Fussy IHC and FISH Test result on Herceptin decision

[xiang888]

Hi, dear expert
my sister has breast cancer test with IHC 3+ followed by FISH test result of HER2 absolut no. of copy 3.92 and HER2/Chr17 with 1.96. Since the values are all on the borderline, even the result of IHC 3+ is somehow approximated. What is the expert opinion on whether she should use herceptin or not with this result ? Should she make another tests, if yes, what tests ? My sister lives in China.

Thanks a lot for the help and advice
Xiang888

[bluebutterfly2222]

p.s. Here are the tests and what is considered a positive result for each one:

•IHC: ImmunoHistoChemistry - this test measures the production of the HER2 protein by the tumor. The test results are ranked as 0, 1+, 2+, or 3+. If the results are 3+, your cancer is HER2-positive.
•FISH: Fluorescence In Situ Hybridization - this test uses fluorescent probes to look at the number of HER2 gene copies in a tumor cell. If there are more than 2 copies of the HER2 gene, then the cancer is HER2 positive.

[bluebutterfly2222]

What has her oncologist advised?

The FISH test is the more accurate ot the two tests.

The FISH test results will tell you that the cancer is either “positive” or “negative” (a result sometimes reported as “zero”) for HER2.

If your sister's FISH test was positive, she should  be treated with Herceptin.

Best wishes to you both...