part of a breast cancer is HER2-positive but test results classify it as HER2-negative, doctors aren’t likely to recommend anti-HER2 treatment — even though the woman could potentially benefit from [it]. If a breast cancer is HER2-negative but test results classify it as HER2-positive, doctors may recommend anti-HER2 treatment — even though the woman is unlikely to get any benefits and is exposed to the medicines’ risks. (breastcancer.org)
So, I’m glad I am having my pathology looked at by the Penn pathologists. I’m hoping that between two sets of pathologists, some clarity will be gained and I will get the correct treatment and prognosis.
Lastly, pathology showed that my rate of cell growth (Ki-67) is really high (mine is 40%; above 20% is considered high). This means that when they did the staining procedure, they could see 40% of the cancerous cells dividing to form new cancerous cells.
To sum up:
ER/PR positive = good
Ki-67 high = bad
HER2 equivocal = ??
Looks like we have a tie breaker, folks. Stay tuned.
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