Here's the abstract from SABC on her2 status change.I would like to have seen this in a bigger cohort; however, I think similar findings have been found in other research that I have read.
[2019] Concordance of HER2 and hormone receptor expression in primary and recurrent breast cancer.
Wirk B, Geiger X, Hillman D, Perez EA. Mayo Clinic, Jacksonville, FL
Background: Determination of accurate HER2 and hormone receptor status is of primary importance in breast cancer treatment. Concordance of expression of these 2 prognostic and predictive factors between primary and recurrent tumors provide guidance related to the potential need to re-biopsy patients at the time of recurrence, or managing them based on the characteristics of the original tumor.
Methods: Retrospective review of all medical records available of patients (pts) with recurrent breast cancer between 1997 and 2003 (160 cases total) at a single institution as to whether expression levels of HER2 by immunohistochemistry (IHC) using HercepTestTM or fluorescence in situ hybridization (FISH) using PathvysionTM as well as ER (estrogen receptor) and PR (progesterone receptor) by nuclear staining differ in the primary tumor and the asynchronous recurrent lesions.
Results: Out of 160 cases, 39 pts (ages 41-85 years) had HER2 status available on the primary breast cancer and biopsies of the asynchronous recurrent breast cancer lesions. 8 (20.5%;95% CI 7.8-33.2%) pts had HER2 status conversion (table 1). 7 pts with HER2 status conversion had HER2 status determination by HercepTest and 1 patient had FISH. All pts with HER2 concordance had HercepTests. 14 (35.9%; 95% CI:20.8-51%) pts had ER/ PR status conversion from the primary breast cancer to the recurrent breast cancer (table 2). Of those pts with HER2 status conversion, the disease free interval (DFI) was 10 to 45 months. Of those with HER2 status concordance, the DFI was 9 months to 12 years. 7 of the 8 pts with HER2 status conversion had locoregional recurrence (with biopsies of the breast [4 pts], axillary lymph node [2 pts], chest wall [1 pt]) and 1 had distant recurrence (biopsy of the bone). 3 of 8 pts with HER2 status conversion had ER and PR status conversion (ie ER+ or PR+ status of the primary breast cancer and ER- PR- status of the asynchronous recurrent breast cancer). 4 of the 8 pts with HER2 status conversions received anthracycline based chemotherapy and tamoxifen; 1 of the 8 pts received tamoxifen alone; 3 of the 8 pts received chemotherapy alone and 6 of the 8 pts received radiation for their primary breast cancer.
Conclusions: Changes in HER2 (20.5%) and hormone receptor expression (35.9%) were found between the primary and asynchronous recurrent breast cancer. Pts with recurrent breast cancer should have new biopsies performed to best determine whether therapy with trastuzumab and/or antiestrogen therapy is indicated. Only 39 of 160 recurrent breast cancers examined between 1997-2003 had biopsies of the recurrent lesions and data regarding the 2004 metastatic breast cancer cases are forthcoming.
Table 1. Number of patients Primary breast cancer HER2 Recurrent breast cancer HER2 4 HER2 2+ IHC HER2 0 IHC 1 HER2 3+ IHC HER2 1+ IHC 2 HER2 0 IHC HER2 3+ IHC 1 HER2 FISH amplification HER2 no FISH amplification
Table 2 Number of patients Primary breast cancer ER PR Recurrent breast cancer ER PR 7 ER+ or PR+ ER- PR- 2 ER- PR- ER+ PR+ 4 ER+ PR+ ER+ PR- 1 ER- PR- ER- PR+
Friday, December 9, 2005 7:00 AM
Poster Session II: Detection and Diagnosis: Diagnostic Pathology (7:00 AM-9:00 AM)