HER2 status in a population-derived breast cancer cohort: discordances during tumor progression

The changes of subtype markers between first and second primary breast cancers

BACKGROUND

Previous studies investigated the changes of subtype markers [estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2)] in several clinical settings, but not for second primary breast cancer (SPBC) after first primary breast cancer (FPBC).

METHODS

A total of 15,390 patients with SPBC were preliminarily selected from the Surveillance, Epidemiology, and End Results Program, and 3777 patients with complete information on three subtype markers in both FPBC and SPBC were included in the final analyses. The changes of subtype markers and their prognostic implications and potential influential factors were well investigated.

RESULTS

The overall change rates of ER, PR, and HER2 between FPBC and SPBC were 23.0% (867/3777), 35.0% (1322/3777), and 18.3% (691/3777), respectively. Gains of ER, PR, and HER2 after negative index markers were 48.7% (364/748), 37.9% (418/1103), and 11.5% (370/3211), while losses of markers after positive index markers were 16.6% (503/3029), 33.8%(904/2674), and 56.7%(321/566). Loss of ER was significantly associated with increased mortality (18.1% vs. 7.9%, p < 0.001), while gain of ER was significantly associated with decreased mortality (11.5% vs. 23.2%, p < 0.001). Similar results were observed for changes of PR status. However, loss of HER2 was significantly associated with decreased mortality (8.7% vs. 16.3%, p = 0.014), and no significant association was observed between the gain of HER2 and the prognosis of SPBC. Multivariate competing risk analyses showed similar results. HER2 status in FPBC, chemotherapy, and radiotherapy was significantly associated with changes of ER/PR (all p < 0.05), and no available therapies associated with HER2 change.

CONCLUSION

The changes of subtype markers are observed in a considerable proportion of patients and has statistically significant prognostic implications. Biopsies should be taken as a routine procedure for better therapy management.

Comprehensive Review of Metastatic Breast Carcinoma in Cytology Specimens

Breast carcinomas are known to metastasize to various organs of the human body. Fine needle aspiration cytology or exfoliative cytology often are the standard method for diagnosis at these metastatic sites due to ease of procurement of diagnostic material, accessibility, less complications, high sensitivity, and specificity of diagnosis and evaluation of biomarker status needed to guide future management. This comprehensive review article discusses in detail metastatic patterns, cytomorphology of metastatic breast cancer at different body sites, immunohistochemistry needed for diagnosis of breast carcinoma, sensitivity and specificity of diagnosis and breast biomarker assays in the cytology material.

The production of the first functional antibody mimetic in higher plants: the chloroplast makes the DARPin G3 for HER2 imaging in oncology

Background

Designed mimetic molecules are attractive tools in biopharmaceuticals and synthetic biology. They require mass and functional production for the assessment of upcoming challenges in the near future. The DARPin family is considered a mimetic pharmaceutical peptide group with high affinity binding to specific targets. DARPin G3 is designed to bind to the HER2 (human epidermal growth factor receptor 2) tyrosine kinase receptor. Overexpression of HER2 is common in some cancers, including breast cancer, and can be used as a prognostic and predictive tool for cancer. The chloroplasts are cost-effective alternatives, equal to, and sometimes better than, bacterial, yeast, or mammalian expression systems. This research examined the possibility of the production of the first antibody mimetic, DARPin G3, in tobacco chloroplasts for HER2 imaging in oncology.

Results

The chloroplast specific DARPin G3 expression cassette was constructed and transformed into N. tabacum chloroplasts. PCR and Southern blot analysis confirmed integration of transgenes as well as chloroplastic and cellular homoplasmy. The Western blot analysis and ELISA confirmed the production of DARPin G3 at the commercial scale and high dose with the rate of 20.2% in leaf TSP and 33.7% in chloroplast TSP. The functional analysis by ELISA confirmed the binding of IMAC purified chloroplast-made DARPin G3 to the extracellular domain of the HER2 receptor with highly effective picomolar affinities. The carcinoma cellular studies by flow cytometry and immunofluorescence microscopy confirmed the correct functioning by the specific binding of the chloroplast-made DARPin G3 to the HER2 receptor on the surface of HER2-positive cancer cell lines.

Conclusion

The efficient functional bioactive production of DARPin G3 in chloroplasts led us to introduce plant chloroplasts as the site of efficient production of the first antibody mimetic molecules. This report, as the first case of the cost-effective production of mimetic molecules, enables researchers in pharmaceuticals, synthetic biology, and bio-molecular engineering to develop tool boxes by producing new molecular substitutes for diverse purposes.

Application of a Novel 68Ga-HER2 Affibody PET/CT Imaging in Breast Cancer Patients

Background

Breast cancer is a heterogeneous disease, and the human epidermal growth factor receptor 2 (HER2) expression may vary considerably between primary and metastatic lesions, or even within a single lesion. Repeated biopsies cannot always be performed. In this feasibility trial, we assessed whether a novel ⁶⁸Ga-NOTA-MAL-MZHER2 (⁶⁸Ga-HER2) affibody PET/CT could determine the HER2 status of each lesion if there was a clinical need for it.

Methods

⁶⁸Ga-HER2 affibody PET/CT was performed in breast cancer patients if HER2 status remained unclear after standard examinations (including bone scan, ¹⁸F-FDG PET/CT, CT, and feasible biopsy). All available images for each patient were evaluated through an independent review of two committee-certified radiologists with nuclear medicine expertise. In case of discrepancy, adjudication by a third radiologist was performed as needed. All radiologists were blinded to the clinical information.

Results

Twenty-four patients were enrolled. ⁶⁸Ga-HER2 affibody PET/CT was requested by physicians due to the following reasons: 6 with multiple primary cancers, 13 with metastases not amenable to biopsy or repeated biopsy, 6 with inconsistent HER2 status between primary and metastatic lesions, and 4 with different HER2 status within different metastases. The final PET report revealed that the ⁶⁸Ga-HER2 affibody tumor uptake was considered positive in 16 patients, negative in 7 patients, and equivocal in one patient. The heterogeneity of ⁶⁸Ga-HER2 affibody uptake was observed, with a maximal 8.5-fold difference within one patient and a maximal 11-fold difference between patients. ⁶⁸Ga-HER2 affibody PET/CT demonstrated a high diagnostic accuracy in differentiating HER2-enriched breast cancer, with a sensitivity of 91.7% and a specificity of 84.6%, regardless of prior lines of anti-HER2 therapies.

Conclusion

⁶⁸Ga-HER2 affibody PET/CT imaging could provide valuable information on HER2 expression of each tumor in the body of patients, which may help in personalized clinical decision-making. Its value is now under systemic assessment.

Circulating tumor cell assay to non-invasively evaluate PD-L1 and other therapeutic targets in multiple cancers

Biomarker directed selection of targeted anti-neoplastic agents such as immune checkpoint inhibitors, small molecule inhibitors and monoclonal antibodies form an important aspect of cancer treatment. Immunohistochemistry (IHC) analysis of the tumor tissue is the method of choice to evaluate the presence of these biomarkers. However, a significant barrier to biomarker testing on tissue is the availability of an adequate amount of tissue and need for repetitive sampling due to tumor evolution. Also, tumor tissue testing is not immune to inter- and intra-tumor heterogeneity. We describe the analytical and clinical validation of a Circulating Tumor Cell (CTC) assay to accurately assess the presence of PD-L1 22C3 and PD-L1 28.8, ER, PR and HER2, from patients with solid tumors to guide the choice of suitable targeted therapies. Analytically, the test has high sensitivity, specificity, linearity and precision. Based on a blinded case control study, the clinical sensitivity and specificity for PD-L1 (22C3 and 28.8) was determined to be 90% and 100% respectively. The clinical sensitivity and specificity was 83% and 89% for ER; 80% and 94% for PR; 63% and 89% for HER2 (by ICC); and 100% and 92% for HER2 (by FISH), respectively. The performance characteristics of the test support its suitability and adaptability for routine clinical use.

Systematic review and meta-analysis of breast cancer brain metastasis and primary tumor receptor expression discordance

Background

Change in hormone receptor (estrogen [ER] and progesterone [PR]) and/or human epidermal growth factor receptor type 2 (HER2) status during the evolutionary course of metastatic breast cancer and the effect of tumor classification subtype switching remain understudied and underappreciated in brain metastasis patients.

Methods

Using preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines, a systematic review of series published prior to April 2020 obtained from the Medline database of biopsied or resected breast cancer brain metastasis (BCBM) was performed. Weighted random effects models were used to calculate pooled estimates.

Results

15 full-text articles were included with receptor expression analyses on 1373 patients who underwent biopsy or resection of at least one intracranial lesion to compare to the primary tumor. Primary tumor receptor expression immunophenotypes were 45.0% ER+, 41.0% ER−, 31.0% PR+, 51.0% PR−, 35% HER2+, and 47.0% HER2−. Corresponding BCBM immunophenotypes were 19.0% ER+, 31.0% ER−, 13.0% PR+, 40.0% PR−, 21.0% HER2+, and 26.0% HER2−. On primary/BCBM comparison, 540 patients (42.6%) exhibited discordance in any receptor with 17.0% (95% CI: 13.0%–23.0%) discordant on ER, 23.0% (95% CI: 18.0%–30.0%) discordant on PR, and 12.0% (95% CI: 8.0%–16.0%) discordant on HER2 status. The most common receptor conversions found in BCBM were ER loss 11.0% (95% CI: 8.0%–16.0%), PR loss 15.0% (95% CI: 11.0%–21.0%), and HER2 gain 9.0% (95% CI: 7.0%–11.0%).

Conclusions

BCBM exhibits significant receptor expression discordance in comparison to primary tumors in approximately 40% of patients. Classification patterns need to be analyzed to determine factors predictive of BCBM/primary tumor discordance. Overall, tumor subtype switching and its effect on clinical management remains underappreciated.

Efficacy of anti-HER2 therapy in metastatic breast cancer by discordance of HER2 expression between primary and metastatic breast cancer

PURPOSE

In stage IV breast cancer, the efficacy of human epidermal growth factor receptor 2 (HER2) targeted therapies in cases with discordance in HER2 expression between primary and metastatic site is not well known. We studied progression free (PFS) and overall survival (OS) by HER2 concordance when treating women with taxane-trastuzumab (± pertuzumab) in first or second line and trastuzumab-emtansine (T-DM1) or capecitabine-lapatinib in later lines.

PATIENTS AND METHODS

Retrospective monocentric study including all breast cancer patients receiving trastuzumab between January 2002 and September 2017 at the University Hospital in Leuven; we selected metastatic patients with an available HER2 status in primary and metastatic site. The Kaplan-Meier method was used for estimating PFS/OS and log-rank test for analyzing between group differences. A Cox model is used for testing difference between groups while correcting for Pertuzumab. Multivariable Cox regression is used to model overall survival as a function group, correcting for possible confounders.

RESULTS

We included 74 patients; 46 had an unchanged HER2 status (positive/positive), 9 lost HER2 (positive/negative), while 19 acquired HER2 amplification (negative/positive). 25 out of 28 cases with a discordant HER2 status were positive for ER and/or PgR in the primary site. HER2 positive/negative cases had a significantly lower PFS for taxane-trastuzumab-(pertuzumab) (PFS = 5.5 months), compared to HER2 positive/positive (PFS 9 months, p = 0.01) and HER2 negative/positive (PFS 14 months, p = 0.01) patients. PFS for later line T-DM1 (n = 30) was significantly higher for the HER2 positive/positive group (PFS 6.0 months) than for the discordant groups HER2 negative/positive (PFS 1.0 month, p = 0.04) and HER2 positive/negative (PFS 1.5 month, p = 0.01). After correcting for possible confounders, the HER2 positive/negative group had a significantly worse OS compared to HER2 positive/positive (HR 0.19, 95% CI 0.08-0.44) and negative/positive (HR 0.15, 95% 0.06-0.38).

CONCLUSION

Conversion of HER2 status was seen in 28 out of 74 cases and was mostly observed in hormone receptor-positive tumors. In contrast to patients with HER2 loss, patients with a positive conversion of HER2 status derived substantial benefit from first line treatment with taxane-trastuzumab-(pertuzumab). This study highlights the importance of re-biopsying the metastatic lesion and changing treatment according to the last HER2 result.

High expression of OSR1 as a predictive biomarker for poor prognosis and lymph node metastasis in breast cancer

PURPOSE

Oxidative stress-responsive kinase 1 (OSR1) plays a crucial role in regulating diverse cellular pathophysiologic functions, including ion homeostasis, development, differentiation, angiogenesis, invasive migration, and metastasis. Regardless, the clinical significance of OSR1 in breast cancer is scarce. The current study was conducted to evaluate the effect of OSR1 on the prognosis of patients with breast cancer with a long-term follow-up.

METHODS

OSR1 expression in formalin-fixed and paraffin-embedded tissue specimens was analyzed. These specimens were collected from 551 evaluable breast cancer cases by immunohistochemistry (IHC). OSR1 expression was dichotomized based on the H-score in IHC. The effects of OSR1 levels on the clinicopathological attributes and survival prediction in patients with breast cancer were explored.

RESULTS

Among 551 specimens, 183 (33.2%) exhibited high expression of OSR1 in tumor cells. High OSR1 levels were markedly correlated with histologic grade (P = 0.035), ER (P < 0.001) and PgR (P = 0.043) expression, lymph node involvement (P < 0.001), TNM stage (P < 0.001), and axillary surgery procedures (P = 0.003). Univariate analysis results indicate that patients with high OSR1 expression had significantly poor overall survival (P < 0.001), distant disease-free survival (P < 0.001), and breast cancer-specific survival (P < 0.001). Multivariable Cox regression analyses suggest that OSR1 expression was an independent predictive marker of poor prognosis and lymph node metastasis (HR 3.224, 95% CI 1.182-8.702, P = 0.023) in patients with breast cancer.

CONCLUSIONS

Our findings indicate that OSR1 is a significantly independent prognosis index for patients with breast cancer with respect to distant disease-free survival, overall survival, and breast cancer-specific survival. High OSR1 expression caused an increase in deaths specifically attributed to breast cancer and was related to increased lymph node metastasis. However, the precise cellular mechanisms for OSR1 in breast cancer require further research.

Discordant Marker Expression Between Invasive Breast Carcinoma and Corresponding Synchronous and Preceding DCIS

Ductal carcinoma in situ (DCIS) is considered a potential precursor of invasive breast carcinoma (IBC). Studies aiming to find markers involved in DCIS progression generally have compared characteristics of IBC lesions with those of adjacent synchronous DCIS lesions. The question remains whether synchronous DCIS and IBC comparisons are a good surrogate for primary DCIS and subsequent IBC. In this study, we compared both primary DCIS and synchronous DCIS with the associated IBC lesion, on the basis of immunohistochemical marker expression. Immunohistochemical analysis of ER, PR, HER2, p53, and cyclo-oxygenase 2 (COX-2) was performed for 143 primary DCIS and subsequent IBC lesions, including 81 IBC lesions with synchronous DCIS. Agreement between DCIS and IBC was assessed using kappa, and symmetry tests were performed to assess the pattern in marker conversion. The primary DCIS and subsequent IBC more often showed discordant marker expression than synchronous DCIS and IBC. Strikingly, 18 of 49 (36%) women with HER2-positive primary DCIS developed an HER2-negative IBC. Such a difference in HER2 expression was not observed when comparing synchronous DCIS and IBC. The frequency of discordant marker expression did not increase with longer time between primary DCIS and IBC. In conclusion, comparison of primary DCIS and subsequent IBC yields different results than a comparison of synchronous DCIS and IBC, in particular with regard to HER2 status. To gain more insight into the progression of DCIS to IBC, it is essential to focus on the relationship between primary DCIS and subsequent IBC, rather than comparing IBC with synchronous DCIS.

Liquid biopsy for the detection and management of surgically resectable tumors

BACKGROUND

Traditional biopsies have numerous limitations in the developing era of precision medicine, with cancer treatment that relies on biomarkers to guide therapy. Tumor heterogeneity raises the potential for sampling error with the use of traditional biopsy of the primary tumor. Moreover, tumors continuously evolve as new clones arise in the natural course of the disease and under the pressure of treatment. Since traditional biopsy is invasive, it is neither feasible nor practical to perform serial biopsies to guide treatment in real time.

PURPOSE

The current manuscript will review the most commonly used types of liquid biopsy and how these apply to surgical patients in terms of diagnosis, prediction of outcome, and guiding therapy.

CONCLUSIONS

Liquid biopsy has the potential to overcome many of the limitations of traditional biopsy as a highly tailored, minimally invasive, and cost-effective method to screen and monitor response to treatment. However, many challenges still need to be overcome before liquid biopsy becomes a reliable and widely available option.

Hormone receptor, human epidermal growth factor receptor-2, and Ki-67 status in primary breast cancer and corresponding recurrences or synchronous axillary lymph node metastases

The therapeutic strategy for breast cancer is determined by the surrogate subtype, which is defined by biomarkers, such as estrogen receptor (ER), progesterone receptor (PgR), human epidermal growth factor receptor-2 (HER2), and Ki-67. In previous reports, the rate of discordance in ER, PgR, and HER2 between primary breast cancer and recurrent lesions or synchronous axillary lymph node metastasis was 15-25, 25-40, and 5-25 or 7-50, 10-50, and 3-30%, respectively. Overall, hormone receptors tended to weaken during the metastatic process, while patterns of HER2 were not uniform. Regarding the Ki-67 labeling index, an increase in metastatic lesions compared with primary lesions was the dominant pattern, suggesting that aggressive subclones with high proliferative potential form metastases. The loss of expression of hormone receptor or an increase in the Ki-67 labeling index in metastasis seemed to be associated with a poor prognosis. However, most previous studies did not report the background characteristics of patients, or they included subjects with varied characteristics, including those on systemic therapy, and were based on relatively small populations; therefore, definitive conclusions could not be drawn. Future studies should explore how to select therapies according to the biomarkers in primary breast cancer and/or its metastasis.

Ancillary Tests in Breast Cytology: A Practical Guide

Utilization of fine-needle aspiration biopsy (FNAB) cytology for the diagnosis of diseases of the breast has been met with both excitement and uncertainty during the last couple of decades. Presently, FNAB for the diagnosis of primary and metastatic breast lesions is on the rise again. This is probably due to its fast turnaround time, cost efficiency, and minimal invasiveness, characteristics of this sampling modality which are particularly crucial for patients requiring frequent repeat biopsy in the setting of metastatic lesions. In this article, we will briefly review the main modern applications of FNAB of the breast when coupled with contemporary ancillary techniques. Such contemporary ancillary techniques range from classic immunocytochemistry (ICC) to the most modern molecular techniques, particularly next-generation sequencing. Coupled with contemporary ICC and molecular methods, FNAB of the breast can be used for several applications. The applications reviewed in this article include the primary diagnosis of a breast lesion, the identification of the breast as a primary source of a metastatic lesion, the evaluation of breast prognostic/predictive markers, and the tracking of tumor evolution. In our opinion, FNAB of the breast is an ideal sampling method, sharing many of the advantages of truly liquid and of tissue biopsies. Ultimately, we aim at demystifying the complexity of many of the challenges traditionally associated with the application of ancillary techniques to FNAB of the breast and provide insights into some of the most cutting-edge and clinically useful application scenarios.

Comparison of tumor‑targeting properties of directly and indirectly radioiodinated designed ankyrin repeat protein (DARPin) G3 variants for molecular imaging of HER2

Evaluation of human epidermal growth factor receptor 2 (HER2) expression levels in breast and gastroesophageal cancer is used for the stratification of patients for HER2‑targeting therapies. The use of radionuclide molecular imaging may facilitate such evaluation in a non‑invasive way. Designed ankyrin repeat proteins (DARPins) are engineered scaffold proteins with high potential as probes for radionuclide molecular imaging. DARPin G3 binds with high affinity to HER2 and may be used to visualize this important therapeutic target. Studies on other engineered scaffold proteins have demonstrated that selection of the optimal labeling approach improves the sensitivity and specificity of radionuclide imaging. The present study compared two methods of labeling G3, direct and indirect radioiodination, to select an approach providing the best imaging contrast. G3‑H6 was labeled with iodine‑124, iodine‑125 and iodine‑131 using a direct method. A novel construct bearing a C‑terminal cysteine, G3‑GGGC, was site‑specifically labeled using [125I]I‑iodo‑[(4‑hydroxyphenyl)ethyl]maleimide (HPEM). The two radiolabeled G3 variants preserved binding specificity and high affinity to HER2‑expressing cells. The specificity of tumor targeting in vivo was demonstrated. Biodistribution comparison of [131I]I‑G3‑H6 and [125I]I‑HPEM‑G3‑GGGC in mice, bearing HER2‑expressing SKOV3 xenografts, demonstrated an appreciable contribution of hepatobiliary excretion to the clearance of [125I]I‑HPEM‑G3‑GGGC and a decreased tumor uptake compared to [131I]I‑G3‑H6. The direct label provided higher tumor‑to‑blood and tumor‑to‑organ ratios compared with the indirect label at 4 h post‑injection. The feasibility of high contrast PET/CT imaging of HER2 expression in SKOV3 xenografts in mice using [124I]I‑G3‑H6 was demonstrated. In conclusion, direct radioiodination is the preferable approach for labeling DARPin G3 with iodine‑123 and iodine‑124 for clinical single photon emission computed tomography and positron emission tomography imaging.

Intra-tumor molecular heterogeneity in breast cancer: definitions of measures and association with distant recurrence-free survival

PURPOSE

The purpose of the study was to define quantitative measures of intra-tumor heterogeneity in breast cancer based on histopathology data gathered from multiple samples on individual patients and determine their association with distant recurrence-free survival (DRFS).

METHODS

We collected data from 971 invasive breast cancers, from 1st January 2000 to 23rd March 2014, that underwent repeat tumor sampling at our institution. We defined and calculated 31 measures of intra-tumor heterogeneity including ER, PR, and HER2 immunohistochemistry (IHC), proliferation, EGFR IHC, grade, and histology. For each heterogeneity measure, Cox proportional hazards models were used to determine whether patients with heterogeneous disease had different distant recurrence-free survival (DRFS) than those with homogeneous disease.

RESULTS

The presence of heterogeneity in ER percentage staining was prognostic of reduced DRFS with a hazard ratio of 4.26 (95% CI 2.22-8.18, p < 0.00002). It remained significant after controlling for the ER status itself (p < 0.00062) and for patients that had chemotherapy (p < 0.00032). Most of the heterogeneity measures did not show any association with DRFS despite the considerable sample size.

CONCLUSIONS

Intra-tumor heterogeneity of ER receptor status may be a predictor of patient DRFS. Histopathologic data from multiple tissue samples may offer a view of tumor heterogeneity and assess recurrence risk.

Comparative Evaluation of Radioiodine and Technetium-Labeled DARPin 9_29 for Radionuclide Molecular Imaging of HER2 Expression in Malignant Tumors

High expression of human epidermal growth factor receptor 2 (HER2) in breast and gastroesophageal carcinomas is a predictive biomarker for treatment using HER2-targeted therapeutics (antibodies trastuzumab and pertuzumab, antibody-drug conjugate trastuzumab DM1, and tyrosine kinase inhibitor lapatinib). Radionuclide molecular imaging of HER2 expression might permit stratification of patients for HER2-targeting therapies. In this study, we evaluated a new HER2-imaging probe based on the designed ankyrin repeat protein (DARPin) 9_29. DARPin 9_29 was labeled with iodine-125 by direct radioiodination and with [^99mTc]Tc(CO)₃ using the C-terminal hexahistidine tag. DARPin 9_29 preserved high specificity and affinity of binding to HER2-expressing cells after labeling. Uptake of [¹²⁵I]I-DARPin 9_29 and [^99mTc]Tc(CO)₃-DARPin 9_29 in HER2-positive SKOV-3 xenografts in mice at 6 h after injection was 3.4 ± 0.7 %ID/g and 2.9 ± 0.7 %ID/g, respectively. This was significantly (p < 0.00005) higher than the uptake of the same probes in HER2-negative Ramos lymphoma xenografts, 0.22 ± 0.09 %ID/g and 0.30 ± 0.05 %ID/g, respectively. Retention of [¹²⁵I]I-DARPin 9_29 in the lung, liver, spleen, and kidneys was appreciably lower compared with [^99mTc]Tc(CO)₃-DARPin 9_29, which resulted in significantly (p < 0.05) higher tumor-to-organ ratios. The biodistribution data were confirmed by SPECT/CT imaging. In conclusion, radioiodine is a preferable label for DARPin 9_29.

The dynamics of HER2 status in esophageal adenocarcinoma

Trastuzumab, a monoclonal antibody against HER2, has become standard of care for metastatic HER2-overexpressing esophagogastric adenocarcinoma and is currently investigated as (neo)adjuvant treatment option in HER2-positive esophagogastric adenocarcinoma. The HER2 status is commonly determined on archived material of the primary tumor. However, this status may change over the course of treatment or disease progression. The aim of this study was to assess the dynamics of HER2 status in esophageal adenocarcinoma (EAC) in patients with resectable and recurrent disease, and to determine the associations of these changes with clinical outcome. Discordance, defined as any change in HER2 status between matched biopsy and post-neoadjuvant chemoradiation therapy resection specimen (N = 170), or between matched resection specimen and recurrence of patients not eligible for curative treatment (N = 61), was determined using the standardized HER2 status scoring system. Clinically relevant positive discordance was defined as a change to HER2 positive status, as this would imply eligibility for HER2-targeted therapy. A difference in HER2 status between biopsy and resection specimen and resection specimen and metachronous recurrence was observed in 2.1% (n = 3) and 3.3% (n = 2) of the paired cases, respectively. Clinically relevant discordance was detected in 1.4% (n = 2) of the resectable patients and 1.6% (n = 1) of the patients with recurrent disease. Patients with HER2-positive status tumors before start of neoadjuvant treatment showed better overall survival, but not statistically significant. No association between HER2 status discordance and survival was found. Clinically relevant HER2 status discordance was observed and in order to prevent under-treatment of patients, the assessment of HER2 status in the metastatic setting should preferably be performed on the most recently developed lesions if the previous HER2 assessment on archival material of the primary tumor was negative.

Production of human single-chain fragment antibody (ScFv) against human epidermal growth factor receptor-2 (HER-2) by phage display technology

Breast cancer with more than 1.7 million diagnoses per year has been known as one of the most prevalent cancers among women worldwide. Despite the availability of advanced treatment options, cancer progression and metastasis is observed in 20% of patients. Human epidermal growth factor receptor-2 (HER-2) is considered as an important prognostic and diagnostic tumor marker for breast cancer. While HER-2 is expressed on the surface of normal cells, its overexpression occurs in 20-25% on breast cancer tumor cells. This type of tumor which is referred to as HER-2+ is the most aggressive type of breast cancer and shows more resistance to radiotherapy. Single-chain fragment antibodies (ScFvs) offer several advantages in comparison to conventional whole antibodies due to their small size. Particularly, ScFv fragments show improved diffusion and solid tumor penetration. In this study, a human ScFv antibody library was used to isolate anti-HER-2 ScFv antibodies through cell panning and mix antigen-cell panning strategies. Analysis of the binding activity and specificity of isolated ScFv antibodies against HER-2-expressing cell lines and recombinant HER-2 antigen indicated the higher efficiency of the cell panning strategy in isolation of ScFv antibody fragments.

Discordance in HER2 Status in Gastro-esophageal Adenocarcinomas: A Systematic Review and Meta-analysis

Trastuzumab combined with chemotherapy is standard of care for HER2 positive advanced gastro-esophageal cancers. The reported prevalence of HER2 discordance between primary tumors and corresponding metastases varies, hampering uniform patient selection for HER2 targeted therapy. This meta-analysis explores the influence of HER2 assessment methods on this discordance and investigates the prevalence of HER2 discordance in gastro-esophageal adenocarcinomas. PubMed, Embase and Cochrane databases were searched until January 2016. Differences in discordance rate between strict and broad(er) definitions of HER2 status were assessed using random-effect pair-wise meta-analysis. Random-effect single-arm meta-analyses were performed to assess HER2 discordance and the prevalence of positive and negative conversion. A significantly lower discordance rate in HER2 status between primary tumors and corresponding metastases was observed using a strict vs. broad definition of HER2 status (RR = 0.58, 95%CI 0.41-0.82), with a pooled discordance rate of 6.2% and 12.2%, respectively. Using the strict definition of HER2 assessment pooled overall discordance was 7% (95%CI 5-10%). The lowest discordance rates between primary tumors and corresponding metastasis are observed when using a strict method of HER2 positivity. Treatment outcomes of different studies will be better comparable if selection of eligible patients for HER2 targeted therapy is based on this strict definition.

Intra-image referencing for simplified assessment of HER2-expression in breast cancer metastases using the Affibody molecule ABY-025 with PET and SPECT

PURPOSE

In phase I/II-studies radiolabelled ABY-025 Affibody molecules identified human epidermal growth factor receptor 2 (HER2) expression in breast cancer metastases using PET and SPECT imaging. Here, we wanted to investigate the utility of a simple intra-image normalization using tumour-to-reference tissue-ratio (T/R) as a HER2 status discrimination strategy to overcome potential issues related to cross-calibration of scanning devices.

METHODS

Twenty-three women with pre-diagnosed HER2-positive/negative metastasized breast cancer were scanned with [¹¹¹In]-ABY-025 SPECT/CT (n = 7) or [⁶⁸Ga]-ABY-025 PET/CT (n = 16). Uptake was measured in all metastases and in normal spleen, lung, liver, muscle, and blood pool. Normal tissue uptake variation and T/R-ratios were established for various time points and for two different doses of injected peptide from a total of 94 whole-body image acquisitions. Immunohistochemistry (IHC) was used to verify HER2 expression in 28 biopsied metastases. T/R-ratios were compared to IHC findings to establish the best reference tissue for each modality and each imaging time-point. The impact of shed HER2 in serum was investigated.

RESULTS

Spleen was the best reference tissue across modalities, followed by blood pool and lung. Spleen-T/R was highly correlated to PET SUV in metastases after 2 h (r = 0.96, P < 0.001) and reached an accuracy of 100% for discriminating IHC HER2-positive and negative metastases at 4 h (PET) and 24 h (SPECT) after injection. In a single case, shed HER2 resulted in intense tracer retention in blood. In the remaining patients shed HER2 was elevated, but without significant impact on ABY-025 biodistribution.

CONCLUSION

T/R-ratios using spleen as reference tissue accurately quantify HER2 expression with radiolabelled ABY-025 imaging in breast cancer metastases with SPECT and PET. Tracer binding to shed HER2 in serum might affect quantification in the extreme case.

Cytologic assessment of estrogen receptor, progesterone receptor, and HER2 status in metastatic breast carcinoma

BACKGROUND

Discordance in the receptor status between primary breast carcinomas (PBC) and corresponding metastasis is well documented. Interrogation of the receptor status of metastatic breast carcinoma (MBC) in cytology material is common practice; however, its utility has not been thoroughly validated. We studied patients with MBC, and evaluated the concordance rates of estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2) between PBC surgical specimens and corresponding MBC cell blocks (CBs). We correlated the findings with clinicopathologic variables and with the fixation methods used.

METHODS

We searched for patients with MBC diagnosed on cytology from 2007 to 2009 and selected those with ER, PR and HER2 tested in both the PBC surgical specimens and the MBC CBs. We included CBs fixed in formalin and methanol based solution (CytoLyt®). All slides were reevaluated by cytopathologists. Clinical information was retrieved from the medical records.

RESULTS

We studied 65 patients with PBC and MBC paired specimens. The concordance rates between PBC and MBC were 78.5%, 58.5% and 96.9%, for ER, PR and HER2, respectively. When discordant, PR status switched from positive (PBC) to negative (MBC) in most cases (23/27). The PR concordance rate was 45.2% for CBs fixed in formalin and 70.6% for those fixed with CytoLyt® (p=0.047).

CONCLUSION

The ER, PR and HER2 concordance rates between the PBC and MBC CBs are similar to those reported in paired surgical specimens. PR status was the most prevalent discordance and was not accompanied by a switch in ER.

A FISH-based method for assessment of HER-2 amplification status in breast cancer circulating tumor cells following CellSearch isolation

Introduction

Amplification of the HER-2/neu (HER-2) proto-oncogene occurs in 10%–15% of primary breast cancer, leading to an activated HER-2 receptor, augmenting growth of cancer cells. Tumor classification is determined in primary tumor tissue and metastatic biopsies. However, malignant cells tend to alter their phenotype during disease progression. Circulating tumor cell (CTC) analysis may serve as an alternative to repeated biopsies. The Food and Drug Administration-approved CellSearch system allows determination of the HER-2 protein, but not of the HER-2 gene. The aim of this study was to optimize a fluorescence in situ hybridization (FISH)-based method to quantitatively determine HER-2 amplification in breast cancer CTCs following CellSearch-based isolation and verify the method in patient samples.

Methods

Using healthy donor blood spiked with human epidermal growth factor receptor 2 (HER-2)-positive breast cancer cell lines, SKBr-3 and BT-474, and a corresponding negative control (the HER-2-negative MCF-7 cell line), an in vitro CTC model system was designed. Following isolation in the CellSearch system, CTC samples were further enriched and fixed on microscope slides. Immunocytochemical staining with cytokeratin and 4′,6-diamidino-2′-phenylindole dihydrochloride identified CTCs under a fluorescence microscope. A FISH-based procedure was optimized by applying the HER2 IQFISH pharmDx assay for assessment of HER-2 amplification status in breast cancer CTCs.

Results

A method for defining the presence of HER-2 amplification in single breast cancer CTCs after CellSearch isolation was established using cell lines as positive and negative controls. The method was validated in blood from breast cancer patients showing that one out of six patients acquired CTC HER-2 amplification during treatment against metastatic disease.

Conclusion

HER-2 amplification status of CTCs can be determined following CellSearch isolation and further enrichment. FISH is superior to protein assessment of HER-2 status in predicting response to HER-2-targeted immunotherapy in breast cancer patients. This assay has the potential of identifying patients with a shift in HER-2 status who may benefit from treatment adjustments.

Evaluation of the first 44Sc-labeled Affibody molecule for imaging of HER2-expressing tumors

INTRODUCTION

Affibody molecules are small (58 amino acids) high-affinity proteins based on a tri-helix non-immunoglobulin scaffold. A clinical study has demonstrated that PET imaging using Affibody molecules labeled with ⁶⁸Ga (T_½=68min) can visualize metastases of breast cancer expressing human epidermal growth factor receptor type 2 (HER2) and provide discrimination between tumors with high and low expression level. This may help to identify breast cancer patients benefiting from HER2-targeting therapies. The best discrimination was at 4h post injection. Due to longer half-life, a positron-emitting radionuclide ⁴⁴Sc (T_½=4.04h) might be a preferable label for Affibody molecules for imaging at several hours after injection.

METHODS

A synthetic second-generation anti-HER2 Affibody molecule Z_HER2:2891 was labeled with ⁴⁴Sc via a DOTA-chelator conjugated to the N-terminal amino group. Binding specificity, affinity and cellular processing ⁴⁴Sc-DOTA-Z_HER2:2891 and ⁶⁸Ga-DOTA-Z_HER2:2891 were compared in vitro using HER2-expressing cells. Biodistribution and imaging properties of ⁴⁴Sc-DOTA-Z_HER2:2891 and ⁶⁸Ga-DOTA-Z_HER2:2891 were evaluated in Balb/c nude mice bearing HER2-expression xenografts.

RESULTS

The labeling yield of 98±2% and specific activity of 7.8GBq/μmol were obtained. The conjugate demonstrated specific binding to HER2-expressing SKOV3.ip cells in vitro and to SKOV3.ip xenografts in nude mice. The distribution of radioactivity at 3h post injection was similar for ⁴⁴Sc-DOTA-Z_HER2:2891 and ⁶⁸Ga-DOTA-Z_HER2:2891, but the blood clearance of the ⁴⁴Sc-labeled variant was slower and the tumor-to-blood ratio was reduced (15±2 for ⁴⁴Sc-DOTA-Z_HER2:2891 vs 46±9 for ⁶⁸Ga-DOTA-Z_HER2:2891). At 6h after injection of ⁴⁴Sc-DOTA-Z_HER2:2891 the tumor uptake was 8±2% IA/g and the tumor-to-blood ratio was 51±8. Imaging using small-animal PET/CT demonstrated that ⁴⁴Sc-DOTA-Z_HER2:2891 provides specific and high-contrast imaging of HER2-expressing xenografts.

CONCLUSION

The ⁴⁴Sc- DOTA-Z_HER2:2891 Affibody molecule is a promising probe for imaging of HER2-expression in malignant tumors.

Intratumor Heterogeneity in Breast Cancer

Intratumor heterogeneity is the main obstacle to effective cancer treatment and personalized medicine. Both genetic and epigenetic sources of intratumor heterogeneity are well recognized and several technologies have been developed for their characterization. With the technological advances in recent years, investigators are now elucidating intratumor heterogeneity at the single cell level and in situ. However, translating the accumulated knowledge about intratumor heterogeneity to clinical practice has been slow. We are certain that better understanding of the composition and evolution of tumors during disease progression and treatment will improve cancer diagnosis and the design of therapies. Here we review some of the most important considerations related to intratumor heterogeneity. We discuss both genetic and epigenetic sources of intratumor heterogeneity and review experimental approaches that are commonly used to quantify it. We also discuss the impact of intratumor heterogeneity on cancer diagnosis and treatment and share our perspectives on the future of this field.

Comparison of the HER2, estrogen and progesterone receptor expression profile of primary tumor, metastases and circulating tumor cells in metastatic breast cancer patients

Background

The expression of HER2, estrogen (ER) and progesterone (PR) receptor can change during the course of the disease in breast cancer (BC). Therefore, reassessment of these markers at the time of disease progression might help to optimize treatment decisions. In this context, characterization of circulating tumor cells (CTCs) could be of relevance since metastatic tissue may be difficult to obtain for repeated analysis. Here we compared HER2/ER/PR expression profiles of primary tumors, metastases and CTCs.

Methods

Ninety-six patients with metastatic BC from seven University BC Centers in Germany were enrolled in this study. Blood was obtained at the time of first diagnosis of metastatic disease or disease progression and analyzed for CTCs using the AdnaTest BreastCancer (QIAGEN Hannover GmbH, Germany) for the expression of EpCAM, MUC-1, HER2, ER and PR. HER2 expression on CTCs was additionally assessed by immunocytochemistry using the CellSearch® assay.

Results

The detection rate for CTCs using the AdnaTest was 43 % (36/84 patients) with the expression rates of 50 % for HER2 (18/36 patients), 19 % for ER (7/36 patients) and 8 % for PR (3/36 patients), respectively. Primary tumors and CTCs displayed a concordant HER2, ER and PR status in 59 % (p = 0.262), 39 % (p = 0.51) and 44 % (p = 0.62) of cases, respectively. For metastases and CTCs, the concordance values were 67 % for HER2 (p = 0.04), 43 % for ER (p = 0.16) and 46 % for PR (p = 0.6). Using the CellSearch® assay, the CTC-positivity rate was 53 % (42/79 patients) with HER2 expressed in 29 % (12/42) of the patients. No significant concordance (58 % and 53 %) was found when HER2 on CTCs was compared with HER2 on primary tumors (p = 0.24) and metastases (p = 0.34). Interestingly, primary tumors and metastases were highly concordant for HER2 (84 %, p = 1.13E-08), ER (90 %, p = 3.26E-10) and PR (83 %, p = 2.09E-09) and ER-and PR-positive metastases were significantly found to be of visceral origin (p = 0.03, p = 0.02).

Conclusion

Here we demonstrate that the molecular detection of HER2 overexpression in CTC is predictive of the HER2 status on metastases. Detailed analysis of ER and PR expression rates in tissue samples and CTCs may provide useful information for making treatment decisions.

Prognostic Impact of Discordance in Hormone Receptor Status Between Primary and Recurrent Sites in Patients With Recurrent Breast Cancer

INTRODUCTION

Recent retrospective studies have reported discordance rate of hormone receptor (HR) and human epidermal growth factor receptor 2 (HER2) statuses between primary and recurrent tumors and prognostic values of discordance. However, the results of these reports may possibly include analytical error.

PATIENTS AND METHODS

We analyzed 153 patients from whom pathological specimens of tumor tissues were available from both primary and recurrent sites. For all specimens, immunohistochemistry was performed for these statuses with a standardized method. Two experienced pathologists evaluated these specimens in a blinded fashion.

RESULTS

The discordance rates for estrogen receptor, progesterone receptor, and HER2 were 18%, 26%, and 7%, respectively. Subtype changes based on HR and HER2 status occurred in 21% of patients. Clinical outcome was significantly worse in the patients with the tumors that were primarily HR-positive (HR(+)) converted to HR-negative (HR(-)) at recurrent sites than in the patients with the tumors in which HR status did not change or converted from HR(-) to HR(+) (P = .001). Clinical outcome was also significantly worse in the patients with the primarily HR(+) tumor that converted to triple negative in the recurrence sites than in the patients with a constantly HR(+) tumor (P < .001). By the Cox multivariate analyses, loss of HR expression and conversion to triple negative at the recurrence sites were independent indicators of worse clinical outcome.

CONCLUSION

Discordance in HR and HER2 status often occurred between primary and recurrent breast cancer and had independent prognostic impact in the patients with recurrent breast cancer.

Meaningful interpretation of serum HER2 ECD levels requires clear patient clinical background, and serves several functions in the efficient management of breast cancer patients

BACKGROUND

This study was initiated to evaluate the clinical significant of HER2 extracellular domain (ECD) in the real-time management of breast cancer patients.

METHODS

Five-hundred forty-six eligible breast cancer patients were divided according to their clinical background. The correlation between ECD, tissue HER2, and clinical outcome of the patients were analyzed.

RESULTS

Receiver operating characteristic analysis revealed that ECD measured before receiving neoadjuvant therapy yielded the highest area under the curve (0.9185; P<0.0001), indicating that ECD and tissue HER2 levels are consistent in untreated tumor-bearing patients. At cut-off of 15.0ng/ml, the prognostic value of ECD was demonstrated using univariate (HR=1.664, P<0.0001) and multivariate (HR=1.547, P=0.011) Cox regression analysis. Kaplan-Meier survival curves revealed that patients with elevated ECD had shorter progression-free survival (PFS) (4.0 vs. 6.1months, P<0.0001). Elevated ECD was also an adverse predictor for PFS in response to anti-HER2 therapy (4.3 vs. 10.2months, P=0.0155). In contrast, ≥20%, decreased ECD was associated with longer PFS in patients who received anti-HER2 therapy (10.9 vs. 2.4months, P=0.0164) and overall (10.7 vs. 2.8months, P=0.0034).

CONCLUSIONS

A patient's clinical history can help determine whether ECD could provide added value for breast cancer management.

Comparison of Predictive Immunohistochemical Marker Expression of Primary Breast Cancer and Paired Distant Metastasis using Surgical Material: A Practice-Based Study

Parallel studies of primary breast carcinomas and corresponding distant metastases samples reveal considerable differences. Our aim was to highlight this issue from another perspective and provide further data based on 98 patient samples: 69 primary breast carcinoma and 85 distant metastases from bone, central nervous system (CNS) and lung (56 paired). Two independent series of immunohistochemical reactions with different antibodies for estrogen receptor (ER), progesterone receptor (PgR) and human epidermal growth factor receptor 2 (Her2), along with HER2 fluroscence in situ hybridization (FISH) were performed on tissue microarrays to classify breast carcinoma and distant metastases samples into Luminal A, Luminal B-proliferating, Luminal B-HER2+, HER2+ and triple negative (TNBC) surrogate breast cancer groups. Correlation and agreement between the two assessments of ER and PgR were fair-to-moderate, and almost perfect for HER2 and Ki67. There was 40% discordance concerning immunophenotype between breast carcinomas and distant metastases. Most common metastatic site of ER+ breast carcinoma was the skeletal system (59.2%), whereas that of TNBCs was the CNS (58.8%) and lungs (23.5%). Distant metastases in bones were mostly luminal (54.3%), in the CNS, Luminal B (53.2%), and in the lung, TNBC (37.5%). The change of drugable properties of primary breast cancers in the respective bone and CNS metastases suggests that characterization of the metastasis is necessary for appropriate treatment planning.

Intrinsic subtypes and genomic signatures of primary breast cancer and prognosis after systemic relapse

Molecular subtypes and gene expression signatures are widely used in early breast cancer but their role in metastatic disease is less explored. Two hundred-twenty patients diagnosed with primary breast cancer and subsequent relapse in Stockholm, Sweden between 1997 and 2006 were identified and their primary tumor was assessed for immunohistochemistry (IHC)- and PAM50-based subtypes, risk of recurrence (ROR-S) score, 21-gene and 70-gene signatures using research-based microarray expression profiles. Clinical and pathological data were retrospectively collected. Post-relapse survival within intrinsic subtypes and genomic signatures was investigated by Kaplan-Meier and Cox regression methods. ROR weighted for proliferation index (ROR-P) was explored and the prognostic contribution provided when combined to a clinical model estimated as change in LR- χ(2). IHC classified 27%, 24%, 36% and 13% of the tumors as luminal A, luminal B, HER2+ and triple negative, respectively. PAM50 categorized 22%, 24%, 26%, 22%, 6% of the tumors as luminal A, luminal B, HER2-enriched, basal-like and normal-like. Triple negative and basal tumors had a significantly shorter median post-relapse survival in comparison with luminal. Overall, neither IHC nor PAM50 subtypes, 21- and 70- gene profiles were prognostic in multivariable models. Low and medium ROR-S had a longer survival compared with the high-risk group (23 vs 10 months; p = 0.04). ROR-P independently correlated with post-relapse survival (p = 0.002) and provided the most significant prognostic information when added to a clinical model. ROR score from primary tumor represents an independent prognostic factor of post-relapse survival beyond classical clinical and pathological variables.

FGFR1 Amplification in Squamous Cell Carcinoma of the Lung with Correlation of Primary and Metastatic Tumor Status

BACKGROUND

The FGFR1 gene can be amplified in squamous cell carcinoma of the lung (SqCC). The aim of this study was to compare FGFR1 status with stage and matched primaries with metastases.

METHODS

Cases with FGFR1 fluorescence in situ hybridization (FISH) testing performed from 2000 to 2013 were evaluated for amplification status and clinicopathologic features.

RESULTS

Of the 336 cases tested by FGFR1 FISH, 52 (15%) were positive for amplification. Eight (13%) of 60 N0 cases and eight (17%) of 46 N1 or N2 cases were amplified, with no statistically significant difference. Of the 24 cases with matched primary and metastatic tumors, 22 (92%) were synchronous and one (4%) had discordant amplification.

CONCLUSIONS

Frequency of FGFR1 amplification is similar in SqCC with and without lymph node metastases, but status in metastatic sites may be discordant from the primary in a small subset of cases, which may affect the decision to perform testing of metastatic SqCCs.

Measuring HER2-Receptor Expression In Metastatic Breast Cancer Using [68Ga]ABY-025 Affibody PET/CT

Purpose: Positron Emission Tomography (PET) imaging of HER2 expression could potentially be used to select patients for HER2-targed therapy, predict response based on uptake and be used for monitoring. In this phase I/II study the HER2-binding Affibody molecule ABY-025 was labeled with ⁶⁸Ga-gallium ([⁶⁸Ga]ABY-025) for PET to study effect of peptide mass, test-retest variability and correlation of quantified uptake in tumors to histopathology.

Experimental design: Sixteen women with known metastatic breast cancer and on-going treatment were included and underwent FDG PET/CT to identify viable metastases. After iv injection of 212±46 MBq [⁶⁸Ga]ABY-025 whole-body PET was performed at 1, 2 and 4 h. In the first 10 patients (6 with HER2-positive and 4 with HER2-negative primary tumors), [⁶⁸Ga]ABY-025 PET/CT with two different doses of injected peptide was performed one week apart. In the last six patients (5 HER2-positive and 1 HER2-negative primary tumors), repeated [⁶⁸Ga]ABY-025 PET were performed one week apart as a test-retest of uptake in individual lesions. Biopsies from 16 metastases in 12 patients were collected for verification of HER2 expression by immunohistochemistry and in-situ hybridization.

Results: Imaging 4h after injection with high peptide content discriminated HER2-positive metastases best (p<0.01). PET SUV correlated with biopsy HER2-scores (r=0.91, p<0.001). Uptake was five times higher in HER2-positive than in HER2-negative lesions with no overlap (p=0.005). The test-retest intra-class correlation was r=0.996. [⁶⁸Ga]ABY-025 PET correctly identified conversion and mixed expression of HER2 and targeted treatment was changed in 3 of the 16 patients.

Conclusion: [⁶⁸Ga]ABY-025 PET accurately quantifies whole-body HER2-receptor status in metastatic breast cancer.

Evaluation of targeted therapies in advanced breast cancer: the need for large-scale molecular screening and transformative clinical trial designs

Breast cancer (BC) has been classified into four intrinsic subtypes through seminal studies employing gene expression profiling analysis of primary tumours, namely the luminal A and B subtypes, the human epidermal growth factor receptor 2-like subtype and the basal-like subtype. More recently, the emergence of high-throughput genomic sequencing techniques, such as next-generation or massive parallel sequencing has expanded our understanding of the complex genomic landscapes of BC, with marked intertumour heterogeneity seen among different patients. In addition, increasing evidence indicates intratumour heterogeneity, with molecular differences observed within one patient, both spatially and longitudinally. These phenomena have an impact on the clinical development of molecularly targeted agents, with the classical paradigm of population-based clinical trials being no longer efficient. In the era of genomically driven oncology, three complementary tools can accelerate the clinical development of targeted agents for advanced BC as follows: (i) the implementation of molecular profiling of metastatic tumour lesions, as exemplified by the AURORA (Aiming to Understand the Molecular Aberrations in Metastatic Breast Cancer) programme; (ii) serial assessments of circulating tumour DNA, allowing a more thorough molecular interrogation of metastatic tumour burden; and (iii) new innovative clinical trial designs able to address the challenges of the increasing molecular fragmentation of BC.

Progesterone Receptor Status and Clinical Outcome in Breast Cancer Patients with Estrogen Receptor-Positive Locoregional Recurrence

Aims and background

The aim of this retrospective multicenter study was to evaluate the impact of progesterone receptor (PgR) loss on locoregional recurrence in patients with estrogen receptor (ER)-positive primary breast cancer and ER-positive locoregional recurrence.

Patients and Methods

Eight Italian oncology centers collected data from consecutive patients with ER-positive breast cancer and a subsequent ER-positive locoregional recurrence.

Results

Data were available for 265 patients diagnosed with breast cancer between 1990 and 2009. Median metastasis-free survival was 111 months in patients with PgR-positive primary tumors and locoregional recurrence (PgRpos), 38 months in patients with PgR-negative primary tumors and locoregional recurrence (PgRneg), and 63 months in patients with PgR-positive primary tumors and PgR-negative locoregional recurrence (PgRloss). In multivariate analysis, PgR status was independently associated with metastasis-free survival, with a hazard ratio of 2.84 (95% CI 1.34-6.00) for PgRneg compared with PgRpos, and 2.93 (95% CI: 1.51-5.70) for PgRloss compared with PgRpos.

Conclusions

PgR absence was found to be a negative prognostic factor in breast cancer patients with ER-positive locoregional recurrence. Thus, PgR status could be a biological marker in ER-positive recurrent breast cancer.

Changes in glycoprotein expression between primary breast tumour and synchronous lymph node metastases or asynchronous distant metastases

Background

Breast cancer is a very heterogeneous disease and some patients are cured by the surgical removal of the primary tumour whilst other patients suffer from metastasis and spreading of the disease, despite adjuvant therapy. A number of prognostic and treatment predictive factors have been identified such as tumour size, oestrogen (ER) and progesterone (PgR) receptor status, human epidermal growth factor receptor type 2 (HER2) status, histological grade, Ki67 and age. Lymph node involvement is also assessed during surgery to determine if the tumour has spread which requires dissection of the axilla and adjuvant treatment. The prognostic and treatment predictive factors assessing the nature of the tumour are all routinely based on the status of the primary tumour.

Results

We have analysed a unique tumour set of fourteen primary breast cancer tumours with matched synchronous axillary lymph node metastases and a set of nine primary tumours with, later developed, matched distant metastases from different sites in the body. We used a pairwise tumour analysis (from the same individual) since the difference between the same tumour-type in different patients was greater. Glycopeptide capture was used in this study to selectively isolate and quantify N-linked glycopeptides from tumours mixtures and the captured glycopeptides were subjected to label-free quantitative tandem mass spectrometry analysis. Differentially expressed proteins between primary tumours and matched lymph node metastasis and distant metastasis were identified. Two of the top hits, ATPIF1 and tubulin β-chain were validated by immunohistochemistry to be differentially regulated.

Conclusions

We show that the expression of a large number of glycosylated proteins change between primary tumours and matched lymph node metastases and distant metastases, confirming that cancer cells undergo a molecular transformation during the spread to a secondary site. The proteins are part of important pathways such as cell adhesion, migration pathways and immune response giving insight into molecular changes needed for the tumour to spread. The large difference between primary tumours and lymph node and distant metastases also suggest that treatment should be based on the phenotype of the lymph node and distant metastases.

Electronic supplementary material

The online version of this article (doi:10.1186/s12014-015-9084-7) contains supplementary material, which is available to authorized users.

HER2 discordance between paired primary gastric cancer and metastasis: a meta-analysis

BACKGROUND

A number of studies have examined human epidermal growth factor receptor 2 (HER2) status in primary gastric cancer (GC) and associated metastasis, some showed their great concordance in HER2 expression, but others demonstrated notable discordance. There is still little consensus on HER2 discordance, therefore, a systematic review and meta-analysis was conducted to assess the status on HER2 discordance between primary GC and its paired metastasis.

METHODS

PubMed, EMBASE, ASCO and The Cochrane Library were searched for studies that explored the concordance between primary tumor and metastasis in patients with GC up to 10 March, 2014. Data of discordance of HER2 between primary GC and corresponding metastasis were extracted from the publications and random-effects models were used to estimate pooled discordance proportions.

RESULTS

Eighteen articles including 1,867 patients were included for the meta-analysis in accordance with the selection criteria. Pooled discordance proportions were 7% [95% confidence interval (CI): 5-10%] for HER2 status. Pooled proportions of tumors shifting from positive to negative and from negative to positive were 17% (95% CI: 7-29%) and 4% (95% CI: 2-6%) respectively. No publication bias was found in the meta-analysis.

CONCLUSIONS

The discordance of HER2 status is not rare in primary and metastatic GC through our meta-analysis. Prospective studies are needed to testify the clinical significance of the discordance of HER2 status.

Quantitative HER2 and p95HER2 levels in primary breast cancers and matched brain metastases

BACKGROUND

Patients with advanced breast cancer positive for human epidermal growth factor receptor 2 (HER2) are at high risk for brain metastasis (BM). The prevalence and significance of expression of HER2 and its truncated form p95HER2 (p95) in BM is unknown.

METHODS

Seventy-five pairs of formalin-fixed paraffin-embedded samples from matched primary breast cancers (PBCs) and BM were assayed for quantitative p95 and HER2-total (H2T) protein expression using the p95 VeraTag and HERmark assays, respectively.

RESULTS

There was a net increase in p95 and H2T expression in BM relative to the matched PBC (median 1.5-fold, P = .0007 and 2.1-fold, P < .0001, respectively). Cases with H2T-positive tumors were more likely to have the largest (≥5-fold) increase in p95 (odds ratio = 6.3, P = .018). P95 positivity in PBC correlated with progression-free survival (hazard ratio [HR] = 2.2, P = .013), trended with shorter time to BM (HR = 1.8, P = .070), and correlated with overall survival (HR = 2.1, P = .042). P95 positivity in BM correlated with time to BM (HR = 2.0, P = .016) but did not correlate with overall survival from the time of BM diagnosis (HR = 1.2, P = .61).

CONCLUSIONS

This is the first study of quantitative p95 and HER2 expression in matched PBC and BM. BM of breast cancer shows significant increases in expression of both biomarkers compared with matched PBC. These data provide a rationale for future correlative studies on p95 and HER2 levels in BM.

Biopsy confirmation of metastatic sites in breast cancer patients: clinical impact and future perspectives

Determination of hormone receptor (estrogen receptor and progesterone receptor) and human epidermal growth factor receptor 2 status in the primary tumor is clinically relevant to define breast cancer subtypes, clinical outcome, and the choice of therapy. Retrospective and prospective studies suggest that there is substantial discordance in receptor status between primary and recurrent breast cancer. Despite this evidence and current recommendations, the acquisition of tissue from metastatic deposits is not routine practice. As a consequence, therapeutic decisions for treatment in the metastatic setting are based on the features of the primary tumor. Reasons for this attitude include the invasiveness of the procedure and the unreliable outcome of biopsy, in particular for biopsies of lesions at complex visceral sites. Improvements in interventional radiology techniques mean that most metastatic sites are now accessible by minimally invasive methods, including surgery. In our opinion, since biopsies are diagnostic and changes in biological features between the primary and secondary tumors can occur, the routine biopsy of metastatic disease needs to be performed. In this review, we discuss the rationale for biopsy of suspected breast cancer metastases, review issues and caveats surrounding discordance of biomarker status between primary and metastatic tumors, and provide insights for deciding when to perform biopsy of suspected metastases and which one (s) to biopsy. We also speculate on the future translational implications for biopsy of suspected metastatic lesions in the context of clinical trials and the establishment of bio-banks of biopsy material taken from metastatic sites. We believe that such bio-banks will be important for exploring mechanisms of metastasis. In the future, advances in targeted therapy will depend on the availability of metastatic tissue.

Biomarkers in Patients with Metastatic Breast Cancer and the PRAEGNANT Study Network

Progress has been made in the treatment of metastatic breast cancer in recent decades, but very few therapies use patient or tumor-specific characteristics to tailor individualized treatment. More than ten years after the publication of the reference human genome sequence, analysis methods have improved enormously, fostering the hope that biomarkers can be used to individualize therapies and offer precise treatment based on tumor and patient characteristics. Biomarkers at every level of the system (genetics, epigenetics, gene expression, micro-RNA, proteomics and others) can be used for this. This has led to changes in clinical study designs, with drug developments often only focusing on small or very small subgroups of patients and tumors. The screening and registration of patients and their molecular tumor data has therefore become very important for the successful completion of clinical studies. This new form of medicine presents particular challenges for patients and physicians. Even in this new age of genome-wide analysis, the focus should still be on the patients' quality of life. This review summarizes recent developments and describes how the PRAEGNANT study network manages the aforementioned medical challenges and changes to create a professional infrastructure for patients and physicians.

HER2-directed therapy: current treatment options for HER2-positive breast cancer

Over the past decade, the management of HER2-positive breast cancer has evolved dramatically. In addition to advances in screening, genetic testing, imaging, surgical and radiation techniques, innovations in medical therapy including widespread use of HER2-directed therapy in early and advanced breast cancer have revolutionized breast cancer care and changed the natural history of HER2-positive breast cancer. A substantial number of HER2-targeted agents are being developed including monoclonal antibodies, small molecule inhibitors, and antibody drug conjugates. Trastuzumab is the prototype HER2-directed therapy that was introduced in the late 1990s for the management of metastatic breast cancer and later showed efficacy in early stage disease. Despite the practice changing impact of trastuzumab and improvement in outcomes of women with HER2-positive breast cancer resistance to trrastuzumab is a major clinical issue, occurring in both early stage and advanced disease, and new treatment strategies are clearly required. Combining HER2-targeted agents and dual HER2 blockade has been successful in early and advanced breast cancer. Furthermore, selected delivery of potent chemotherapeutic agent coupled with HER2 inhibition promises new treatment options. This review is focused on current HER2-directed treatments for women with HER2-positive breast cancer including monoclonal antibodies, small molecule inhibitors, and antibody drug conjugates.

Systemic treatment of HER2+ metastatic breast cancer: clinical conundrums and future perspectives

Improvements in the treatment of metastatic HER2-positive breast cancer constitute one of the great advances in breast cancer medicine of the last generation. From being a highly aggressive fatal condition, the use of anti-HER2-targeted therapies, in particular trastuzumab, has led to significant improvements in disease outcomes. There are reports of increasing numbers of patients alive and well more than 5 years from diagnosis of metastatic disease. Nevertheless, there remain many complex and clinically difficult scenarios where there is little in the way of randomized evidence or published guidelines to guide decision making. As a companion piece to our review of HER2-targeted therapies in the metastatic setting, we decided to focus on a series of clinical scenarios that fell outside of the standard trial-based settings and where opinions and guidance from experienced clinicians and experts in the field would be considered useful to help develop safe and effective treatment strategies. The following eight cases were put forward by our panel of experts, voted on by their peers to select the most relevant and interesting cases, and the discussions worked on by teams of two followed by review and commentary by another team of two.

Pragmatic issues in biomarker evaluation for targeted therapies in cancer

Predictive biomarkers are becoming increasingly important tools in drug development and clinical research. The importance of using both guidelines for specimen acquisition and analytical methods for biomarker measurements that are standardized has become recognized widely as an important issue, which must be addressed in order to provide high-quality, validated assays. Herein, we review the major challenges in biomarker validation processes, including pre-analytical (sample-related), analytical, and post-analytical (data-related) aspects of assay development. Recommendations for improving biomarker assay development and method validation are proposed to facilitate the use of predictive biomarkers in clinical trials and the practice of oncology.

Breast cancer during follow-up and progression - A population based cohort on new cancers and changed biology

BACKGROUND

Emerging data indicate an important role for biopsies of clinically/radiologically defined breast cancer 'recurrences'. The present study investigates tumour related events (relapses, other malignancies, benign conditions) after a primary breast cancer diagnosis.

PATIENTS AND METHODS

The cohort includes 2102 women, representing all patients, with primary invasive breast cancer during 2000-2011 in the county of Värmland, Sweden. A comparative analysis of oestrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2) and proliferation (Ki67) between the primary tumour and the relapse was performed and related to outcome.

RESULTS

With a mean follow-up time of 4.8 years, 1060 out of 2102 patients have had a biopsy taken after the initial breast cancer diagnosis demonstrating 177 recurrences, 93 other malignancies (colorectal, lung, skin), 40 cancer in situ (skin, breast) and 857 benign lesions. Approximately 70% (177 out of 245) of all cases of relapsed breast cancer underwent a biopsy during this time period. For patients with recurrences, ER (n=127), PR (n=101), HER2 (n=73) and Ki67 (n=55) status in both primary tumour and the corresponding relapse were determined. The discordance of receptor status was 14.2%, 39.6%, 9.6% and 36.3%, respectively. Loss of ER or PR in the relapse resulted in a significant increased risk of death (hazard ratio (HR) 3.62; 95% confidence interval (CI), 1.65-7.94) and (HR 2.34; 95% CI, 1.01-5.47) compared with patients with stable ER or PR positive tumours. The proportion of patients losing ER was bigger in the group treated with endocrine therapy alone or in combination with chemotherapy, 16.7% and 13.3%, respectively, compared with the group treated with chemotherapy alone or that which received no treatment 4.3% and 7.7%, respectively.

CONCLUSION

Discordance of biomarkers between the primary tumour and the corresponding relapse was seen in 10-40% of the patients, adjuvant therapies seem to drive clonal selections. Patients with tumours losing ER or PR during progression have worse survival compared with patients with retained receptor expression.

Discordances in ER, PR and HER2 receptors between primary and recurrent/metastatic lesions and their impact on survival in breast cancer patients

The aim of this study was to evaluate the frequency and prognostic impact of changes in the estrogen (ER), progesterone (PR) and human epidermal growth factor receptor 2 (HER2) status between primary and recurrent/metastatic lesions (RML). We investigated 133 breast cancer patients for ER, PR and HER2 status of primary and RML and their follow-up records. Among 133 patients with RML, discordance rate for ER, PR, and HER2 was 18.8, 33.8, and 6.8%, respectively. ER, PR and HER2 discordance were observed in 20.0, 38.1 and 6.7% of the patients with distant metastasis, and in 14.3, 17.9 and 7.1% of the patients with locoregional recurrence. The mean time between the primary diagnosis and last contact or death was 57 (range 22-78) months and between the recurrence biopsy and last contact or death was 17 (range 1-33) months. Among 133 patients with RML, the ER-discordant cases and ER-loss cases experienced a worse overall survival (OS) (p=0.001 and p=0.016, respectively) and post-recurrence survival (PRS) (p=0.001 and p=0.018, respectively), compared with the respective concordant cases. The HER2-discordant patients and HER2-loss patients had a poorer OS (p=0.008 and p=0.001, respectively) and PRS (p=0.004 and p=0.000, respectively) than the respective concordant cases. Among 105 patients with distant metastasis, ER discordance, ER loss, HER2 discordance and HER2 loss, compared with the respective concordant cases, resulted in a worse OS and PRS (p<0.05 for all). Our findings show an evident change in ER, PR and HER2 between breast primary tumors and relapsing tumors. The unstable status for ER or HER2 in breast cancer seems to be clinically significant and to correlate with a worse prognosis.

Optimal sequencing of anti-HER2 therapy throughout the continuum of HER2-positive breast cancer: evidence and clinical considerations

With the advent of the monoclonal antibody trastuzumab over 2 decades ago for breast cancer therapy, the outcome of patients with human epidermal growth factor receptor (HER) 2-positive disease has improved dramatically. Based on its substantial efficacy and good tolerability, trastuzumab has become the therapeutic gold standard for early as well as advanced breast cancer. Nevertheless, despite adjuvant trastuzumab, patients do experience recurrence and require further anti-HER2-targeted therapy. Next to the small molecule tyrosine kinase inhibitor lapatinib, which was the first approved therapy option after trastuzumab failure, several new anti-HER2 agents are currently already available for clinical use [i.e. pertuzumab, T-DM1 (trastuzumab emtansine)] or are still being evaluated (e.g. afatinib, neratinib). Recent evidence from neoadjuvant as well as metastatic therapy suggests that dual blockade may be superior to single-agent HER2 blockade. While the number of available or potential therapies has increased considerably, no additional predictive biomarkers beyond HER2 have been validated for the use of the different anti-HER2 therapies. Moreover, novel therapeutic concepts such as the antibody-drug conjugate T-DM1 warrant excellent determination methodology for HER2 and suggest re-evaluation of tumor biology upon first metastasis. The clinical challenge remains to optimally choose, utilize, and sequence anti-HER2 therapy in early as well as metastatic breast cancer. This article will provide evidence-based guidance for sequencing anti-HER2 therapy throughout the continuum of breast cancer therapy.