estrogen receptor score

Diagnosed Feb. 07, invasive BC, stage 2, grade 3, neg. lymph node. Estrogen receptor score was 10, which I am told is the first value at which it is considered estrogen receptive.  What is the meaning of a low score for tamoxifen efficacy and prognosis?  Was peri menopausal at diagnosis, but periods ceased during chemo.  Understand this impacts prognosis, but am uncertain where I fall (pre menopausal recurrence peaks at 8 - 10 months and 28 - 30 months,  post treatment, menopausal  18 - 20 months).  Many thanks.

[PaulMD]

Hi there.

The density of the estrogen receptors are the ones being reported when being tested.  This eliminates the traditional reporting of just estrogen receptor positive or negative.  A value of 10 means that you have enough estrogen receptor density that can make the tumor responsive to hormonal therapy (tamoxifen for premenopausal or aromatase inhibitors for post menopausal), and decrease the chance of recurrence.  If you have ceased menses during chemo, then it may be an option for you to ascertain your menopausal status through testing for estradiol, FSH, and LH levels.  If these levels are postmenopausal in values (they have cut-off levels), then you may derive more benefit from aromatase inhibitors (letrozole, anastrozole, or exemestane) compared with tamoxifen.  I suggest you discuss all of these options with your oncologist.  Regards and God bless.