HER2-negative Metastases Research Articles

HER2-low metastases of HER2-negative primary tumors: a single institution analysis of intertumoral and internodal heterogeneity in node-positive breast cancer.

HER2 status in breast cancer is an essential parameter in individual therapeutic decision-making and is routinely assessed in primary tumors in accordance with international recommendations. Reports of HER2 heterogeneity raise the question of basing treatment decisions on HER2 status in metastases, if present. We investigated the degree and clinical implications of HER2 heterogeneity in lymph node-positive breast cancer. Because of recent recognition of therapeutic opportunities in this group of tumors, we especially focused on cases involving low-level HER2 expression. The HER2 status of primary tumors and of corresponding lymph node metastases was determined in archived material at the protein and gene levels using the gene- protein assay and interpreted in accordance with 2018 ASCO/CAP criteria. HER2-low status was defined as protein expression levels 1+ or 2+ with negative amplification status. We analyzed a series of 43 cases of primary infiltrating breast cancer, each with at least two axillary nodes harboring macrometastases (>2 mm), in total 206 such nodes. In 7% of cases, we detected intertumoral HER2 heterogeneity. Three of nine HER2-positive primary tumors were associated with HER2-negative metastases. No cases with HER2-negative primary tumors had HER2-positive metastases, but 55% (6/11) of HER2 0 primary tumors had HER2 1+ and/or 2+ metastases, and 19% (3/16) HER2 1+ cases had exclusively HER2 0 metastases. All metastases in HER2 2+ cases showed HER2-low protein expression levels. Internodal HER2 heterogeneity at low protein expression levels (presence of HER2 0, HER2 1+, and/or HER2 2+ metastatic deposits within the same axilla) was seen in 40% (17/43) of cases. We found no statistically significant association between HER2 heterogeneity and other tumor-related parameters. Survival data indicated worse outcomes in the HER2-low group compared with the rest of the cohort. Our results indicate a substantial instability of HER2 protein expression, leading to considerable intertumoral and internodal HER2 heterogeneity in lymph node-positive breast carcinomas. This heterogeneity is particularly relevant in HER2-low tumors in which the corrective effects of HER2 gene copy number analysis definitionally is absent. Our findings suggest that determining HER2 status in metastatic lymph nodes may generate relevant information for therapeutic decision-making.

Clinical significance of HER2 and EGFR expression in colorectal cancer patients with ovarian metastasis

BackgroundEGFR and HER2 overexpression has been reported to play important roles in colorectal cancer (CRC) development and metastasis. Ovarian metastasis is rare yet is one of the most malignant metastases of CRC, but very few studies have focused on its biological features. This study aimed to investigate the expression of EGFR and HER2 in ovarian metastases of CRC and to reveal their clinical significance.MethodsThe expression of HER2 and EGFR in both primary tumours and ovarian metastases was analysed by immunohistochemistry (IHC) in 31 CRC patients with ovarian metastases as well as in the primary tumours of 26 CRC patients with non-ovarian metastases. The overall survival time was calculated with a Kaplan-Meier survival curve and compared with a log-rank test.ResultsHER2 positivity in primary tumours was significantly higher in patients with ovarian metastases than in those with non-ovarian metastases (54.5% vs. 36.4%, P < 0.05). The EGFR-positive rate in primary lesions was not significantly different between patients with ovarian metastases and those with non-ovarian metastases (63.6% vs. 58.3%, P > 0.05). HER2 expression was not correlated with age, primary tumour site, tumour differentiation, tumour diameter or vascular cancer embolus (P > 0.05). The positive rates of HER2 and EGFR in ovarian metastases were 44.8 and 69.0%, respectively. HER2 expression in ovarian metastases was correlated with peritoneal metastasis and bilateral ovarian metastasis (P < 0.05) but not with age, synchronous or metachronous ovarian metastases and the primary tumour site (P > 0.05). There was no significant correlation between EGFR expression and the clinicopathological features in ovarian metastases (P > 0.05). CRC patients with HER2-positive ovarian metastases showed a shortened overall survival time compared to that of CRC patients with HER2-negative metastases (17.0 ± 5.2 vs. 32.0 ± 8.3 months).ConclusionOur studies revealed that EGFR and HER2 are highly expressed in the primary tumours and metastases of CRC patients with ovarian metastases. HER2 positivity may be a negative prognostic predictor in patients with ovarian metastases.

Abstract P5-03-06: Clinical value of 89Zr-trastuzumab PET in HER2-positive breast cancer patients with a clinical dilemma

Abstract Background: Information on human epidermal growth factor receptor 2 (HER2) is essential for management of metastatic breast cancer (mBC). In patients suspected of HER2-positive mBC, standard work up may fail to clarify whole body HER2 status. We aimed to assess whether 89Zr-trastuzumab PET can support treatment decisions in patients posing this clinical dilemma. Methods: 89Zr-trastuzumab PET was performed as described earlier (Gaykema et al, Clin Cancer Res 2014) in patients in whom standard work up with bone scan, FDG PET, CT and if feasible a biopsy, failed to evaluate HER2 status of their disease. 89Zr-trastuzumab PET was defined positive, when at least a dominant part of the tumor load showed substantial tracer uptake (Gebhart et al, Ann Oncol 2015), when tumor tracer uptake in single lesions (except brain) was ≥ normal liver uptake or when brain metastases had a tracer uptake &amp;gt; background. Circulating tumor cell (CTC) analysis prior to tracer injectionwas performed using the CellSearch System (Janssen Diagnostics LLC) and CTC HER2 status was assessed immunofluorescently. Questionnaires about treatment decisions were completed before, directly after and ≥3 months after 89Zr-trastuzumab PET. Results: Twenty patients were enrolled: 8 with two primary cancers (HER2-positive and HER2-negative BC or BC and non-BC), 7 with metastases inaccessible for biopsy, 4 with prior HER2-positive and HER2-negative metastases, 1 with primary BC with equivocal HER2 status (average 4.23 HER2 gene copies/nucleus). 89Zr-trastuzumab PET was positive in 12 patients, negative in 7 and equivocal in one patient. In 15/20 patients 89Zr-trastuzumab PET supported treatment decision. The scan altered treatment of 8 patients, increased physicians' confidence without affecting treatment in 10, and improved physicians' understanding of disease in 18 patients. Ten patients had 1-99 CTCs, 6 with HER2 expression. There was no correlation between HER2 expression by CTCs and 89Zr-trastuzumab PET results or subsequent treatment decision. Conclusion: 89Zr-trastuzumab PET, but not CTC analysis, supports clinical decision making in BC patients in whom standard work up fails to evaluate HER2 status. (Funded by the Dutch A Sister's Hope). Citation Format: Schröder CP, Bensch F, Brouwers AH, Lub-de Hooge MN, de Jong JR, van der Vegt B, Sleijfer S, de Vries EG. Clinical value of 89Zr-trastuzumab PET in HER2-positive breast cancer patients with a clinical dilemma [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-03-06.

Genomic alterations in DNA repair and chromatin remodeling genes in estrogen receptor-positive metastatic breast cancer patients with exceptional responses to capecitabine.

We analyzed the genomic and phosphoproteomic profiles of breast cancer tissue obtained from six patients with estrogen receptor (ER)-positive, HER2-negative metastatic breast cancer who had highly durable (≥5 years) and, in some cases, ongoing clinical responses with capecitabine. Formalin-fixed, paraffin-embedded tissue samples from patients’ primary (n = 4) or metastatic (n = 2) breast cancers were utilized for targeted next-generation sequencing and reversed phase protein microarray. Two patients received capecitabine monotherapy. Four patients received capecitabine in combination with paclitaxel; three of these continued single-agent capecitabine after stopping paclitaxel. Capecitabine was discontinued for progressive disease after a mean of 66 months in four patients (range 54–86 months), and two patients remain on therapy, having received capecitabine for >91 months and >122 months, respectively. Three patients’ cancers (50%) had likely functional alterations in DNA repair and chromatin remodeling genes, while three other patients’ cancers had variants of unknown significance in these pathways. Mutations in PIK3CA, amplifications of FGFR1 or ZNF703, or phosphorylation of HER family receptors and their downstream proteins did not preclude exceptional responses to capecitabine. None of the patients’ tumors harbored TP53 or PTEN mutations. Four of the patients had breast cancer tissue available for PTEN immunohistochemistry, and all four patients’ cancers were positive for PTEN. These surprising findings in a group of phenotypically similar patients with ER-positive, endocrine therapy-pretreated, HER2-negative metastases, are supported by preclinical data showing that sensitivity to 5-fluorouracil is enhanced by deficiencies in chromatin remodeling and homologous recombination genes. Our findings suggest that mutations that inactivate homologous recombination and/or chromatin remodeling genes within ER-positive, HER2-negative breast cancers may predict for highly durable responses to capecitabine.

Abstract P4-01-17: Molecular imaging and quantification of HER-2 status in metastatic breast cancer by using 68Ga-ABY-025/PET-CT

Abstract Background: Molecular imaging, in particular, positron emission tomography (PET) provides unique possibility to non-invasively quantify the biomarkers. A small peptide, ABY-025, is targeting a unique epitope of the HER2-receptor and can be labeled with 111In or 68Ga. It is non-competitive with current antibody-targeted epitopes and is approximately 25 times smaller than an antibody and posses superior pharmacokinetics as imaging agent. We have earlier reported promising results of lesion visualization and determination of HER2 status by 111In-ABY-025/SPECT-CT in seven patients with metastatic breast cancer (MBC). As PET-CT provides superior possibilities for quantification and allows for imaging with shorter time frames, we now investigate 68Ga-ABY-025 in HER2-positive and HER2-negative MBC patients in a prospective study. The influence of the administered amount of ABY-025 on the discrimination between HER2-positive and HER2-negative metastases as well as detection rate and image contrast is investigated. The HER2 status changes will be followed at disease progression. We report here promising data on the first three patients. Patients and methods: The study considers twenty patients in two cohorts. Of the first 10 patients, 4 should have HER2-negative MBC and 6 patients HER2-positive disease. Metastases were localized by 18F-FDG/PET-CT prior HER2 imaging. Each patient (two HER2-positive and one HER-negative) underwent two subsequent examinations. First, 68Ga-ABY-025 PET/CT (ABY-025: 75±14 μg) was performed with dynamic acquisition during 0-45 minutes and static images after 1, 2 and 4 hours. The procedure was repeated after one week with a higher dose of 68Ga-ABY-025 (ABY-025: 445±10 μg) to identify the optimal dosage for the discrimination between HER2-positive and HER2-negative metastases. Blood levels of radioactivity, anti-ABY-025-antibodies, shed serum HER2 and toxicity markers were evaluated. Biopsies were taken to verify the HER2 status of the lesions. The second cohort of 10 patients (all with HER2-positive disease), will have their primary PET-CT with the optimal dose of 68Ga-ABY-025 and will, as the HER-positive from the first cohort, have a follow-up 68Ga-ABY-025 PET/CT after disease progression or, at latest, after 9 months. Results: The imaging agent was well tolerated by the patients without adverse events. The rapid blood clearance and normal tissue wash out allowed high contrast HER2 images within a few hours. The HER2 status was confirmed by histological analysis of biopsies. In one patient with HER2-negative primary tumor, imaging suggested a HER2-positive liver metastasis. The change of HER2 expression was verified with analysis of the corresponding biopsy. This finding resulted in the change of the treatment management. Preliminary validation suggests the preference of high dose ABY-025 in terms of image contrast and detection. The study is ongoing and more patients will be reported Conclusion: Preliminary results indicate strong potential of 68Ga-ABY-025 PET/CT for discriminating HER2-positive versus HER2-negative metastatic breast cancer, regardless of ongoing HER2-targeted antibody treatment. The method introduces rapid whole-body receptor mapping of primary tumor and metastases in a single examination. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-01-17.

Testing for Discordance at Metastatic Relapse: Does It Matter?

In the articles that accompany this editorial, two studies are reported that challenge the belief that a biopsy at the time of metastatic breast cancer relapse is not routinely required, because it provides no further information in regard to the optimal treatment of an individual patient’s tumor. Amir et al 1 report on a prospective trial assessing the clinical impact of tissue confirmation of metastatic disease in patients with breast cancer, and Niikura et al 2 describe rates of discordance and survival in a large single-institution cohort of patients with human epidermal growth factor 2 (HER2) positive primary breast cancer who had a metastatic tumor biopsy result available. Both of these studies are important for solidifying the results of numerous retrospective studies that have consistently demonstrated a discordant rate for either the estrogen receptor (ER) or HER2 receptor between the primary tumor and metastatic lesion. Although it is rational to attempt a biopsy for confirmation of metastatic disease for prognostic purposes, perhaps more contentious are the potential reasons behind, and the resultant clinical consequences of, an apparent discordant result. In the pragmatic and well-designed prospective cohort study by Amir et al, 1 patients presenting with evidence suggestive of metastatic disease or who were experiencing progression while receiving a palliative systemic treatment were enrolled. Strengths of the study were that the primary end point of the study was the proportion of patients in whom the biopsy result led to a change in systemic management, with secondary end points including patient-reported outcomes related to patient satisfaction. Neither of these important end points can be properly measured by means of retrospective study. The main conclusion of the study was the finding of discordance in either ER or HER2 in 16% and 10% of patients, respectively. In 14% of all patients enrolled, the biopsy result led to a reported change in management, with 88% of all participants stating they would recommend the biopsy procedure to other patients. In the retrospective study from the MD Anderson Cancer Centre (MDACC), 182 patients with HER2-positive primary breast cancers were identified, of whom 24% (n 43) were found to have an HER2-negative metastatic lesion on review. 2 Furthermore, the investigators demonstrated that the patients with a discordant HER2 result (HER2-positive primary disease but HER2-negative metastases) had worse survival than the patients with a concordant HER2 result (hazard ratio, 0.43; P .003). Strengths of this study were the relatively large cohort of HER2-positive primary breast cancers identified, the attempted central review of HER2 results (for those patients who were originally assessed at other institutions), and correlation of treatments and outcome between discordant and concordant subgroups. A discordant rate of approximately 25% in either ER or HER2 is well within the range seen in several recent larger retrospectives studies as well as one prospective study (BRITS [Breast Recurrence in Tissues Study]). 3-9 This range of discordance, between 20% and 30%, has been repeatedly demonstrated in these studies despite differences in methodology of assessment for the biomarkers between the primary and relapsed lesions, inclusion of both local and regional relapses with the distant tumors, and heterogeneity in patient populations. Despite