Clinical significance of assessing Her2/neu expression in gastric cancer with dual tumor tissue paraffin blocks. Hum Pathol. 2015;46:850-857. [PMID: 25863425 DOI: 10.1016/j.humpath.2015.02.011]

Pilot study of HER2 targeted 64 Cu-DOTA-tagged PET imaging in gastric cancer patients

OBJECTIVE

Human epidermal growth factor receptor 2 (HER2) is an important biomarker for targeted gastric cancer (GC) immunotherapy. However, heterogeneous HER2 overexpression in GC, loss of HER2 expression during therapy, and inability to non-invasively identify HER2 overexpressing tumors impede effective targeting therapies. Improved HER2-specific functional imaging can address these challenges. Trastuzumab is a HER2-directed mAb to treat HER2 overexpressing cancers. The 64 Cu-DOTA-trastuzumab radiotracer is used to detect HER2+ metastatic breast cancer. We aimed to develop 64 Cu-DOTA-trastuzumab PET-CT to detect and characterize tumor uptake in HER2+ or - GC patients.

METHODS

We conducted a single-arm phase II pilot study exploring the feasibility of 64 Cu-DOTA-trastuzumab for PET imaging of HER2 overexpressing GC compared to HER2 non-expressing tumors. Eight patients with biopsy-confirmed gastric adenocarcinoma were included. Immunohistochemistry was used to evaluate primary tumor biopsies for HER2 overexpression. Patients were injected with 45 mg of cold trastuzumab followed by 5 mg of 64 Cu-DOTA-trastuzumab. PET-CT scans were performed 24-48 h post radiotracer injection and compared to standard staging CT scans.

RESULTS

We observed limited toxicity following 64 Cu-DOTA-trastuzumab injections. While there was uptake of the radiotracer in portions of HER2+ lesions, there was no statistically significant distinction between tumor and background by standardized uptake value analysis.

CONCLUSION

Despite the potential of 64 Cu-DOTA-trastuzumab PET imaging of HER2+ metastatic breast cancer, a 5 mg dose of this radiotracer injected 24-48 h before imaging was insufficient to identify HER2+ GC. These results inform future GC imaging studies to optimize biomarker-targeted therapies based on dosage and timing for more clinically relevant imaging.

Clinical Significance of Dual-Block Elastic Stain Evaluating Visceral Pleural Invasion in Peripheral Non-Small Cell Lung Cancer

Visceral pleural invasion (VPI) is a critical component in the staging of peripheral non-small cell lung carcinoma (NSCLC). We aim to investigate whether dual-block elastic stain increases visceral pleural invasion positivity compared with single-block elastic stain. We further analyze the potential predictors of visceral pleural invasion. 8419 peripheral NSCLC patients (including 6008 patients with tumor size≤3 cm in stage I) were divided into a cohort using one paraffin block (single-block group, n = 5184) and a cohort using dual paraffin blocks (dual-block group, n = 3235) for elastic stain. The VPI-positive rate demonstrated by the dual-block elastic stains group was significantly higher than that of the single-block elastic stain group (17.7% (573/3235) versus 9.1% (474/5184), respectively, P < .001). The presence of visceral pleural invasion in T1 (≤3 cm) patients detected by single- and dual-block elastic stain was 6.3% (235/3730) and 12.0% (273/2278), respectively (P < .001). 5.7% of T1 patients (stage IA) were additionally upstaged to T2a (stage IB) by dual-block elastic stain. However, the incidence of visceral pleural invasion in pT2a patients showed no significant difference between the single-block group and the dual-block group (16.8% vs. 17.1%, P = .916). Lymphovascular invasion, lymph node metastasis, dedifferentiated carcinomas, the presence of spread through airspaces (STAS) and a poorly differentiated adenocarcinomatous growth pattern could be significant predictors of visceral pleural invasion (P < .001). Our results indicate that using dual-block elastic stain identifies more visceral pleural invasion positive T1 NSCLC patients who are upstaged to T2a, and who could benefit from optimal management post-operatively. The application of dual-block elastic stain is an efficient and practical method to detect visceral pleural invasion status.

Comparison of 22C3-PD-L1 Expression Between Paired Tumor Paraffin Blocks of Surgical Resection Specimens of Nonsmall Cell Lung Cancer

In this study, our aim was to evaluate the discordance of programmed cell death ligand 1 (PD-L1) expression between 2 paired paraffin blocks from surgical nonsmall cell lung cancer (NSCLC) specimens, thus providing recommendations for choosing paraffin blocks for PD-L1 immunohistochemistry detection. A total of 460 paired paraffin blocks of surgical NSCLC specimens were analyzed using the 22C3-PD-L1 assay. PD-L1 expression between 2 paired paraffin blocks was calculated using 3 classification schemes, tumor proportion score (TPS)-based 3-level classification and TPS-based binary classification using TPS ≥1% or TPS ≥50% as the cutoff. Clinicopathological characteristics were analyzed for cases with discordant PD-L1 expression. PD-L1 expression in 2 paired paraffin blocks of surgical NSCLC specimens was highly correlated from a single tumor ( R2 =0.89) in the overall trend. The overall discordance rates were 10.9%, 7.4%, and 3.5% respectively when using TPS-based 3-level classification or binary classification. No statistical differences were observed in PD-L1 expression discordance rates when patients were stratified by age, sex, smoking status, histologic types, TNM stage, or years of paraffin blocks ( P >0.05). The presence of a solid histologic pattern was associated with a higher PD-L1 expression discordance rate in adenocarcinomas ( P <0.05). Twenty-five cases with discordant PD-L1 expression were divided into 2 categories: spatial heterogeneity without recognizable morphology difference (76%) and spatial heterogeneity with significantly different morphology (24%). The discordance rate in TPS scores was much higher in cases with different morphology than those without different morphology. One representative paraffin block containing adequate neoplastic tissue may be adequate to determine PD-L1 expression in most of the surgical specimens of NSCLC. In cases that harbored different morphology in different paraffin blocks, the dual-block immunohistochemistry assessment method is recommended due to the intratumoral heterogeneity.

Dual block HER2 assessment increased HER2 immunohistochemistry positive rate in resected specimens of gastric cancer: a prospective multicenter clinical trial from China

Background

Former single center studies indicated that HER2 assessment with two primary tumor blocks (dual block HER2 assessment) could be an efficient and practical approach to overcome the adverse impact of heterogeneity and acquire a HER2 positive rate in gastric cancer (GC). This multicenter prospective clinical trial (NCT 02843412) was launched to verify its value and generality.

Methods

A total of 3806 participants with primary GCs have been enrolled from 8 hospitals in China. Two primary tumor blocks were selected and recorded as block 1 and block 2 after histological evaluation. An HER2 (4B5) rabbit monoclonal antibody was used for the immunohistochemistry (IHC) analysis.

Results

In total patients, HER2 IHC positive (3+) rate with dual block assessment (9.4%) was higher than that with single block assessment (block 1: 7.8%, block 2: 7.8%) (P < 0.001). Compared with single-block assessment, dual-block assessment increased the positive rate by approximate 20%. Similarly, HER2 equivocal (2+) rate was increased in dual block assessment (25.8%), which was higher than that in single block assessment (block 1: 20.3%, block 2: 20.9%) (P < 0.001). Conversely, dual block assessment demonstrated a lower HER2 negative (0/1+) rate (64.8%) than single block assessment (block1: 71.9%, block 2: 71.3%) (P < 0.001). These findings were also confirmed in individual hospitals.

Conclusions

Dual block HER2 assessment effectively increased HER2 IHC positive rate in resected specimens of GC. We recommended dual block HER2 assessment be promoted in routine clinical practice in GC.

Trial registration

ClinicalTrials.gov, NCT 02843412. Registered 1 July 2016 - Retrospectively registered.

Intratumoral and intertumoral heterogeneity of HER2 immunohistochemical expression in gastric cancer

BACKGROUND

Given the high heterogeneity of tumor tissue in gastric cancer (GC), inaccurate detection of tumor biomarkers will inevitably hamper a precise diagnosis and selection of patients for targeted therapies. Human epidermal growth factor receptor 2 (HER2) has been widely accepted as an underlying treatment biomarker of GC. The objective of this study is to investigate the heterogeneity (both intratumoral and intertumoral) of HER2 expression in GC, and the relationship between heterogeneity and the clinicopathological features.

METHODS

A total of 618 patients with primary gastric adenocarcinoma were recruited, and two formalin-fixed paraffin-embedded (FFPE) tumor-containing blocks of each patient were selected for HER2 immunohistochemical (IHC) assay. Clinicopathological characteristics were recorded, and intratumoral and intertumoral heterogeneity of HER2 IHC expression was determined.

RESULTS

The results indicated that the dual-block assays significantly increased the HER2 overexpression (IHC 2+ and 3+) rate compared with the single paraffin block detection. Approximately 50 % of the cases showed intratumoral HER2 heterogeneity within a single tissue section, and 30.10 % of cases showed intertumoral heterogeneity between a patient's two blocks. Furthermore, intertumoral heterogeneity was associated with tumors of small size (P = 0.029) and distal location (P = 0.032) characters, while the intratumoral heterogeneity was correlated with poorly differentiated carcinomas. Laurén's diffuse type showed a notably higher intratumoral heterogeneity rate, and the mixed type exhibited higher intertumoral HER2 discordance between the dual-block cohorts (P < 0.001). Besides, HER2 heterogenous overexpression was not associated with age, gender, type of resection, lymphatic or venous invasion, perineural invasion or pTNM (P > 0.05) for both cohorts.

CONCLUSION

The research findings in this paper indicate that the intratumoral and intertumoral heterogeneity of HER2 overexpression is common in GC patients, and these variations are associated with certain clinicopathological features. We highly recommend multi-block HER2 assessment for accurate diagnosis of GC.

Comparing human epidermal growth factor receptor 2 amplification and expression using immunohistochemistry and silver in situ hybridisation in gastric carcinoma and lymph node metastasis

Detecting the amplification and expression of human epidermal growth factor receptor (HER2) is important for planning trastuzumab treatment for patients with gastric carcinoma. The present study aimed to analyse HER2 amplification and expression in primary gastric adenocarcinoma tumours and metastatic lymph nodes using microarray methods, and to assess the potential contribution of these methods to treatment planning. In total, 60 patients with lymph node metastasis were included in the present study. Microarray blocks were obtained from the tissue blocks of primary tumours and metastatic lymph nodes. HER2 expression and amplification were investigated using immunohistochemical and silver in situ hybridisation (SISH) methods, respectively. Following immunohistochemical evaluation of HER2 in primary tumours, the sensitivity and specificity of the microarray method relative to the single block method were 69 and 100%, respectively. For HER2 detection in microarray block sections from primary tumours, the sensitivity and specificity of the SISH method relative to immunohistochemistry were 56 and 100%, respectively. When using SISH in microarray blocked sections, there was a high degree of concordance (98% concordance rate) between HER2 amplification in the primary tumour and the metastatic lymph node. Furthermore, the sensitivity and specificity of metastatic lymph node results relative to those of the primary tumour were 100 and 98%, respectively. Overall, the single block method was more reliable compared with the microarray method for planning treatment. When microarray blocking was used, a large number of samples must be tested to ensure reliable results. The immunohistochemical method is recommended as the first step as SISH alone increases the risk of false-negative results. Assessing HER2 amplification for treatment planning would be beneficial for primary tumours, as well as metastatic lymph nodes.

The age variation of HER2 immunohistochemistry positive rate in biopsy specimens of gastric cancer

AIMS

The aim of this study was to explore HER2 status and characteristics in biopsy specimens of gastric cancer (GC) in Chinese population.

METHODS AND RESULTS

A total of 27,787 biopsy specimens of GC from 103 hospitals were obtained. Immunohistochemistry (IHC) staining of HER2 was performed. Overall HER2 IHC positive rate was 11.2 %. HER2 positive rate elevated with the increase of age in total patients and both genders. The rates were 7.1 %, 8.1 %, 9.0 %, 10.9 %, 11.8 %, 12.6 %, and 12.1 % when patient age was ≤30, 31-40, 41-50, 51-60, 61-70, 71-80, and >80, respectively (P < 0.001). In male, the rates were 6.5 %, 8.4 %, 9.6 %, 11.5 %, 12.4 %, 13.3 %, and 12.1 % (P < 0.001). In female, the rates were 7.4 %, 7.9 %, 8.0 %, 9.0 %, 9.6 %, 10.6 %, and 11.9 % (P = 0.128). The changes in male were more dramatic than in female (P < 0.001). Furthermore, the proportion of the intestinal type GCs increased with age in total patients and both genders (P < 0.001), and in male the changes were more dramatic (P < 0.001). While the proportion of the diffuse type showed the opposite tendency to that of the intestinal type (P < 0.001). HER2 IHC positive rate showed a positive correlation with the proportion of the intestinal type (r=0.986, P < 0.001), and a negative correlation with the proportion of the diffuse type (r=0.984, P < 0.001).

CONCLUSIONS

The HER2 IHC positive rate showed age variation in biopsy specimens of GC. In male the variation was more dramatic than in female. The variation of HER2 positive rate can be attributed to the age variation of the Lauren subtypes.

Late stage gastric cancer patients with extra gained HER2 positivity by dual block assessment may not show compromised efficacy to trastuzumab treatment

Dual block HER2 assessment can effectively increase the HER2 positive rate in resected specimens of gastric cancer (GC). The aim of this study is to explore whether GC patients with extra gained HER2 positivity by dual block assessment can benefit from trastuzumab therapy. Twenty-eight GC patients receiving gastrectomy prior to trastuzumab treatment were retrospectively analyzed. All the cases routinely accepted dual block HER2 assessment. The cases were divided into 2 cohorts based on HER2 status: cohort A with concordant HER2 results and cohort B with discordant HER2 results between the two blocks (cases with extra gained HER2 positivity). Response rate (RR), progress free survival (PFS) and overall survival (OS) were compared between the two cohorts. The results showed that no significant differences were found between the two cohorts in main clinicopathologic characteristics. No statistical difference was found in response rate (47.6% vs 57.1%) (P=1.0), either. The two cohorts did not demonstrate statistical differences in the PFS (10.5 months (95%CI 6.4-14.6) vs 8.0 months (95%CI 3.2-12.8), P=0.686) and the OS (23.3 months (95%CI 12.1-34.5) vs 20.0 months (95%CI 10.1-29.9), P=0.776). In conclusion, our study suggests that patients with extra gained HER2 positivity may not show compromised efficacy to trastuzumab treatment.

Prevalence of HER2 Expression and Its Correlation with Clinicopathological Parameters in Gastric or Gastroesophageal Junction Adenocarcinoma in North-East Indian Population

Objective: Human epidermal growth factor receptor 2 (erbb2/HER2) overexpression, has now been implicated in advanced gastric and gastroesophageal junction cancers. The study was conducted to determine the rate of HER2 positivity in patients with locally advanced or metastatic gastric and gastroesophageal adenocarcinoma in North-East India and to assess the impact of various demographic and clinical parameters on HER2 positivity. Methods: A total of 68 patients of age >18 years of gastric and gastroesophageal adenocarcinoma diagnosed on histopathological examination from September 2016 to February 2018 at Dr B Borooah Cancer Institute, Assam were enrolled for the observational (epidemiological) study. All patients were subjected to the HER2 immunohistochemistry test using a FDA-approved, standardized test kit. HER2 expression was correlated with various demographic and clinicopathological parameters. Results: The overall rate of HER2 positivity in the population studied was 56% (n=38). The rate was non-significantly higher in male, older age group (>60 years) and Hindu population. Similarly, HER2 positivity rate was higher in patients with well differentiated histology and was more common in patients with stage II and III diseases, but neither of the associations is statistically significant. HER2 positivity rate was significantly higher in proximal and in GEJ tumours (56% versus 44%, P=0.002). Conclusion: HER2 overexpression was evident in 56% of the North-East Indian patients with locally advanced and metastatic gastric and gastroesophageal adenocarcinoma. The overexpression correlated significantly with primary tumour site. Routine testing of gastric and gastroesophageal tumours for HER2 expression is recommended to provide a therapeutic advantage in Indian patients.

Impact of Specimen Type and Specimen Number on HER2 Status in Gastroesophageal Junction and Gastric Adenocarcinoma

OBJECTIVES

Human epidermal growth factor receptor 2 (HER2) is expressed in some gastric and gastroesophageal junction adenocarcinomas. There were two goals: assess the impact of specimen type on HER2 status and evaluate HER2 concordance with multiple specimens.

METHODS

All cases were evaluated by immunohistochemistry (IHC) for HER2 and interpreted using established criteria. Fluorescence in situ hybridization (FISH) was performed on a subset.

RESULTS

Of 460 specimens, 83.9% were IHC negative, 5.4% were equivocal, and 10.7% were IHC positive. Of those with FISH testing, 78.5% were FISH negative, and 21.5% were FISH positive. IHC-FISH concordance for biopsy specimens, resections, and metastases was 82%, 84%, and 86%, respectively. With one vs two vs three or more specimens, the HER2-positive rate increased from 10.5% to 18.1% to 24.1%, respectively.

CONCLUSIONS

HER2 testing may be performed on biopsy specimens with a relatively high concordance rate with resection specimens, and if multiple samples are analyzed from a single patient, the HER2-positive rate increases over twofold.

Poor efficacy response to trastuzumab therapy in advanced gastric cancer with homogeneous HER2 positive and non-intestinal type

Introduction

Factors affecting trastuzumab efficacy in advanced gastric cancer (GC) are largely unknown. Heterogeneity is a notable feature of HER2 in GC. Whether the heterogeneity influences trastuzumab efficacy is still unknown.

Results

The HER2^homogeneous group and HER2^{heterogeneous} group showed no statistical difference in RR (46.4% vs 55.0%, P = 0.558), PFS (5.80 vs 6.30 months, P = 0.804) and OS (16.00 vs 16.00 months, P = 0.787). The Lauren^intestinal group and Lauren^{non-intestinal} group demonstrated no discrepancy in PFS (6.00 vs 6.00 months, P = 0.912) and OS (16.50 vs 14.00 months, P = 0.227). However, by combining HER2 heterogeneity and Lauren classification, PFS and OS of HER2^homogeneous/Lauren^{non-intestinal} subgroup was the shortest among the 4 subgroups (P = 0.012 and P = 0.037), which was much shorter than the other patients (PFS:3.00 vs 6.30 months, P = 0.003; OS: 4.50 vs 16.50 months, P = 0.004). Univariate and multivariate analysis showed that HER2 heterogeneity combined with Lauren classification was an independent prognostic factor in both PFS (P = 0.031 and P = 0.002) and OS (P = 0.039 and P = 0.013).

Materials and Methods

48 patients with HER2 positive advanced GCs accepting trastuzumab treatment were retrospectively analyzed. Based on HER2 heterogeneity, the patients were divided into a HER2^homogeneous group and a HER2^{heterogeneous} group. Response rate (RR), progression free survival (PFS), and overall survival (OS) were compared. Main clinicopathological factors including Lauren classification were subjected to subgroup analysis.

Conclusions

HER2 heterogeneity alone may not correlate with trastuzumab efficacy in HER2 positive advanced GCs. HER2 heterogeneity combined with Lauren classification may help to identify a subgroup with poor response to trastuzumab which is homogeneous HER2 positive and non-intestinal type.

Oesophageal cancer

Oesophageal cancer is the sixth most common cause of cancer-related death worldwide and is therefore a major global health challenge. The two major subtypes of oesophageal cancer are oesophageal squamous cell carcinoma (OSCC) and oesophageal adenocarcinoma (OAC), which are epidemiologically and biologically distinct. OSCC accounts for 90% of all cases of oesophageal cancer globally and is highly prevalent in the East, East Africa and South America. OAC is more common in developed countries than in developing countries. Preneoplastic lesions are identifiable for both OSCC and OAC; these are frequently amenable to endoscopic ablative therapies. Most patients with oesophageal cancer require extensive treatment, including chemotherapy, chemoradiotherapy and/or surgical resection. Patients with advanced or metastatic oesophageal cancer are treated with palliative chemotherapy; those who are human epidermal growth factor receptor 2 (HER2)-positive may also benefit from trastuzumab treatment. Immuno-oncology therapies have also shown promising early results in OSCC and OAC. In this Primer, we review state-of-the-art knowledge on the biology and treatment of oesophageal cancer, including screening, endoscopic ablative therapies and emerging molecular targets, and we discuss best practices in chemotherapy, chemoradiotherapy, surgery and the maintenance of patient quality of life.

Tumor containing fragment number influences immunohistochemistry positive rate of HER2 in biopsy specimens of gastric cancer

Background

HER2 assessment in biopsy specimens of gastric cancer (GC) is challenging because of the intratumoral heterogeneity. False negative results may be get because of limited biopsy material. The aim of this study is to explore how tumor-containing fragment number and biopsy specimen number affect HER2 immunohistochemistry (IHC) positive rate.

Methods

Eight hundred and ninety biopsy specimens and 459 paired resected specimens were collected. IHC staining of HER2 was performed. HER2 IHC positive (scored 3+) rate was compared based on tumor-containing fragment number, biopsy specimen number, average size and tumor tissue proportion of tumor-containing fragments. The positive predictability of biopsy specimens to resected specimens was analyzed based on tumor fragment number.

Results

HER2 IHC positive rates were 2.0, 3.5, 7.0, 13.2, 17.1, and 15.9% when tumor fragment numbers were 1, 2, 3, 4, 5 and 6 respectively. The rate rose with the increase of tumor fragment number (P = 0.004). ROC curve analysis showed that biopsy specimens exhibited positive predictability when tumor fragment number reached 3, but showed better performance when the number was ≥4 (P < 0.05). After fragment number reached 4, no statistic differences were reached in either HER2 IHC positive rate or positive predictability with further increase of the number (P > 0.05). HER2 IHC positive rate was not associated with biopsy number (P = 0.127), average size of tumor fragments (P = 0.397), and tumor tissue proportion of tumor fragments (P = 0.825) directly.

Conclusions

The number of tumor-containing fragments influences HER2 IHC positive (scored 3+) rate. Greater than or equal to 4 (≥4) tumor fragments give better results in the positive rate as well as positive predictability. We recommend the number of tumor containing fragments be described in the HER2 IHC pathology reports for clinical reference in endoscopic biopsy specimens of GC.

HER2 Testing and Clinical Decision Making in Gastroesophageal Adenocarcinoma: Guideline From the College of American Pathologists, American Society for Clinical Pathology, and the American Society of Clinical Oncology

Context ERBB2 (erb-b2 receptor tyrosine kinase 2 or HER2) is currently the only biomarker established for selection of a specific therapy for patients with advanced gastroesophageal adenocarcinoma (GEA). However, there are no comprehensive guidelines for the assessment of HER2 in patients with GEA. Objectives To establish an evidence-based guideline for HER2 testing in patients with GEA, formalize the algorithms for methods to improve the accuracy of HER2 testing while addressing which patients and tumor specimens are appropriate, and to provide guidance on clinical decision making. Design The College of American Pathologists (CAP), American Society for Clinical Pathology (ASCP), and the American Society of Clinical Oncology (ASCO) convened an Expert Panel to conduct a systematic review of the literature to develop an evidence-based guideline with recommendations for optimal HER2 testing in patients with GEA. Results The Panel is proposing 11 recommendations with strong agreement from the open comment participants. Recommendations The Panel recommends that tumor specimen(s) from all patients with advanced GEA, who are candidates for HER2-targeted therapy, should be assessed for HER2 status before the initiation of HER2-targeted therapy. Clinicians should offer combination chemotherapy and an HER2-targeted agent as initial therapy for all patients with HER2-positive advanced GEA. For pathologists, guidance is provided for morphologic selection of neoplastic tissue, testing algorithms, scoring methods, interpretation and reporting of results, and laboratory quality assurance. Conclusion This guideline provides specific recommendations for assessment of HER2 in patients with advanced GEA while addressing pertinent technical issues and clinical implications of the results.

HER2 Testing and Clinical Decision Making in Gastroesophageal Adenocarcinoma: Guideline From the College of American Pathologists, American Society for Clinical Pathology, and American Society of Clinical Oncology

CONTEXT

- ERBB2 (erb-b2 receptor tyrosine kinase 2 or HER2) is currently the only biomarker established for selection of a specific therapy for patients with advanced gastroesophageal adenocarcinoma (GEA). However, there are no comprehensive guidelines for the assessment of HER2 in patients with GEA.

OBJECTIVES

- To establish an evidence-based guideline for HER2 testing in patients with GEA, to formalize the algorithms for methods to improve the accuracy of HER2 testing while addressing which patients and tumor specimens are appropriate, and to provide guidance on clinical decision making.

DESIGN

- The College of American Pathologists, American Society for Clinical Pathology, and American Society of Clinical Oncology convened an expert panel to conduct a systematic review of the literature to develop an evidence-based guideline with recommendations for optimal HER2 testing in patients with GEA.

RESULTS

- The panel is proposing 11 recommendations with strong agreement from the open-comment participants.

RECOMMENDATIONS

- The panel recommends that tumor specimen(s) from all patients with advanced GEA, who are candidates for HER2-targeted therapy, should be assessed for HER2 status before the initiation of HER2-targeted therapy. Clinicians should offer combination chemotherapy and a HER2-targeted agent as initial therapy for all patients with HER2-positive advanced GEA. For pathologists, guidance is provided for morphologic selection of neoplastic tissue, testing algorithms, scoring methods, interpretation and reporting of results, and laboratory quality assurance.

CONCLUSIONS

- This guideline provides specific recommendations for assessment of HER2 in patients with advanced GEA while addressing pertinent technical issues and clinical implications of the results.

HER2 Testing and Clinical Decision Making in Gastroesophageal Adenocarcinoma: Guideline From the College of American Pathologists, American Society for Clinical Pathology, and American Society of Clinical Oncology

CONTEXT

ERBB2 (erb-b2 receptor tyrosine kinase 2 or HER2) is currently the only biomarker established for selection of a specific therapy for patients with advanced gastroesophageal adenocarcinoma (GEA). However, there are no comprehensive guidelines for the assessment of HER2 in patients with GEA.

OBJECTIVES

To establish an evidence-based guideline for HER2 testing in patients with GEA, to formalize the algorithms for methods to improve the accuracy of HER2 testing while addressing which patients and tumor specimens are appropriate, and to provide guidance on clinical decision making.

DESIGN

The College of American Pathologists, American Society for Clinical Pathology, and American Society of Clinical Oncology convened an expert panel to conduct a systematic review of the literature to develop an evidence-based guideline with recommendations for optimal HER2 testing in patients with GEA.

RESULTS

The panel is proposing 11 recommendations with strong agreement from the open-comment participants.

RECOMMENDATIONS

The panel recommends that tumor specimen(s) from all patients with advanced GEA, who are candidates for HER2-targeted therapy, should be assessed for HER2 status before the initiation of HER2-targeted therapy. Clinicians should offer combination chemotherapy and a HER2-targeted agent as initial therapy for all patients with HER2-positive advanced GEA. For pathologists, guidance is provided for morphologic selection of neoplastic tissue, testing algorithms, scoring methods, interpretation and reporting of results, and laboratory quality assurance.

CONCLUSIONS

This guideline provides specific recommendations for assessment of HER2 in patients with advanced GEA while addressing pertinent technical issues and clinical implications of the results.

HER2 heterogeneity in gastric/gastroesophageal cancers: From benchside to practice

HER2 is overexpressed in approximately 10%-20% of gastric and gastroesophageal junction carcinomas. In these types of cancer, accurate assessment of HER2 status is mandatory, for selecting patients who may benefit from targeted therapies with anti-HER2 drugs such as Trastuzumab. This manuscript focuses on HER2 in gastric carcinogenesis, on optimal evaluation of HER2 and on the possible causes which may contribute to inaccurate HER2 evaluation. Similarly to breast cancer HER2 evaluation, standardization of HER2 testing in gastric cancer is necessary in diagnostic practice. The three principle aspects which require consideration are: (1) the choice of sample with regards to cancer morphology - intestinal vs diffuse areas; (2) the choice of scoring criteria - use of HER2 scoring criteria specific for gastric cancer; and (3) the choice of HER2 evaluation methods - use of an algorithm in which both immunohistochemistry and in situ hybridization play a role. Problematic issues include: (1) pre-analytic variables with particular emphasis on fixation; (2) recommended methodology for HER2 assessment (immunohistochemistry vs in situ hybridization); (3) HER2 heterogeneity both within the primary tumor and between primary tumor and metastases; (4) reliability of biopsies in HER 2 evaluation; and (5) quantity of sample (FFPE blocks from surgical specimens or endoscopic biopsies) necessary for an adequate assessment.

Gastric Adenocarcinoma: An Update on Genomics, Immune System Modulations, and Targeted Therapy

Gastric adenocarcinoma (GAC) is a global health burden on all societies, and it was the third-leading cause of cancer-related mortality in 2012, causing 723,000 deaths worldwide. The prognosis of patients with metastatic GAC remains poor, with a median overall survival of less than 1 year in patients treated with currently available therapies. A limited number of therapeutic agents is currently available. Recent additions to the armamentarium include trastuzumab and ramucirumab, which have shown some survival advantage when added to cytotoxic(s). Genomic analyses have defined various genotypes of GACs. The novel genomic knowledge can lead to discovery of novel targets and novel therapeutic agents. In this update, we focus on the current genomic data, targeted therapies including immune system modulators, and expand on HER2/neu testing and the use of agents against this target. Several other facets of GAC and its therapy are not to be included in this review but have been discussed elsewhere.