HER2 Support Group Forums - View Single Post - here we go again: How inexact ER status testing is!!!

Lani · 07-10-2007, 09:31 AM

gotta go (long post for TSUND) so will make this fast

her2+ virtually always metastasizes at her2+ (can cite papers if needed)
Usually if discordant, method of her2 testing reexamined

At conferences I attend, including SABCS, the oncologists are always bemoaning the fact that they don't get a chance to get a biopsy of mets
(I raised my hand and asked why bone marrow biopsies aren't more prevalent to assess residual disease and was either ignored or scoffed at)

Lung mets can be dangerous to biopsy and sometimes very inaccessible.

ER negatives usually don't "turn positive" but giving lapatinib can cause a 40-70% increase in ERs I believe I read--so if you were .8% positive (considered negative) I suppose you could become positive.It isn't that the ER- tumors "turn" positive, it is that they were misdiagnosed for technical reasons initially or perhaps that a treatment allowed those cells which had ERs to be selected out (like weeds in a garden, if you use a weed killer that doesn't get dandelions, dandelions will no longer have to compete with the other weeds and will become predominant.

Walter Carney has published on the use of serum her2 to detect those tumors which start out her2- but become her2+ when they become resistant to antihormonals and/or recur.

Most answers in cancer are not "yes" and "no". It is far to complicated a field and too poorly understood. Let's hope it doesn't stay that way long!

07-10-2007, 09:31 AM	#13
Lani Senior Member Join Date: Mar 2006 Posts: 4,780	Flori gotta go (long post for TSUND) so will make this fast her2+ virtually always metastasizes at her2+ (can cite papers if needed) Usually if discordant, method of her2 testing reexamined At conferences I attend, including SABCS, the oncologists are always bemoaning the fact that they don't get a chance to get a biopsy of mets (I raised my hand and asked why bone marrow biopsies aren't more prevalent to assess residual disease and was either ignored or scoffed at) Lung mets can be dangerous to biopsy and sometimes very inaccessible. ER negatives usually don't "turn positive" but giving lapatinib can cause a 40-70% increase in ERs I believe I read--so if you were .8% positive (considered negative) I suppose you could become positive.It isn't that the ER- tumors "turn" positive, it is that they were misdiagnosed for technical reasons initially or perhaps that a treatment allowed those cells which had ERs to be selected out (like weeds in a garden, if you use a weed killer that doesn't get dandelions, dandelions will no longer have to compete with the other weeds and will become predominant. Walter Carney has published on the use of serum her2 to detect those tumors which start out her2- but become her2+ when they become resistant to antihormonals and/or recur. Most answers in cancer are not "yes" and "no". It is far to complicated a field and too poorly understood. Let's hope it doesn't stay that way long!