How Significant is % Estrogen Receptor Positive

kayb,

thank you, yes that's enormously helpful. I am thinking  then that I am Luminal A type. I never knew this.

Devine, it is all very confusing isn' t it? If it reassures you chemo was do-able for me. What is scaring so?  

Hello all, I wanted to respond to the question in this thread.  I am highly ER+ and just barely PR- (but negative just the same).  My onco explained to me that every breast cancer is individual.  There are lots of combinations of factors.  In my case I have a moderate K167 of 17% and Grade 1 tumor.  So I know that ER+/PR- tumors are not always fast growing tumors.

What was explained to me is that the hormone receptors put the cancer on a spectrum with highly positive ER/PR tumors most favorable, ER/PR  positive tumors next,  and Highly ER+/PR- next....etc.  My onc believes that the % of hormone positivity matters....but she wouldn't fail to prescribe hormone blockers even if there was slight positivity.    I think that the data about who benefits from hormone blockers and by how much is still unknown.  There is some research that states that PR- interferes with Tamoxifen in ER+ patients, but there have been no changes in treatment based on this research yet.  

The other reason that I believe that % of positivity matters is that part of the calculation of the Oncotype DX recurrence score includes the % of both ER and PR positivity.  While the oncotype DX test tries to answer the question about whether you would benefit from chemo....it assumes that you will be taking a hormone blocker for 5 years regardless of your positivity.  It makes sense to me that lower % of positivity would contribute mathematically to a higher recurrence score for both ER and PR.

MsP

hi Kay B thanks for that but I'm still uncertain as my tumour was also 100% progesterone positive. Still can't understand how it's grade 3

My tumor was Grade 2, 80% ER+ and PR- on pathology. On oncotype it was ER+ and PR+ (low but positive I guess). My oncotype score came back at 12. I was put on tamoxifen for  2 years even though post menopausal and having ILC,  before future switch to AI for 3 years due to me currently having thin hair and to reduce possibility of bone loss. I guess only time will tell...

devine

look at your pathology rept in the histology section. It shd say something about a Nottingham Scale and show 3 values...they look at the differentiation of cells, nuclear pleomorohism, and mitotic rate. Each is assigned a value from 1 -3. Then the total score is added up and a grade is assigned based on that total number. In my case my tumor had intermediate scores on the first two and a very low mitotic rate which was later supported by the Ki67 proliferation study. This scoring put me at the top end of grade 1 with a score if 5. My Er,Pr was highly positive at 99%. Hope this info is helpful.

zha-an

thanks for that my histology shows Score 3,2,3 which gave me 8 so grade 3. Just still confused as to how it can be with such high hormone receptor status. We have limited info here in uk and oncotype DX is not available to us. Had my first chemo on Tues and was an inpatient for two days following due to extreme nausea and vomiting.