question about her2serum test

[Lauriesh]

I was wondering, after reading kim's thread about her her2serum test results, how many stage 4 women are now having this test.

I have been stage 4 for almost a year and have not had it yet.

I read some old threads from 2009, and saw back then that a lot of oncs weren't using it. Has it become more widely used in the last couple of years?


Also, I read some of the studies that talked about how a low her2serum result can predict longer survival (I hope that I read that correctly)
Do you think that having a low tumor marker result is predictive of prognosis/survival? My tumor marker (ca 27) ranged from 9 to 11 from when I was diagnosed stage 2 in 2005 until March, 2010. It was at 50 when I was diagnosed with liver mets in July, 2010. I am now NED, and my number is back at 9. I know that if it would start to rise, it is probably an indicator that I should have scans, but does a low number mean anything in terms of prognosis/survival?
Thanks,
Laurie

[Jackie07]

Laurie,

Looks like the members on this Board have been way ahead of the game:

Cancer Treat Rev. 2011 May 4. [Epub ahead of print]
HER2 shedding and serum HER2 extracellular domain: Biology and clinical utility in breast cancer.

Tsé C, Gauchez AS, Jacot W, Lamy PJ.
Source

Laboratoire de Biochimie Métabolique, Groupe Hospitalier Pitié-Salpêtrière, Assistance Publique-Hôpitaux de Paris, Paris, France.

Abstract

The transmembrane protein HER2 is over-expressed in approximately 15% of invasive breast cancers as a result of HER2 gene amplification. HER2 proteolytic cleavage (HER2 shedding) generates soluble truncated HER2 molecules that include only the extracellular domain and the concentration of which can be measured in the serum fraction of blood. HER2 shedding also generates a constitutively active truncated intracellular receptor of 95kDa (p95(HER2)).

Another soluble truncated HER2 protein (Herstatin), which can also be found in serum, is the product of an alternatively spliced HER2 transcript. Recent preclinical findings may provide crucial insights into the biological and clinical relevance of increased sHER2 concentrations for the outcome of HER2-positive breast cancer and sensitivity to trastuzumab and lapatinib treatment.

We present here the most recent findings about the role and biology of sHER2 based on data obtained using a standardized test, which has been cleared by FDA in 2000, for measuring sHER2. This test includes quality control assessments and has been already widely used to evaluate the clinical utility of sHER2 as a biomarker in breast cancer. We will describe in detail data concerning the assessment of sHER2 as a surrogate maker to optimize the evaluation of the HER2 status of a primary tumor and as a prognosis and predictive marker of response to therapies, both in early and metastatic breast cancer.

[Lauriesh]

Thanks Jackie for the study. I think I will have to bring it up with my onc next time, and see if I can convince him to run it.



Laurie

[Rich66]

Don't be surprised if the onc balks. It's relatively new and when you look at the various research, not exactly definitive in utility. It seems to be like typical tumor markers, a great indicator for some, less so for others. I think there is someone here on the board who is maintaining on Herceptin.. going back on it when serum her2 rises. I sure wish it was more black and white..but then it couldn't be cancer related

[tricia keegan]

Is this test only used for stage iv???

[Jackie07]

Laurie is asking those who are using the Her2 serum test to share their experience.

I don't have the experience, so I just keep on doing research on this subject. The abstract below 'validates' the prognostic value of CTC (Circulating Tumor Cells) independently from Her2 serum value.

Ann Oncol. 2011 Jun 3. [Epub ahead of print]
High independent prognostic and predictive value of circulating tumor cells compared with serum tumor markers in a large prospective trial in first-line chemotherapy for metastatic breast cancer patients.

Pierga JY, Hajage D, Bachelot T, Delaloge S, Brain E, Campone M, Diéras V, Rolland E, Mignot L, Mathiot C, Bidard FC.
Source

Department of Medical Oncology, Institut Curie, Paris.

Abstract

BACKGROUND:

Circulating tumor cells (CTCs) are a prognostic marker in metastatic breast cancer, but comparisons with serum tumor markers (CA 15-3, carcinoembryonic antigen and lactate dehydrogenase) variations are needed.
PATIENTS AND METHODS:

CTCs were counted with CellSearch® at baseline, before cycle 2 (C2) and cycle 3 or 4 (C3/4) in 267 metastatic breast cancer patients on first-line chemotherapy with/without targeted therapy.
RESULTS:

Baseline CTC detection rate was 65% with ≥1 CTC/7.5 ml threshold and 44% with ≥5 CTC/7.5 ml and was independent of subtypes (luminal, triple negative, human epithelial growth factor receptor 2 (HER2)+). CTCs were associated with tumor markers, bone/liver involvement, tumor burden and performance status. CTC detection ≥1 CTC/7.5 ml was a strong prognostic factor for progression-free survival (PFS), P < 0.0001. Threshold of CTC ≥5 was statistically significant for PFS and overall survival (OS), P = 0.03 on multivariate analysis. Among patients with ≥5 CTC/7.5 ml at baseline, 50% had <5 CTC/7.5 ml at C2. Changes were correlated with both PFS and OS (P < 0.0001). All patients receiving anti-HER2 therapy had <5 CTC/7.5 ml after three cycles of treatment.
CONCLUSION:

This is the largest prospective series validating the prognostic value of CTC independently from serum tumor marker. Elevated CTCs before C2 are an early predictive marker of poor PFS and OS, which could be used to monitor treatment benefit. CTC decrease under treatment seems stronger with targeted therapy.

[Lauriesh]

Hi Rich, does your mom have the test done? If she does has it been useful?

Any other stage 4's who are using it? Has it been helpful? Any problems getting insurance to pay for it?


thanks,

Laurie

[Rich66]

Mom had it done a couple times. It was alittle weird from eth beginning since the lab used seemed to have a different cutoff point (lower) than typical. It was slightly elevated according to that cutoff. And it did go down after first Herceptin. And she did hold on just Herceptin for a bit. So I guess teh slight elevation was used as justification for trying Herceptin despite a borderline but considered negative FISH result. Considering Herceptin held her for some time, seems to suggest some level of Her2 activity. Papers being flung back and forth since have put into question the utilityof serum her2. But again..I wish I could remember who was using serum Her2 as a barometer for when to get back on Herceptin. I think I read somewhere along the line that there may be different ways to measure serum her2 so maybe the idea has validity but the test is imperfect. I guess it was of value to mom in that it allowed an experiment with Herceptin that probably couldn't have been justified otherwise. I think of it as a tool in the toolbox that may or not be helpful. Probably one of those things that shows value, if it has any for a given patient, over time.

[Jackie07]

Here's a thread where several members have shared their experience in Her2serum test not long ago.

[Jackie07]

Here's the link to another thread on the topic:

http://her2support.org/vbulletin/sho...ight=her2serum