High HER-2 protein levels correlate with clinicopathological features in colorectal cancer

HER2 targeted therapy in colorectal Cancer: Current landscape and future directions

Colorectal cancer (CRC) is one of the most common causes of tumor-related deaths globally. Despite recent improvements in the comprehensive therapy of malignancy, metastatic CRC continues to have a poor prognosis. Human epidermal growth factor receptor 2 (HER2) is an established oncogenic driver, which is successfully targeted for breast and gastric cancers. Approximately 5% of CRC patients carry somatic HER2 mutations or gene amplification. In 2019, the U.S. Food and Drug Administration have approved trastuzumab and pertuzumab in combination with chemotherapy for the treatment of HER2-positive metastatic CRC. This approval marked a significant milestone in the treatment of CRC, as HER2-positive patients now have access to targeted therapies that can improve their outcomes. Yet, assessment for HER2 overexpression/ amplification in CRC has not been standardized. The resistance mechanisms to anti-HER2 therapy have been not clearly investigated in CRC. Although many unknowns remain, an improved understanding of these anti-HER2 agents will be essential for advanced CRC. In this review, we provide an overview of the role of HER2 in CRC as an oncogenic driver, a prognostic and predictive biomarker, and a clinically actionable target, as well as the current progress and challenges in the field.

Quantitative parameters of magnetic resonance imaging cannot predict human epidermal growth factor receptor 2 (HER2) status in rectal cancer

PURPOSE

To retrospectively investigate whether magnetic resonance imaging (MRI) quantitative parameters can differentiate human epidermal growth factor receptor 2 (HER2) status in rectal cancer.

MATERIALS AND METHODS

This study included 89 patients with surgically confirmed rectal cancer who underwent preoperative MRI from June 2014 to May 2019. Patients were divided into three groups: HER2 negative (HER2-Neg); HER2-low expression (HER2-L); and HER2 positive (HER2-Pos). Quantitative perfusion parameters derived from dynamic contrast-enhanced MRI (DCE-MRI) Tofts model (pharmacokinetic blood dual compartment model) were listed as follows: volume transfer constant (K^trans), rate constant (K_ep), and extracellular volume ratio (V_e). The mean, minimum, and maximum apparent diffusion coefficient (ADC) values at standard (800 s/mm²) b-values were obtained with diffusion-weighted imaging (DWI). Clinicopathologic characteristics and quantitative parameters were compared by Fisher's exact test and one-way analysis of variance (ANOVA), respectively.

RESULTS

The 89 patients included 52 (58.4%) with HER2-Neg, 31 (34.8%) with HER2-L, and 6 (6.8%) with HER2-Pos states. Fisher's exact test showed that clinicopathologic characteristics among the three groups were not significantly different (p = 0.281 to 1.000). Likewise, there were no associations between HER2 status and any quantitative parameters, including K^trans (p = 0.296), K_ep (p = 0.290), V_e (p = 0.184), ADC_mean (p = 0.181), ADC_min (p = 0.143), or ADC_max (p = 0.058).

CONCLUSION

Quantitative perfusion parameters (K^trans, K_ep, V_e) and ADC values were not able to discriminate HER2 status in patients with rectal cancer or evaluate treatment response in real time.

HER2 Overexpression and Mismatch Repair Deficiency are Correlated with Malignancy in Colorectal Cancer

PURPOSE

This study was designed to investigate the correlation between the expression of human epidermal growth factor receptor 2 (HER2), mismatch repair (MMR), and clinicopathological parameters and serum tumor markers in a total of 522 resection samples materials from colorectal cancer (CRC) patients. These data were also used to determine the links between HER2 and MMR expression and prognosis.

METHODS

We conducted a retrospective analysis of the clinical data from 522 CRC patients. Immunohistochemistry (IHC) was used to detect HER2 overexpression and MMR deficiency (dMMR) in tumor specimens which were then correlated with various clinicopathological parameters. Prognostic value for HER2 and MMR expression was then evaluated using the data from 105 CRC patients.

RESULTS

HER2 overexpression was identified in 35.63% of the samples evaluated in this study, while the total dMMR rate was 12.64%. Expression of HER2 and several, MMR proteins (MLH1, MSH-2, MSH-6, and PMS-2) were then correlated with tumor location. HER2 overexpression is significantly associated with increased depth of tumor invasion, lymph node metastasis, distant metastases, pTNM staging, vascular invasion, nerve infiltration, and serum carcinoembryonic antigen (CEA) levels. HER2 overexpression and dMMR increased with advancing clinical stage. In addition, deficiencies in MLH1 and PMS2 correlated with HER2 overexpression. Finally, the prognostic evaluations revealed that HER2 overexpression was closely associated with poorer clinical outcomes.

CONCLUSION

HER2 overexpression is significantly correlated with multiple clinicopathological parameters resulting in a poorer prognosis. Moreover, the prognosis of patients with HER2 overexpression was worse, confirming its significance during disease assessment. In clinical practice, clinicians should pay close attention to the HER2 profile of patients as they may require more extensive clinical intervention. In addition, deficiencies in MLH1, MSH-2, MSH-6, or PMS-2 correlate with tumor location, and MLH1 and PMS2 expression is associated with lymph node metastasis and pTNM stage, suggesting that these may be additional markers in CRC risk assessments.

HER2 and BRAF mutation in colorectal cancer patients: a retrospective study in Eastern China

Objective

To investigate the frequency and prognostic role of the human epidermal growth factor receptor 2 gene (HER2) and BRAF V600E gene mutation in Chinese patients with colorectal cancer (CRC).

Methods

Clinicopathological and survival information from 480 patients with stage I–III CRC were reviewed and recorded. HER2 amplification was analyzed by immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH), BRAF V600E mutation was tested by IHC and Sanger sequencing. The relationship between HER2 and BRAF V600E mutation status and clinicopathological characteristics and outcomes were determined.

Results

The amplification of HER2 and BRAF V600E mutation were identified in 27 of 480 (5.63%) and 19 of 480 (3.96%) CRC patients, respectively. HER2 amplification significantly correlated with greater bowel wall invasion (P = 0.041) and more advanced TNM stage (I vs. II vs. III; 0 vs 5.78% vs. 7.41%, P = 0.013). Patients suffering from tumors with poor differentiation had a higher incidence rate of BRAF V600E mutation than those with moderate/well differentiation (7.77% vs 2.92%, P = 0.04). HER2 amplification was an independent prognostic factor for worse disease-free survival (DFS) (HR = 2.53, 95% CI: 1.21–5.30, P = 0.014).

Conclusion

The prevalence of HER2 amplification and BRAF V600E mutation in stage I–III CRC patients in Chinese was 6% and 4%, respectively, and HER2 amplification appeared to be associated with a worse DFS. More comprehensive molecular classification and survival analysis are needed to validate our findings.

Assessment of two different HER2 scoring systems and clinical relevance for colorectal cancer

Although the positivity of human epidermal growth factor receptor 2 (HER2) is low in colorectal cancer (CRC), anti-HER2 is becoming a new target therapy in metastatic colorectal cancer (mCRC). However, assessment of the HER2 scoring system was still not established in CRC. The purpose of our study was to evaluate HER2 status and its correlation with clinicopathological characteristics and survival according to the HER2 diagnostic criteria for gastroesophageal adenocarcinoma (GEA criteria) and the HERACLES diagnostic criteria (HERACLES criteria) in a large cohort of Chinese CRC patients. The HER2 positivity was 2.9% (43/1490) and 2.6% (39/1490) in CRCs based on the GEA criteria and the HERACLES criteria, and 3.7% (9/243) in mCRC according to both criteria. HER2 status was associated with primary tumor location (P = 0.037), regional lymph node metastasis (P = 0.035), and TNM stage (P = 0.022) in CRCs based on the HERACLES criteria. No such association was found based on the GEA criteria. Furthermore, HER2 positive only presented in patients with RAS gene wild type (P = 0.001). Significant difference was only observed between the HER2-positive and HER2-negative groups in terms of disease-free survival for stage II-III CRCs (P = 0.048) according to the HERACLES criteria, but not based on the GEA criteria. Our findings suggest that the frequency of HER2 overexpression or amplification was low in Chinese CRC patients, and provide a rationale for further evaluation of HER2 in CRC based on the HERACLES criteria and the HER2 diagnostic criteria for gastroesophageal adenocarcinoma.

Overcoming Intrinsic and Acquired Cetuximab Resistance in RAS Wild-Type Colorectal Cancer: An In Vitro Study on the Expression of HER Receptors and the Potential of Afatinib

The epidermal growth factor receptor (EGFR) is an important therapeutic target in colorectal cancer (CRC). After the initial promising results of EGFR-targeted therapies such as cetuximab, therapeutic resistance poses a challenging problem and limits the success of effective anti-EGFR cancer therapies in the clinic. In order to overcome resistance to these EGFR-targeted therapies, new treatment options are necessary. The objective of this study was to investigate the expression of human epidermal growth factor (HER) receptors and the efficacy of afatinib, a second-generation irreversible EGFR-tyrosine kinase inhibitor, in RAS wild-type CRC cell lines with different cetuximab sensitivities. CRC cell lines with different sensitivities to cetuximab showed rather low EGFR expression but high HER2 and HER3 expression. These results were in line with the The Cancer Genome Atlas (TCGA) data from CRC patients, where higher mRNA levels of HER2 and HER3 were also detected compared to EGFR. Therefore, the targets of afatinib were indeed expressed on the CRC cell lines used in this study and in CRC patients. Furthermore, cetuximab resistance had no significant influence on the expression levels of HER receptors in CRC cell lines (p ≥ 0.652). This study also demonstrated that afatinib was able to induce a concentration-dependent cytotoxic effect in RAS wild-type CRC cell lines with different cetuximab sensitivities. Neither cetuximab resistance (p = 0.233) nor hypoxia (p = 0.157) significantly influenced afatinib’s cytotoxic effect. In conclusion, our preclinical data support the hypothesis that treatment with afatinib might be a promising novel therapeutic strategy for CRC patients experiencing intrinsic and acquired cetuximab resistance.

HER2-targeted therapy: an emerging strategy in advanced colorectal cancer

INTRODUCTION

Colorectal cancer (CRC) is one of the most common malignant tumors; it is a focus of research globally, but the identification of clinically actionable oncogenic drivers remains elusive. Human epidermal growth factor receptor 2 (HER2) activation is present in approximately 5% of CRC and has acquired resistance to epidermal growth factor receptor (EGFR)-targeted therapy. Early clinical trials suggest an emerging role for personalized HER2-targeted therapy in a subset of metastatic CRC.

AREAS COVERED

This manuscript reviews the relevance of HER2 activation in CRC and its potential role as a target for therapy. A literature search was conducted in June 2018 of MEDLINE and EMBASE databases for published preclinical and clinical studies; abstracts of international cancer meetings (AACR, ASCO, and ESMO) were also reviewed.

EXPERT OPINION

HER2 is activated in a small but relevant proportion of CRC patients (particularly left-side, RAS wild-type, anti-EGFR resistant tumors). Dual HER2 blockade with monoclonal antibodies (mAbs) (trastuzumab and pertuzumab) or the combination of mAbs with tyrosine kinase inhibitors (trastuzumab and lapatinib) induces durable tumor responses in about one-third of HER2-positive CRC refractory to standard systemic therapy. Although immature, these results are remarkable and anticipate an expanding role for HER2 as a therapeutic target in CRC.

Targeting the human epidermal growth factor receptor 2 (HER2) oncogene in colorectal cancer

Human epidermal growth factor receptor 2 (HER2) is an oncogenic driver, and a well-established therapeutic target in breast and gastric cancers. Using functional and genomic analyses of patient-derived xenografts, we previously showed that a subset (approximately 5%) of metastatic colorectal cancer (CRC) tumors is driven by amplification or mutation of HER2. This paper reviews the role of HER2 amplification as an oncogenic driver, a prognostic and predictive biomarker, and a clinically actionable target in CRC, considering the specifics of HER2 testing in this tumor type. While the role of HER2 as a biomarker for prognosis in CRC remains uncertain, its relevance as a therapeutic target has been established. Indeed, independent studies documented substantial clinical benefit in patients treated with biomarker-driven HER2-targeted therapies, with an impact on response rates and duration of response that compared favorably with immunotherapy and other examples of precision oncology. HER2-targeted therapeutic strategies have the potential to change the treatment paradigm for a clinically relevant subgroup of metastatic CRC patients.