Efficacy of anti-HER2 therapy in metastatic breast cancer by discordance of HER2 expression between primary and metastatic breast cancer
- PMID: 32980945
- DOI: 10.1007/s10549-020-05935-5
Efficacy of anti-HER2 therapy in metastatic breast cancer by discordance of HER2 expression between primary and metastatic breast cancer
Abstract
Purpose: In stage IV breast cancer, the efficacy of human epidermal growth factor receptor 2 (HER2) targeted therapies in cases with discordance in HER2 expression between primary and metastatic site is not well known. We studied progression free (PFS) and overall survival (OS) by HER2 concordance when treating women with taxane-trastuzumab (± pertuzumab) in first or second line and trastuzumab-emtansine (T-DM1) or capecitabine-lapatinib in later lines.
Patients and methods: Retrospective monocentric study including all breast cancer patients receiving trastuzumab between January 2002 and September 2017 at the University Hospital in Leuven; we selected metastatic patients with an available HER2 status in primary and metastatic site. The Kaplan-Meier method was used for estimating PFS/OS and log-rank test for analyzing between group differences. A Cox model is used for testing difference between groups while correcting for Pertuzumab. Multivariable Cox regression is used to model overall survival as a function group, correcting for possible confounders.
Results: We included 74 patients; 46 had an unchanged HER2 status (positive/positive), 9 lost HER2 (positive/negative), while 19 acquired HER2 amplification (negative/positive). 25 out of 28 cases with a discordant HER2 status were positive for ER and/or PgR in the primary site. HER2 positive/negative cases had a significantly lower PFS for taxane-trastuzumab-(pertuzumab) (PFS = 5.5 months), compared to HER2 positive/positive (PFS 9 months, p = 0.01) and HER2 negative/positive (PFS 14 months, p = 0.01) patients. PFS for later line T-DM1 (n = 30) was significantly higher for the HER2 positive/positive group (PFS 6.0 months) than for the discordant groups HER2 negative/positive (PFS 1.0 month, p = 0.04) and HER2 positive/negative (PFS 1.5 month, p = 0.01). After correcting for possible confounders, the HER2 positive/negative group had a significantly worse OS compared to HER2 positive/positive (HR 0.19, 95% CI 0.08-0.44) and negative/positive (HR 0.15, 95% 0.06-0.38).
Conclusion: Conversion of HER2 status was seen in 28 out of 74 cases and was mostly observed in hormone receptor-positive tumors. In contrast to patients with HER2 loss, patients with a positive conversion of HER2 status derived substantial benefit from first line treatment with taxane-trastuzumab-(pertuzumab). This study highlights the importance of re-biopsying the metastatic lesion and changing treatment according to the last HER2 result.
Keywords: Biopsy; Breast cancer; Discordance; HER2 receptor; HER2/CEP17 ratio; Metastasis; Survival.
References
-
- Slamon DJ, Godolphin W, Jones LA, Holt JA, Wong SG, Keith DE, Levin WJ, Stuart SG, Udove J, Ullrich A et al (1989) Studies of the HER-2/neu proto-oncogene in human breast and ovarian cancer. Science 244:707–712 - DOI
-
- Ross JS, Slodkowska EA, Symmans WF, Pusztai L, Ravdin PM, Hortobagyi GN (2009) The HER-2 receptor and breast cancer: ten years of targeted anti-HER-2 therapy and personalized medicine. Oncologist 14(4):320–368 - DOI
-
- Yao Z, Lu L, Wang R, Jin L, Liu S, Li H et al (2013) Discordance and clinical significance of ER, PR, and HER2 status between primary breast cancer and synchronous axillary lymph node metastasis. Med Oncol 31(1):798 - DOI
-
- Gajria D, Chandarlapaty S (2011) HER2-amplified breast cancer: mechanisms of trastuzumab resistance and novel targeted therapies. Expert Rev Anticancer Ther 11(2):263–275 - DOI
-
- Amir E, Miller N, Geddie W, Freedman O, Kassam F, Simmons C et al (2012) Prospective study evaluating the impact of tissue confirmation of metastatic disease in patients with breast cancer. J Clin Oncol 30(6):587–592 - DOI
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