HER2 Support Group Forums - View Single Post - Can HER+ status change from initial to final path report?

al from Canada · 12-09-2005, 09:51 PM

Dear Ladies,
I listened to Dr. Sleaman address this today and he stated that it is not unusual to get IHC 3+ and FISH (-), as they really measure different things, where one uses staining and the other counts duplicate copies something like a xerox machine. There is also a well accepted level of inaccuracy (around 15%) of false positives and negatives. He also indicated that NONE of the IHC3+, FISH (-) patients resonded to herceptin so clearly, FISH is the only way to go. There is also minor changes in FISH values over time however I think the trend during metastatic disease is up-regulation of HER2.

From another post earlier today:
Cancer has proven to be a VERY sneaky opponent with numerous pathways to plug into when assualted. IE, cross-talk between ER and HER2 may upgrulate HER2 if the cancer is being killed by ER therapy. Likewise, if you are HER2+ and ER+ and on herceptin, you may find that ER become up-regulated. The delimma that I think many HER2 - MBC patients face is is what is the HER2 status of the mets and how do we test for it, while the least invasive method is fine-needle asperation.

The readers digest version.....if you develop MBC, don't make the assumption that HER2 status is the same as the primary tumor,,,that one could cost you dearly.

Regards,
Al

12-09-2005, 09:51 PM	#6
al from Canada Senior Member Join Date: Jul 2005 Location: Ontario, Canada Posts: 722	from SABCS Dear Ladies, I listened to Dr. Sleaman address this today and he stated that it is not unusual to get IHC 3+ and FISH (-), as they really measure different things, where one uses staining and the other counts duplicate copies something like a xerox machine. There is also a well accepted level of inaccuracy (around 15%) of false positives and negatives. He also indicated that NONE of the IHC3+, FISH (-) patients resonded to herceptin so clearly, FISH is the only way to go. There is also minor changes in FISH values over time however I think the trend during metastatic disease is up-regulation of HER2. From another post earlier today: Cancer has proven to be a VERY sneaky opponent with numerous pathways to plug into when assualted. IE, cross-talk between ER and HER2 may upgrulate HER2 if the cancer is being killed by ER therapy. Likewise, if you are HER2+ and ER+ and on herceptin, you may find that ER become up-regulated. The delimma that I think many HER2 - MBC patients face is is what is the HER2 status of the mets and how do we test for it, while the least invasive method is fine-needle asperation. The readers digest version.....if you develop MBC, don't make the assumption that HER2 status is the same as the primary tumor,,,that one could cost you dearly. Regards, Al __________________ Primary care-giver to and advocate for Linda, who passed away April 27, 2006.