Mutations of HER2 gene in HER2-positive metastatic breast cancer

2006 ◽  
Vol 24 (18_suppl) ◽  
pp. 13118-13118 ◽  
Author(s):  
T. Prempree ◽  
C. Wongpaksa
Keyword(s):  
Breast Cancer ◽  
Gene Mutations ◽  
Metastatic Breast ◽  
Her2 Status ◽  
Trastuzumab Resistance ◽  
Her2 Gene ◽  
Her2 Positive ◽  
Primary Tumors ◽  
Trastuzumab Therapy ◽  
One Year

13118 Background: HER2 status of Breast Cancer has been assessed by IHC and FISH and used for therapeutic decision with a high degree of success. However, there were numbers of HER2-positive MBC who finally failed the Trastuzumab treatment after initial good response. Mechanisms of intrinsic and acquired Trastuzumab resistance are not yet known. Our Objective is to identify factor or factors responsible for Trastuzumab resistance. Methods: DNA extraction and Sequencing of HER2 gene were performed on primary tumors of HER2-positive 14 MBC patients undergoing Trastuzumab therapy. Re-biopsy were done on new metstatic sites of those cases discovered to have Trastuzumab resistance. Results: Of 14 MBC cases whose tumors showing positive IHC and FISH, there were no mutation found in their HER2 gene, exons 18,19, 20 and 21. However, 3 of 14 cases of MBC undergoing continuous Trastuzumab therapy with excellent response for more than one year, developed the resistance. All three cases had new metstatic sites biopsied, and showed D880N and E837Y mutations in the exon 21 of their HER2 genes. All three cases showed no response to trastuzumab therapy. Conclusions: 1) HER2-positive MBC tumors did not have any HER2 gene mutations in them. 2) Mutations arised in their HER2 gene, exon 21 may be responsible for the intrinsic and acquired Trastuzumab resistance. Additional work in this area is needed to further substantiate our findings. No significant financial relationships to disclose.

scholarly journals Loss of HER2 Positivity after Trastuzumab in HER2-Positive Gastric Cancer: Is Change in HER2 Status Significantly Frequent?

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Yu Ishimine ◽  
Akira Goto ◽  
Yoshito Watanabe ◽  
Hidetaka Yajima ◽  
Suguru Nakagaki ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Gastric Cancer ◽  
Residual Tumor ◽  
Her2 Status ◽  
Resected Specimen ◽  
Her2 Positive ◽  
Curative Intent ◽  
Course Of Disease ◽  
Trastuzumab Therapy ◽  
Her2 Positivity

Trastuzumab has recently been introduced as a treatment for HER2-positive metastatic and/or unresectable gastric cancer (MUGC); however, compared with breast cancer, some issues concerning HER2 and trastuzumab therapy for gastric cancer remain unclear. A 74-year-old woman received trastuzumab-containing chemotherapy for HER2-positive MUGC. She had a marked response to 8 months of chemotherapy, and gastrectomy and hepatic metastasectomy with curative intent were performed. The resected specimen showed complete loss of HER2 positivity in the residual tumor. For MUGC, a change in HER2 status during the course of the disease with or without chemotherapy has rarely been reported. However, in breast cancer, a significant frequency of change in HER2 status during the course of disease has been reported, and reevaluation of HER2 positivity in metastatic/recurrent sites is recommended. The choice of trastuzumab for MUGC is currently based on the HER2 status of the primary tumor at the time of initial diagnosis, without reassessment of HER2 status during the course of disease and/or in metastatic/recurrent sites, on the assumption that HER2 status is stable. However, our case casts doubt on the stability of HER2 in gastric cancer.

scholarly journals Prospective Study Evaluating the Impact of Tissue Confirmation of Metastatic Disease in Patients With Breast Cancer

2012 ◽  
Vol 30 (6) ◽  
pp. 587-592 ◽  
Author(s):  
Eitan Amir ◽  
Naomi Miller ◽  
William Geddie ◽  
Orit Freedman ◽  
Farrah Kassam ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Prospective Study ◽  
Treatment Plan ◽  
Growth Factor Receptor ◽  
Metastatic Breast ◽  
Her2 Status ◽  
Primary Tumors ◽  
Receptor Status ◽  
Metastatic Recurrence ◽  
The Impact

Purpose Decisions about treatment for women with metastatic breast cancer are usually based on the estrogen (ER), progesterone (PgR), and human epidermal growth factor receptor 2 (HER2) status of the primary tumor. Retrospective data suggest that discordance between primary and metastatic lesions leads to detrimental outcome. This prospective study investigated receptor status of primary tumors and metastases in the same patient and assessed the impact of discordance on patient management and survival. Patients and Methods Biopsies of suspected metastases were analyzed for ER, PgR, and HER2. Primary tumors and metastases were analyzed using similar methodology. The treating oncologist indicated a treatment plan before and after biopsy to determine whether the result influenced management. Patients were followed up for progression or death. Results Of 121 women undergoing biopsy, 80% could be analyzed for receptor status. Discordance in ER, PgR, and HER2 between the primary and the metastasis was 16%, 40%, and 10%, respectively. Biopsy led to a reported change of management in 14% of women (95% CI, 8.4% to 21.5%). Fine-needle aspiration and biopsy of bone led to reduced ability to analyze receptors. After a median follow-up of 12 months, there were no trends for an association between receptor discordance and either time to treatment failure or overall survival. Conclusion Biopsy of metastases is technically feasible. Clinicians alter immediate management in one of seven patients on the basis of results of the biopsy, and discordance is not then associated with detrimental effects on outcome. Tissue confirmation should be considered in women with breast cancer and suspected metastatic recurrence.

scholarly journals Somatic Mutations in HER2 and Implications for Current Treatment Paradigms in HER2-Positive Breast Cancer

2020 ◽  
Vol 2020 ◽  
pp. 1-13 ◽  
Author(s):  
Maria Gaibar ◽  
Laura Beltrán ◽  
Alicia Romero-Lorca ◽  
Ana Fernández-Santander ◽  
Apolonia Novillo
Keyword(s):  
Breast Cancer ◽  
Somatic Mutations ◽  
Tyrosine Kinase Domain ◽  
Her2 Overexpression ◽  
Breast Cancer Patients ◽  
Trastuzumab Resistance ◽  
Her2 Gene ◽  
Her2 Positive ◽  
Her2 Positive Breast Cancer ◽  
Positive Breast Cancer

In one of every four or five cases of breast cancer, the human epidermal growth factor receptor-2 (HER2) gene is overexpressed. These carcinomas are known as HER2-positive. HER2 overexpression is linked to an aggressive phenotype and a lower rate of disease-free and overall survival. Drugs such as trastuzumab, pertuzumab, lapatinib, neratinib, and the more recent afatinib target the deregulation of HER2 expression. Some authors have attributed somatic mutations in HER2, a role in resistance to anti-HER2 therapy as differential regulation of HER2 has been observed among patients. Recently, studies in metastatic ER + tumors suggest that some HER2 mutations emerge as a mechanism of acquired resistance to endocrine therapy. In an effort to identify possible biomarkers of the efficacy of anti-HER2 therapy, we here review the known single-nucleotide polymorphisms (SNPs) of the HER2 gene found in HER2-positive breast cancer patients and their relationship with clinical outcomes. Information was recompiled on 11 somatic HER2 SNPs. Seven polymorphisms are located in the tyrosine kinase domain region of the gene contrasting with the low number of mutations found in extracellular and transmembrane areas. HER2-positive patients carrying S310F, S310Y, R678Q, D769H, or I767M mutations seem good candidates for anti-HER2 therapy as they show favorable outcomes and a good response to current pharmacological treatments. Carrying the L755S or D769Y mutation could also confer benefits when receiving neratinib or afatinib. By contrast, patients with mutations L755S, V842I, K753I, or D769Y do not seem to benefit from trastuzumab. Resistance to lapatinib has been reported in patients with L755S, V842I, and K753I. These data suggest that exploring HER2 SNPs in each patient could help individualize anti-HER2 therapies. Advances in our understanding of the genetics of the HER2 gene and its relations with the efficacy of anti-HER2 treatments are needed to improve the outcomes of patients with this aggressive breast cancer.

Differential survival following trastuzumab treatment based on quantitative HER2 expression and HER2:HER2 dimerization in a clinic-based cohort of patients with metastatic breast cancer

2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 1025-1025 ◽  
Author(s):  
M. Toi ◽  
J. Sperinde ◽  
W. Huang ◽  
S. Saji ◽  
S. Ohno ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Metastatic Breast Cancer ◽  
Metastatic Breast ◽  
Cox Proportional Hazards ◽  
Her2 Expression ◽  
Her2 Gene ◽  
Her2 Positive ◽  
Differential Survival ◽  
Term Survival ◽  
Trastuzumab Treatment

1025 Background: Women with metastatic breast cancer (MBC) that overexpress HER2 experience improved overall survival (OS) when treated with trastuzumab. Immunohistochemistry (IHC) for HER2 protein expression and fluorescence in situ hybridization (FISH) for HER2 gene amplification are the preferred methods of determining HER2 positivity. However, not all HER2 positive patients respond equally well to trastuzumab. We describe the identification of subgroups of HER2+ patients with distinct clinical outcomes based on their quantitative levels of HER2 expression and HER2:HER2 dimerization. Methods: 75 patients with MBC drawn from six oncology clinics in Japan were assayed for HER2 expression and HER2:HER2 dimerization using FFPE specimens by the eTag assay, a proximity-based assay designed to detect and quantify protein-protein dimers. All patients had MBC, were treated with at least one chemotherapy (CT) regimen prior to receiving trastuzumab, and had FFPE specimens available for testing. 33% had at least 3 metastatic sites. 88% were selected for treatment based on IHC and 12% based on FISH. 16% were treated with trastuzumab alone and 84% with trastuzumab plus CT. Median clinical follow-up was 26 months. Cox proportional hazards and Kaplan-Meier (KM) analyses were performed. Results: The most significant variables associated with OS were the presence of brain metastases and the total number of metastases. In the overall population, correcting for the confounding influence of number of metastases, KM analyses demonstrated that patients with higher HER2 expression survived significantly longer than patients with lower HER2 expression (HR for death = 0.36, p = 0.0036). This relationship was even more significant for HER2:HER2 dimers (HR = 0.29, p = 0.0003). Conclusions: In a clinic-based population of Japanese women with MBC treated with heterogeneous prior and concomitant (with trastuzumab) CT regimens, the quantitative levels of HER2 expression and HER2:HER2 dimerization identified subsets of patients within a population of pre-selected HER2+ patients with different probabilities of long-term survival following trastuzumab treatment. No significant financial relationships to disclose.

HER2 status testing by immunohistochemical and fFluorescence in situ hybridization in China

2009 ◽  
Vol 27 (15_suppl) ◽  
pp. e22233-e22233
Author(s):  
W. Tao ◽  
J. Zefei ◽  
Z. Xuan ◽  
L. Xiaobing ◽  
Z. Shaohua ◽  
...  
Keyword(s):  
Breast Cancer ◽  
In Situ Hybridization ◽  
Her2 Status ◽  
Central Laboratory ◽  
Her2 Gene ◽  
Her2 Positive ◽  
Clinical Prognosis ◽  
Her2 Testing ◽  
Regional Laboratory

e22233 Background: HER2 gene overexpression is associated with aggressive breast cancer and poor clinical prognosis. Humanized anti-HER2 monoclonal antibody trastuzumab, which is targeted HER2 protein has showed to improve overall survival in patients with HER2-positive breast cancer in both the metastatic and adjuvant settings. There are some differences in HER2 positive rate among difference reports in China. This study tested HER2 status by immunohistochemistry(IHC) and fluorescence in situ hybridization (FISH) and compared HER2 testing at central and regional laboratories in China. Methods: Assessment of HER2 status was performed by FISH using the HercepTeast kit at central laboratory and by IHC using commercial available anti-HER2 probe in formalin-fixed and paraffin-embedded tissue section of 280 breast cancer samples. IHC HER2 testing was performed on 149 samples in the central laboratory. IHC HER2 testing was performed on 80 samples at both central laboratory and regional laboratory. Results: 280 samples were tested 373 times testing by IHC and FISH. The results were showed in table 1 . 80 samples was tested by IHC at central and regional laboratory and testing results of 36.4% samples were accordant (K=0.038). 94.1% IHC3+ at central laboratory were HER2 FISH positive and 83.3% IHC 3+ at regional laboratory were HER2 FISH positive. 86.7% IHC 2+ at central laboratory were HER2 FISH positive and 62.7% IHC 2+ at regional laboratory were HER2 FISH positive. 17 samples were observed HER2 FISH positive in the 27 IHC 0/1+ tested at regional laboratoty. So good correlation was obsearved between FISH HER2 status and IHC results from central laboratory but not from regional laboratory. Conclusions: This study emphasized the important of accurate HER2 testing. HER2 FISH test should be performed for the IHC 2+ samples. Even HER2 FISH test maybe performed for IHC 0/1 sample according to clinical characteristics in China in order to make the patients have targeted therapy chance. [Table: see text] No significant financial relationships to disclose.

Quantitative HER2 measurement and PI3K mutation profile in matched primary and metastatic breast cancer tissues.

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. 614-614
Author(s):  
Weidong Huang ◽  
Jonathan F. Lara ◽  
Richard Michaelson ◽  
Xiu Sun ◽  
Pierfranco Conte ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Metastatic Breast Cancer ◽  
Catalytic Domain ◽  
Pik3ca Mutation ◽  
Metastatic Breast ◽  
Her2 Status ◽  
Her2 Positive ◽  
Pik3ca Mutations ◽  
Meta Analyses ◽  
Negative Conversion

614 Background: HER2 status of primary breast cancer (PBC) is routinely used to determine systemic treatment for metastatic breast cancer (MBC) patients. Discordance rates of HER2 status between PBC and MBC range from 5.5% to 29% based on published meta-analyses. The clinical benefit of re-assessing HER2 in MBC tissues remains controversial. In this study, we measured quantitative HER2 expression in matched PBC and MBC tissues and correlated changes of HER2 with mutations in the catalytic domain of PI3 kinase(PIK3CA). Methods: Total HER2 protein expression (H2T) was quantified by the HERmark assay in 41 matched PBC and MBC formalin-fixed, paraffin-embedded specimens. PIK3CA mutation status in exons 9 (E545K and E542K) and 20 (H1047R) was determined using a validated pyrosequencing assay. Results: MBC samples included 5 lymph node, 13 viscera, 6 brain, and 17 soft tissue lesions (N=41). 27 (66%) cases showed higher H2T in MBC than in matched PBC; and 14 (34%) cases had higher H2T in PBC than in matched MBC, indicating an overall increase of H2T in matched MBC lesions (fold change 0.25-17.57; p=0.005, paired Wilcoxon rank sum test). HER2 positive conversion (HERmark negative/equivocal in PBC, but positive in matched MBC) was found in 6 (15%) cases, while HER2 negative conversion (HERmark positive in PBC, but negative/equivocal in matched MBC) was seen in 2 (5%) cases. HER2 status was unchanged in 33 (80%) cases. PIK3CA mutations were detected in 13 (32%) of PBC and 19 (46%) of MBC samples. Among the HER2 positive conversion cases, PIK3CA mutation was identified in 50% (3/6) PBC and 67% (4/6) MBC, compared to 0% (0/2, PBC or MBC) in the HER2 negative conversion cases. Among cases with unchanged HER2 status, PIK3CA mutation was observed in 30% (10/33) PBC and 42% (14/33) MBC. Conclusions: Quantitative HER2 assessment revealed a 20% discordance in HER2 status between matched PBC and MBC tissues, with more frequent conversion from low HER2 in PBC to high HER2 in MBC. PIK3CA mutation was observed more frequently in patients who converted from HER2 negative PBC to HER2 positive MBC. These results suggest that re-assessment of biomarkers in MBC tissues may better inform the selection of therapeutic options for patients with MBC.

Quantification of intratumoral heterogeneity of HER2 status in breast cancer.

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. 1036-1036
Author(s):  
Rie Horii ◽  
Masaaki Matsuura ◽  
Hiro Nitta ◽  
Yoshinori Ito ◽  
Shinji Ohno ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Tumor Cells ◽  
Intratumoral Heterogeneity ◽  
Gene Copy ◽  
Her2 Status ◽  
Her2 Gene ◽  
Her2 Positive ◽  
Her2 Positive Breast Cancer ◽  
Protein Status ◽  
Positive Breast Cancer

1036 Background: Intratumoral heterogeneity (ITH) occurs as a consequence of epigenetic aberrations in tumor cells with genetic diversity. HER2 ITH can be classified into genetic (a mixture of tumor cells with and without HER2 gene amplification) and epigenetic ITH (a mixture of HER2 gene-amplified tumor cells with and without HER2 protein overexpression). However, the both effects of genetic and epigenetic ITH on HER2-targeted therapy have not been clearly demonstrated. In order to implement ITH as a referenced factor for treatment selection, the ITH quantification is necessary. Gene-protein assay (GPA), in which immunohistochemistry and dual in situ hybridization are simultaneously performed on a single slide, allows bright-field analyses of both gene and protein status. We aimed to quantify HER2 ITH by the combination of gene and protein status and clarify its clinical significance. Methods: Fifty three patients with HER2-positive breast cancer, who underwent neoadjuvant trastuzumab with chemotherapy, were examined. Five representative microscopic images were captured from a GPA slide of a pre-therapeutic biopsy material. All evaluable tumor cells in the images were scored according to the HER2 status determined by the combination of gene copy number and protein expression (Table). We investigated the relationship between the HER2 scores and pathological complete response (pCR) to the neoadjuvant treatment by the logistic analysis. Results: The average of HER2 scores, indicating the degree of the HER2 status, varied from 2.21 to 5.98. It was significantly related to pCR (Estimate: 1.21, Std. error: 0.46, RR: 3.34, P=0.009, 95%CI: 1.35-8.25). The standard deviation of HER2 scores, indicating the degree of the HER2 ITH, varied from 0.13 to 1.37. It was significantly related to pCR (Estimate: -2.09, Std. error: 0.83, RR: 0.12, P=0.012, 95%CI: 0.02-0.63). Conclusions: HER2 ITH, quantified by GPA, is a predictive factor for the therapeutic effect to trastuzumab-based treatment in HER2-positive breast cancer. [Table: see text]

A phase Ib, first-in-human, dose escalation and expansion study of XMT-1522, a novel antibody-drug conjugate (ADC) directed against HER2, in patients with advanced breast cancer and other advanced tumors expressing HER2.

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. TPS2606-TPS2606 ◽  
Author(s):  
Howard A. Burris ◽  
Minal A. Barve ◽  
Erika Paige Hamilton ◽  
Aditya Bardia ◽  
Hatem Hussein Soliman ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Gastric Cancer ◽  
Advanced Breast Cancer ◽  
Dose Escalation ◽  
Metastatic Breast ◽  
Advanced Breast ◽  
Her2 Status ◽  
Her2 Positive ◽  
Post Dose ◽  
Human Dose

TPS2606 Background: XMT-1522 is an ADC consisting of a novel human IgG1 anti-HER2 monoclonal antibody conjugated to an auristatin-based cytotoxic payload (AF-HPA). An average of 12 AF-HPA molecules is conjugated to each antibody via a biodegradable polymer. In pre-clinical xenograft experiments XMT-1522 achieved complete, durable tumor regressions in models of HER2-positive and HER2 1+/2+ breast cancer, HER2 2+/3+ NSCLC, and HER2-positive and HER2 1+ gastric cancer. Methods: This study (NCT02952729) is comprised of two parts: a dose escalation segment (DES) and an expansion segment (EXP). The primary objectives of the DES are determination of the maximum tolerated dose and recommended Phase 2 dose (RP2D) and assessment of safety and tolerability. The DES will enroll patients with advanced or metastatic breast cancer who have progressed following standard therapies and have HER2 protein at least 1+ by IHC. XMT-1522 will be administered intravenously every 3 weeks. DES uses a 3+3 design. Post-dose assessments include LVEF measurement at the end of cycles 1, 3, then every 3 cycles, ophthalmologic exams at the end of cycles 1, 2, then every 2 cycles, and re-staging CT scans every 2 cycles. Pharmacokinetics of antibody, AF-HPA payload and an AF-HPA metabolite will be measured. Two patients have completed dose level 1 without DLT. The EXP segment will open at the RP2D and will further assess safety and tolerability of XMT-1522 and assess efficacy in selected patient populations. EXP will enroll 4 cohorts (N = 20 each). Cohort 1: HER2 1+/2+ advanced breast cancer with 2-3 prior chemotherapy regimens Cohort 2: HER2-positive advanced breast cancer with prior pertuzumab and ado-trastuzumab emtansine (T-DM1) Cohort 3: HER2-positive advanced gastric cancer with prior trastuzumab Cohort 4: HER2 2+/3+ NSCLC with at least 1 prior platinum regimen The protocol requires archival tumor tissue for central confirmation of HER2 status, alternative HER2 measurements, and targeted gene expression and sequencing studies. Tumor biopsies will be requested at the time of progression from patients who responded to XMT-1522. Clinical trial information: NCT02952729.

Sign in / Sign up

Export Citation Format

Share Document