Table 8.

HER2: comments from the working group.

Comments
- Consider HER2 testing in advanced/recurrent endometrial serous carcinoma and in the mixed forms with serous component - In mixed carcinomas, HER2 testing should be performed on a tissue block containing the highest amount of serous component - For other high-grade histologies, we propose to introduce HER2 testing only with a scientific intent - The first method for HER2 testing is represented by HER2 IHC - Molecular reflex test (FISH/SISH) is indicated in case of equivocal (2+) IHC results - Standardize pre-analytical and analytical protocol of testing - IHC can be performed on biopsies or surgical specimens if available, preferring the best-preserved sample as first choice
The main advantages of performing IHC on biopsies are the following:
(i) the better degree of fixation of biopsies (ii) the early knowledge of HER2 status in a pre-operative setting
The main advantages of performing IHC on surgical sample are the following:
(i) larger amount of tumoral representative tissue (ii) the possibility to select the best specimen for IHC testing (iii) the possibility to overcome tumor heterogeneity