HER2 Amplification In Patients Research Articles

Prevalence and Therapeutic Targeting of High-Level ERBB2 Amplification in NSCLC

IntroductionERBB2 amplification in lung cancer remains poorly characterized. HER2 (encoded by ERBB2) is a transmembrane tyrosine kinase capable of ligand-independent dimerization and signaling when overexpressed, and a common cause of HER2 overexpression is ERBB2 amplification. Here, we evaluated the clinicopathologic and genomic characteristics of ERBB2-amplified NSCLC and explored a HER2 antibody–drug conjugate (ADC) therapeutic strategy. MethodsOur institutional next-generation DNA sequencing data (OncoPanel) from 5769 NSCLC samples (5075 patients) were queried for cases having high-level ERBB2 amplification (≥6 copies). Clinical and demographic characteristics were extracted from the electronic medical records. Efficacy of the pan-ERBB inhibitor afatinib or HER2 ADCs (trastuzumab deruxtecan and trastuzumab emtansine) was evaluated in NSCLC preclinical models and patients with ERBB2 amplification. ResultsHigh-level ERBB2 amplification was identified in 0.9% of lung adenocarcinomas and reliably predicted overexpression of HER2. ERBB2 amplification events are detected in two distinct clinicopathologic and genomic subsets of NSCLC: as the sole mitogenic driver in tumors arising in patients with a smoking history or as a concomitant alteration with other mitogenic drivers in patients with a light or never smoking history. We further reveal that trastuzumab deruxtecan is effective therapy in in vitro and in vivo preclinical models of NSCLC harboring ERBB2 amplification and report two cases of clinical activity of an anti-HER2 ADC in patients who acquired ERBB2 amplification after previous targeted therapy. ConclusionsHigh-level ERBB2 amplification reliably predicts HER2 overexpression in patients with NSCLC, and HER2 ADC is effective therapy in this population.

Abstract P4-02-14: Gain of HER2 Amplification in Patients with HR+/HER2- and Triple Negative Early Breast Cancer Treated with Neoadjuvant Chemotherapy

Abstract Background: Neoadjuvant chemotherapy (NAC) is standard of care for the majority of patients with clinical stage II-III triple negative breast cancer (TNBC) and is considered in high-risk patients with hormone receptor positive (HR+)/human epidermal growth factor receptor 2 (HER2) negative (-) tumors, with expected pathological complete response (pCR) rates of 40-60% and 10-12%, respectively. In HER2- patients with residual disease (RD) after NAC, there is limited data on rates of gain of HER2 amplification. The biological and clinical significance of this phenomenon is unknown and determining the best adjuvant therapy for these patients remains a challenge. We sought to determine the rate of HER2 gain in a cohort of consecutive patients with HER2- breast cancer (BC) treated with NAC. Methods: From 01/2021 to 12/2021, we identified patients with HER2- breast cancer treated with NAC followed by surgery at our institution. Patients who received neoadjuvant endocrine therapy were excluded. The rates of pCR (ypT0/is ypN0) and HER2 status pre- and post-NAC were assessed. Estrogen receptor (ER), progesterone receptor (PR) and HER2 status on surgery specimens were internally determined for all patients using ASCO/CAP 2020 guidelines. ER-low was defined as ER expression by immunohistochemistry (IHC) 1-10%. Results: We included 256 patients, 130 (51%) HR+/HER2- [13/130(10%) ER-low] and 126 (49%) TNBC. Median age was 48 years (range 25-82) and the majority presented with clinical T2 (57%) and N1 (59%). Of 130 patients with HR+/HER2-tumors, 120 (92%) received dose-dense (dd) doxorubicin/cyclophosphamide-paclitaxel (AC-T). Of 126 TNBC patients, 46 (37%) received ddAC followed by carboplatin in combination with paclitaxel +/- pembrolizumab. Centralized HER2 status assessment on the core biopsy was performed in 22% of samples. Overall, pCR was achieved in 40% of TNBC and 11% of HR+/HER2-. Among the 192 patients with RD, the rate of HER2 gain was 8/192 (4%), including 3% (2/76) of TNBC and 5% (6/116) of HR+/HER2- patients. 7 of the 8 patients (88%) converted from IHC 1+ or 2+ fluorescence in situ hybridization (FISH) not amplified on core biopsy to IHC 2+ FISH amplified on the surgical specimen. In only 1 case, the HER2 status converted from IHC2+ FISH not amplified to IHC3+. 3/8 patients had multifocal disease. All 6 patients with HR+/HER2- BC and HER2 gain had high (>90%) ER expression (Table 1). All but one patient with HER2 gain received adjuvant anti-HER2 therapy. After a median follow-up of 10 months, no recurrence events occurred in this group.12 of the remaining 184 patients experienced a recurrence [11 distant recurrences (8 and 3, in the TNBC and HR+/HER2- groups, respectively), and there was 1 local event (localized chest wall recurrence) in the HR+/HER2- group]. Conclusions: At a single center, we found that in patients with HER2- BC treated with NAC, HER2 gain in patients with RD was uncommon and occurred more frequently in those with HR+ tumors. Analysis of a larger cohort is ongoing to corroborate these results. It is remains to be determined if this phenomenon represents a true HER2 status conversion or tumor heterogeneity. Table 1: Clinico-pathological characteristics of patients with HER2 gain on residual disease Citation Format: Emanuela Ferraro, Sonya Chew Minmin, Anton Safonov, Andrea V. Barrio, Shanu Modi, Andrew D Seidman, Hanna Y Wen, Edi Brogi, Mark E. Robson, Chau T Dang. Gain of HER2 Amplification in Patients with HR+/HER2- and Triple Negative Early Breast Cancer Treated with Neoadjuvant Chemotherapy [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P4-02-14.

Abstract 3986: Digital droplet PCR measurement for plasma HER2 amplification in patients with AGC

Abstract Introduction: With the recent introduction of human epidermal growth factor receptor 2 (HER2) targeted therapies for patients with advanced gastric cancer (AGC), determining HER2 status is essential to select the patients who may benefit from this treatment. The current standard method assessing HER2 positivity is immunohistochemistry (IHC) or in situ hybridization assays, but this way of HER2 assessment has weaknesses especially when considering tumor heterogeneity. Using digital droplet polymerase chain reaction (ddPCR) technique, we evaluated HER2 amplification in both tissue and plasma samples collected from AGC patients and analyzed clinical implication of HER2 amplification in circulating tumor DNA. Method: Biopsied tissue and plasma samples were collected from patients with metastatic or recurrent AGC who were enrolled in AGC biomarker study conducted at Asan Medical Center. Samples were obtained before the start of anti-cancer treatment. HER2 amplification in DNA from tissue and cell-free DNA from plasma were determined by ddPCR, performed in Kindai University. Results: Samples of 63 patients with HER2 positive GC and 37 patients with HER2 negative GC enrolled between April 2014 and October 2017 were included in the analysis. As expected, the median HER2 copy number (CN) was higher in patients diagnosed as HER2 positive than negative, both for tissue (4.54 vs 0.95, P < 0.001) and plasma (1.49 vs 1.07, P < 0.001). ROC curve analysis showed 83.8% specificity and 69.8% sensitivity for tissue HER2 positivity at 1.17 CN of plasma HER2. In patients receiving anti-HER2 therapy (n=57), there was a trend for worse progression-free survival (PFS) outcome in patients with higher plasma HER2 CN (>1.5 vs ≤1.5), although no statistical significance was seen (median PFS 6.67 vs 8.19 months, P = 0.172). In multivariate Cox regression analysis including the age (>60 vs ≤60), HER2 IHC intensities (2+ vs 3+), and risk groups determined by Koo et al.’s prognostic model (Good vs Moderate vs Poor), higher plasma HER2 CN (>1.5 vs ≤1.5) was significantly associated with poor PFS (HR 2.22, 95% CI 1.14-4.32, P = 0.019). However, when tumor burden (sum of largest diameter of all measurable lesions) was combined as another factor in patients with measurable disease (n=39), plasma HER2 CN was no longer an independent factor (HR 1.38, 95% CI 0.58-3.27, P = 0.466) and larger tumor burden (>6.5cm vs ≤6.5cm) was found to be an independent prognostic factor for poor PFS (HR 2.63, 95% CI 1.12-6.21, P = 0.027), instead. Of note, plasma HER2 CN showed a positive relationship with tumor burden multiplied by tissue HER2 CN in linear regression (β=0.32, P = 0.002). Conclusion: Using the ddPCR technique, we found that plasma HER2 CN was significantly increased in HER2 positive GC patients compared to negative patients. However, plasma HER2 CN did not provide more information on predicting therapeutic effects than the tumor burden in patients receiving anti-HER2 therapy. Citation Format: Kyoungmin Lee, Kazuko Sakai, Min-Hee Ryu, Jae-Joon Kim, Young Soo Park, Young-Soon Na, Jungeun Ma, Hana Na, Kazuto Nishio, Yoon-Koo Kang. Digital droplet PCR measurement for plasma HER2 amplification in patients with AGC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3986.

Prognostic and Predictive Value of HER2 Amplification in Patients With Metastatic Colorectal Cancer

PurposeTo evaluate a prognostic and predictive value of HER2 amplification in patients with metastatic colorectal cancer (mCRC). Patients and MethodsPatients with mCRC who underwent surgical resection of the primary tumor and who received best supportive care with or without palliative chemotherapy between 2005 and 2015 were included. HER2 immunohistochemistry was performed using formalin-fixed, paraffin-embedded primary tumor specimens. HER2 amplification was confirmed by fluorescence in-situ hybridization. The RAS and BRAFV600E mutations were centrally assessed using a PCR-based method. Patients were divided into 4 subgroups: R (RAS mutant), B (BRAFV600E mutant), H (wild-type RAS/BRAF with HER2 amplification), and W (wild-type RAS/BRAF without HER2 amplification). Overall survival (OS) and progression-free survival of anti–epidermal growth factor receptor (EGFR) therapy were assessed. ResultsAmong 370 eligible patients, data of 359 were successfully analyzed. Fifteen tumors harbored HER2 amplifications, including 4 tumors with concomitant RAS mutation (group R). The number of patients in groups R, B, H, and W was 204, 13, 11, and 131, respectively. The median OS was 27.4 months, and the median follow-up time was 63.2 months. The median OS for groups R, B, H, and W was 24.0, 14.2, 19.9, and 39.1 months, respectively. The number of patients who received anti-EGFR therapy in groups R, B, H, and W was 17, 4, 5, and 49, respectively. Progression-free survival of anti-EGFR therapy was significantly shorter in groups R, B, and H than in group W. ConclusionHER2 amplification was predictive of anti-EGFR therapy response and appeared to be prognostic in mCRC patients.

P260 - Association of Interleukin-22 expression with HER-2 amplification in patients with breast cancer

P260 - Association of Interleukin-22 expression with HER-2 amplification in patients with breast cancer

Abstract 509: HER2 genomic amplification in circulating tumor DNA from patients with cetuximab-resistant colorectal cancer

Abstract Background: Patients with metastatic colorectal cancer (mCRC) harboring wild-type KRAS benefit from epidermal growth factor receptor (EGFR)-targeted therapy. However, patients who are treated with anti-EGFR antibodies will eventually develop the resistance to those agents. We previously found that HER2 amplification was one of the mechanisms conferring resistance to anti-EGFR antibody therapy and could therefore be a potential therapeutic target (Yonesaka et al, STM 2011). The aim of this study was to detect HER2 amplification in circulating tumor DNA (ctDNA) from patients with CRC and acquired resistance to anti-EGFR antibody therapy. Methods: We analyzed plasma ctDNA using digital polymerase chain reaction (PCR) from 18 patients with CRC, who had been treated with anti-EGFR antibody-based therapy (cetuximab) and subsequently acquired resistant cetuximab. We aimed to obtain at least 100 droplets for HER2 and EFTUD2 to accurately assess the ratio. Digital PCR data were analyzed using the QuantaSoft analytical software package (Bio-Rad). The copy number concentration of each gene (HER2 and EFTUD2) was estimated from the Poisson distribution. HER2 amplification with digital PCR was defined as a HER2 ratio (HER2/EFTUD2 copy number ratio) of 1.25 accordingly (Gevensleven H et al, CCR 2013). HER2 gene copy number was analyzed using fluorescence in situ hybridization also in tumor samples before and after acquisition of resistance to cetuximab-based therapy. Results: Our data showed various HER2 copy number in plasma ctDNA from CRC patients (median: 1.09; range: 0.94-5.18). 22% (4/18) of patients in the cohort exhibited HER2 amplification. One of these patients was found to be positive for HER2 amplification in matched tumor specimens collected after cetuximab therapy, at which point the patient had acquired cetuximab resistance, despite being negative for HER2 amplification prior to therapy (pre: 1.14, post: 2.78). Conclusion: Analysis of plasma ctDNA by digital PCR could be useful for detecting HER2 amplification in patients with CRC who were resistant to anti-EGFR antibody therapy. We are now conducting another, large-scale study for evaluating HER2 amplification by ctDNA in CRC patients using digital PCR. Citation Format: NAOKI TAKEGAWA. HER2 genomic amplification in circulating tumor DNA from patients with cetuximab-resistant colorectal cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 509.

HER2 genomic amplification in circulating tumor DNA from patients with cetuximab-resistant colorectal cancer.

BackgroundPatients with metastatic colorectal cancer (mCRC) harboring wild-type KRAS benefit from epidermal growth factor receptor (EGFR)-targeted therapy. However, patients who are treated with anti-EGFR antibodies will eventually develop the resistance to those agents. HER2 amplification is one of the mechanisms conferring resistance to anti-EGFR antibody therapy and could therefore be a potential therapeutic target. The aim of this study was to detect HER2 amplification in circulating tumor DNA (ctDNA) from patients with CRC and acquired resistance to anti-EGFR antibody therapy.ResultsOur data showed that 22% (4/18) of patients in the cohort exhibited HER2 amplification. One of these patients was found to be positive for HER2 amplification in matched tumor specimens collected after cetuximab therapy, at which point the patient had acquired cetuximab resistance, despite being negative for HER2 amplification prior to therapy.MethodsWe analyzed plasma ctDNA using digital polymerase chain reaction (PCR) from 18 patients with CRC, who had been treated with anti-EGFR antibody-based therapy (cetuximab) and subsequently acquired resistant cetuximab. HER2 gene copy number was analyzed using fluorescence in situ hybridization in tumor samples before and after acquisition of resistance to cetuximab-based therapy.ConclusionAnalysis of plasma ctDNA by digital PCR could be useful for detecting HER2 amplification in patients with CRC who were resistant to anti-EGFR antibody therapy.

HER-2 amplification in patients with adenocarcinoma of the esophagus and its implications for new adjuvant therapeutic strategies

HER-2 amplification in patients with adenocarcinoma of the esophagus and its implications for new adjuvant therapeutic strategies