EGFR and HER3 expression in circulating tumor cells and tumor tissue from non-small cell lung cancer patients

Heather Scharpenseel,Harriet Wikman,Christian Bernreuther,Malte Mohme,Sven Peine,Klaus Pantel,Cordula Petersen,Sabine Riethdorf,Yvonne Goy,Markus Glatzel,Manfred Westphal,Katrin Lamszus,Sonja Loges,Annkathrin Hanssen

doi:10.1038/s41598-019-43678-6

Heather Scharpenseel, Harriet Wikman + Show 12 more

Open Access

https://doi.org/10.1038/s41598-019-43678-6

Copy DOI

Abstract

Although clinically relevant, the detection rates of EpCAM positive CTCs in non-small cell lung cancer (NSCLC) are surprisingly low. To find new clinically informative markers for CTC detection in NSCLC, the expression of EGFR and HER3 was first analyzed in NSCLC tissue (n = 148). A positive EGFR and HER3 staining was observed in 52.3% and 82.7% of the primary tumors, and in 62.7% and 91.2% of brain metastases, respectively. Only 3.0% of the brain metastases samples were negative for both HER3 and EGFR proteins, indicating that the majority of metastases express these ERBB proteins, which were therefore chosen for CTC enrichment using magnetic cell-separation. Enrichment based on either EGFR or HER3 detected CTCs in 37.8% of the patients, while the combination of EGFR/HER3 enrichment with the EpCAM-based CellSearch technique detected a significantly higher number of 66.7% CTC-positive patients (Cohen’s kappa = −0.280) which underlines the existence of different CTC subpopulations in NSCLC. The malignant origin of keratin-positive/CD45-negative CTC clusters and single CTCs detected after EGFR/HER3 based enrichment was documented by the detection of NSCLC-associated mutations. In conclusion, EGFR and HER3 expression in metastasized NSCLC patients have considerable value for CTC isolation plus multiple markers can provide a novel liquid biopsy approach.

Highlights

Clinically relevant, the detection rates of EpCAM positive circulating tumor cell (CTC) in non-small cell lung cancer (NSCLC) are surprisingly low
Tissue microarrays (TMA) with 55 surgical tissue specimens from histologically proven NSCLC primary tumors, 17 matched lymph node metastases and 76 non-matched lung cancer brain metastases were used for immunohistochemistry (IHC) staining of EGFR and HER3 proteins
Others and we have previously shown that important tumor markers from the ERRB-family can be upregulated in CTCs and metastatic tissue compared to the primary tumor[24,25]

Summary

Introduction

The detection rates of EpCAM positive CTCs in non-small cell lung cancer (NSCLC) are surprisingly low. To find new clinically informative markers for CTC detection in NSCLC, the expression of EGFR and HER3 was first analyzed in NSCLC tissue (n = 148). EGFR and HER3 expression in metastasized NSCLC patients have considerable value for CTC isolation plus multiple markers can provide a novel liquid biopsy approach. With the most commonly used EpCAM based CTC detection systems the CTC detection rate in NSCLC patients is surprisingly low, especially when considering the aggressiveness of the disease[10]. 10–15% of Caucasian lung adenocarcinoma patients and up to 40% of patients of Asian origin carry an activating mutation of the EGF-receptor (EGFR)[17] These patients can efficiently be treated with different small molecule inhibitors (tyrosine kinase inhibitors) targeting EGFR18. We developed a CTC detection technique using these two markers and show that in combination with EpCAM we could capture a larger fraction of CTCs in NSCLC patients

Methods

Results

Conclusion