value of serum her2 ecd test from St. Gallen abstracts

[Lani]

0055 Analysis of HER-2/neu extracellular domain in serum from
breast cancer patients: Correlation with clinicopathologic
parameters and prognostic significance
D. Vrbanec1 , G. Hor vatic-Herceg2 , M. Sirotkovic-Skerlev3 , S. Kralik4 ,
S. Jelisavec-Cosic5 , Z. Kovac5 , A. Kulic5 . 1 Depar tment of Medical
Oncology, Division of Oncology, 2 Clinical Depar tment of Nuclear Medicine,
University Hospital Center Zagreb, 3 Depar tment of Pathophysiology,
University Hospital Center Zagreb and Zagreb University Medical School,
4
Clinical Institute of Laborator y Diagnosis, University Hospital Center
Zagreb, 5 Depar tment of Pathophysiology, University Hospital Center
Zagreb and Zagreb University Medical School, Zagreb, Croatia
Goals: The aim of this study was to investigate the presence of HER-2/neu
extracellular domain (ECD) in serum from breast cancer patients and to
correlate the results with various clinicopathologic parameters: patient’s
age, size and histological grade of the tumor, status of axillar y lymph
nodes, expression of estrogen and progesterone receptors and Cathepsin
D levels in tumor tissue. Prognostic value of HER-2/neu ECD in serum
was also analyzed.
Methods: The serum from seventy eight patients with invasive
breast cancer and twenty individuals without malignancy was tested for
HER-2/neu ECD using ELISA method.
Results: Thir ty eight (48%) of 78 patients with breast carcinoma and
4 (20%) of 20 healthy controls had increased HER-2/neu ECD concen-
trations (cutoff 15 g/L). The concentrations of HER-2/neu ECD in serum
ranged from 5.35 to 93.96 g/L in serum from breast cancer patients and
between 5.35 and 16.86 g/L in serum from healthy individuals. Circulating
HER-2/neu ECD was significantly associated with the histological grade
of tumors and the status of axillar y lymph nodes. Negative correlation
was obser ved between HER-2/neu ECD in serum and estrogen receptor
positivity while no association was found with progesterone receptor status.
No correlation was found between circulating HER-2/neu ECD and the
age of the patients, the size of the tumor and the levels of Cathepsin
D. Kaplan–Meier analysis showed that patients with elevated HER-2/neu
ECD in serum had poorer prognosis (5-year sur vival) than the patients
with lower HER-2/neu ECD concentrations.
Conclusion: These results suppor t the value of circulating HER-2/neu
ECD as a marker of more aggressive phenotype and as a prognostic factor
in patients with breast cancer.

[StephN]

Thanks so much for that bit of news, Lani. I will be having my third such serum test drawn on Monday, and will mention this to my med onc (who seems to believe it has value before the study).

Hope this study can budge some of the oncs who have pooh-poohed this test, especially for stage IV patients with hormone negative status (such as myself).

[Joe]

Christine has been a firm believer in the test for several years now.

She just received her latest test results today:
6.7 mg /mL

Its been a great week for us.

Regards
Joe

[Mary Jo]

Is this a test to help determine if you've had a recurrence?

Thank you,

Mary Jo

[schoolteacher]

I will get my ELISA test next week. It will be interesting to see what my level is now since I have been off chemo for almost four months and have taken the Peptide vaccine twice.

Amelia

[Debbie L.]

Thanks, again, Lani. You are so good at keeping us up to date.

Okay, I do hope that this test eventually proves to be of benefit, but I do not see anything in this study that talks about what that benefit might be.

They tested people with and without breast cancer. People with breast cancer had higher levels, and the more aggressive the details of the breast cancer, the higher the number, apparently.

This appears to be reporting on the use of the test with primary breast cancer - I see no mention of using it to monitor for recurrence.

They report that the test is of prognostic value - able to predict which cancers will do worse. In a vague sort of way. I'm not sure I understand the value of that. If there's a HER2+ ERPR- grade 3 cancer, we already KNOW that it's expected to do worse.

This study didn't look at:
1. Reliability of this test to detect recurrence.
2. Ability of this test to prolong survival when detecting recurrence.
3. Ability of this test to indicate what treatment might be most effective (predictive value).
4. Ability of this test to monitor treatment response (indicate response to treatment early-on, before scans or other markers show response, so treatment that's not working doesn't have to be endured any longer than necessary and the next step can be taken).

Any of those things would be helpful (although the first one without the 2nd would be of questionable benefit). But I don't see any of those things in this study.

Other interpretations/explanations welcome.

Debbie Laxague

[StephN]

Good questions, Debbie. But what Lani posted is just the abstract, and the full report may answer a few of those questions you raised.

The way Christine and I are using this test is from a standpoint of having been long term on Herceptin. In establishing a "normal" HER2 serum level while on Herceptin, and having the courage to Stop the Herceptin, this is one way to monitor how we are doing while off Herceptin.

Neither Christine nor I have this test as our only marker for what may be happening in our bodies. We both have other bloodwork as well as periodic scans. Between all of those surveillance devices we hope to be tipped off early if our cancer again becomes active.

Other people may want to use this test while on therapy for mets to see if it correlates with their other markers and scan results. This is how I see its value developing.

Perhaps other blood tests for cancer cells will come out of development and be more accurate/reliable. etc., but in the meantime I want to use whatever is NOW available to monitor my cancer situation.