HER-2 overexpression and targeted treatment by trastuzumab in a very old patient with gastric cancer

The advent of precision therapy in gastrointestinal malignancies: Targeting the human epidermal growth factor receptor family in colorectal and esophagogastric cancer

Until recently, systemic therapy for gastrointestinal malignancies was restricted to relatively noncancer-specific cytotoxic chemotherapy. Over the last 15 years targeted therapies have become available, most notably bevacizumab in the case of advanced colorectal cancer. Unfortunately, there are no predictive biomarkers to guide the use of this agent. In this review article, we describe the advent of “Precision Medicine” (in part, the use of patient-specific molecular markers to inform treatment) in gastrointestinal cancers: The use of monoclonal antibodies targeting epidermal growth factor receptor in advanced colorectal cancer, and human epidermal growth factor receptor 2-neu in advanced esophagogastric cancer. In both instances, biomarkers help in selecting appropriate patients for such treatment.

A critical review of HER2-positive gastric cancer evaluation and treatment: from trastuzumab, and beyond

Identification of the importance of human epidermal growth factor receptor-2 (HER2) status, biomarker testing and the development of anti-HER2 treatments have changed the prognosis of breast and gastric cancers. The addition of trastuzumab to chemotherapy has improved outcomes for patients with HER2-positive metastatic adenocarcinoma of the stomach and gastroesophageal junction, but some relevant issues remain to be elucidated or will emerge with new drugs. This article reviews the current state of HER2 in gastric cancer focusing on diagnostic and anti-HER2 targeted treatment issues and the role of trastuzumab in localized disease, and its combination or integration with new therapies.

Prognosis of HER2 over-expressing gastric cancer patients with liver metastasis

AIM: To study the risk factors for liver metastasis and the prognosis in patients with human epidermal growth factor receptor 2 (HER2) over-expressing gastric cancer (GC).

METHODS: A total of 84 GC patients recruited from the General Hospital of the People’s Liberation Army (PLA) between 2003 and 2010 were randomly enrolled in this study. HER2 expression was detected by immunohistochemistry in 84 GC patients with liver metastases. The study group consisted of 66 men and 18 women, with an average age of 54 years (range: 19-74 years). Liver metastasis was diagnosed by magnetic resonance imaging or computed tomography. Patients were followed-up and predictive factors of liver metastasis were evaluated.

RESULTS: The median follow-up period was 47 mo (range: 6-85 mo). The characteristics of 35 (25.7%) patients with HER2 over-expression of liver metastatic GC are presented. HER2 over-expression was detected in 23 out of 49 (46.9%) patients with intestinal GC, and 9 out of 35 (25.7%) patients with diffuse GC. 29 out of 59 (49.2%) patients aged < 60 years were HER2-positive, while 8 out of 25 (32%) patients aged ≥ 60 were HER2-positive; a significant difference (P < 0.05). Univariate analysis (log-rank test) showed that HER2 over-expression, sex, Lauren classification, differentiation and disease-free interval were correlated with poor survival (P < 0.05). Survival analysis with a survival curve showed that HER2 over-expression was significantly relevant, with a reduced survival time in GC patients with liver metastases (P < 0.01). 2-year survival was not associated with the patient’s age. A disease-free survival longer than 12 mo has a significant association with extended overall survival (OS) in GC patients with liver metastases. The median survival time after the diagnosis of liver metastases was 18 mo [95% confidence interval (CI): 9.07-26.94] among HER2 positive GC patients with liver metastases. In comparison, for 49 (69.4%) out of 84 HER2 negative patients with liver metastatic GC, the median survival time was 47 mo (95% CI: 19.37-74.63). In patients with HER2 positive liver metastatic GC, the median OS was significantly shorter than in HER2 negative patients (median, 20.32 mo; 95% CI: 16.51-24.13 vs median, 50.14 mo; 95% CI: 37.83-62.45; P < 0.01).

CONCLUSION: HER2 over-expressing GC patients with liver metastases have a poor prognosis. Overall survival was significantly lower in HER2 positive patients. HER2-overexpression is correlated with a lower survival rate.

Human epidermal growth factor receptor-2 gene amplification in gastric cancer using tissue microarray technology

AIM: To assess human epidermal growth factor receptor-2 (HER2)-status in gastric cancer and matched lymph node metastases by immunohistochemistry (IHC) and chromogenic in situ hybridization (CISH).

METHODS: 120 cases of primary gastric carcinomas and 45 matched lymph node metastases from patients with full clinicopathological features were mounted onto multiple-punch and single-punch tissue microarrays, respectively, and examined for HER2 overexpression and gene amplification by IHC and CISH.

RESULTS: Twenty-four tumors (20%) expressed HER2 immunohistochemically. An IHC score of ≥ 2+ was observed in 20 tumors (16.6%). HER2 amplification was detected by CISH in 19 tumors (15.8%) and in their matched lymph node metastases. A high concordance rate was found between HER2 positivity (as detected by IHC) and HER2 gene amplification (as detected by CISH), since 19 of the 20 IHC positive cases were amplified (95%). All amplified cases had 2+ or 3+ IHC results. Amplification was associated with intestinal phenotype (P < 0.05). No association with grading, staging or survival was found.

CONCLUSION: In gastric cancer, HER2 amplification is the main mechanism for HER2 protein overexpression and is preserved in lymph node metastases.

Positive response to trastuzumab in a case of HER2-overexpressing metastatic gastric cancer that presented as severe thrombocytopenia

BACKGROUND

Trastuzumab, a humanized monoclonal antibody directed against human epidermal growth factor receptor 2 (HER2), has been shown to be active against metastatic gastric cancers that overexpress HER2.

CASE REPORT

A 47-year-old man presented with a headache and visual disturbance. He was subsequently found to have an intracranial hemorrhage. Laboratory testing showed severe thrombocytopenia, and a bone marrow biopsy revealed aggregates of malignant tumor cells. Endoscopic biopsy of an ulcerative lesion of the gastric antrum confirmed signet ring cell carcinoma based on the results of H&E staining. Immunohistochemistry of the tumor cells revealed HER2 overexpression with an intensity of 3+, and silver in situ hybridization showed HER2 gene amplification. The patient was treated with trastuzumab because of the presence of severe thrombocytopenia. After 2 months of trastuzumab therapy, gastric wall thickening and ascites were diminished and thrombocytopenia was markedly improved. Trastuzumab was continued for an additional 3 months.

CONCLUSION

This is the first report of a positive response to trastuzumab in a patient with HER2-overexpressing metastatic gastric cancer that was accompanied by bone marrow involvement and severe thrombocytopenia. This finding is of considerable relevance for difficult cases of metastatic gastric cancer that preclude the administration of aggressive antineoplastic regimens.

HER2 testing in gastric cancer

Molecular therapies targeting HER2 are part of the established drug armamentarium in breast carcinoma. Now the ToGA trial, an international multicenter phase III clinical study, involving 24 countries globally, has shown that the anti-HER2 humanized monoclonal antibody Trastuzumab is effective in prolonging survival in HER2-positive carcinoma of the stomach and the gastroesophageal junction (GEJ). Similarly to breast carcinoma, >20% of gastric cancers show HER2 overexpression and/or amplification, and this percentage increases to 33% in GEJ tumors. Thus, as in breast carcinoma, pathologists are now asked to evaluate HER2 status in gastric carcinoma samples. As validated in the ToGA trial, the HER2 testing criteria that must be used in evaluating both gastric carcinoma biopsies and surgical specimens significantly differ from those routinely applied in breast carcinoma. The main variations with regard to the pattern of reactivity in HER2-expressing cells are as follows: the completeness of membrane staining is not a "conditio sine qua non" and the number of stained cells necessary to consider a case as positive is different. We must also take note of the much more frequent heterogeneity of HER2 positivity in gastric cancer compared with breast carcinoma and the less stringent correlation between HER2 amplification and protein overexpression that is observed in gastric carcinoma, where more than 20% of cases may carry HER2 amplification, although of low level, without HER2 expression. In these patients, in the ToGA trial, there was no apparent benefit from adding Trastuzumab to chemotherapy: for this reason the European Medicines Agency, while approving usage of Trastuzumab for metastatic adenocarcinoma treatment, indicated HER2 testing by immunohistochemistry as first evaluation assay, followed by fluorescence in situ hybridization in 2+ equivocal cases. HER2 testing in gastric carcinoma is a new field, opening several opportunities: for patients with gastric cancer, this is a new promising therapeutic option; for pathologists, strengthening our role in therapy selection and emphasizing our duty of providing accurate and reproducible HER2 testing results; for all interested in understanding the biology of gastric and GEJ cancer and in discovering new possible molecular therapy targets.

Clinical significance of Her-2 protein expression in gastric cancer

AIM: To investigate the correlation between Her-2 protein expression and clinicopathological characteristics of gastric carcinoma.

METHODS: Her-2 protein expression was examined by immunohistochemistry (EliVisionTM plus) in 778 gastric adenocarcinoma specimens.

RESULTS: The positive rate of Her-2 protein overexpression (+++) was 11.35% (68/576). Her-2 protein overexpression was associated with tumor histotype, differentiation, TNM stage, and distant metastasis (all P < 0.05), but not with sex, age, tumor site, and lymph node metastasis (all P > 0.05). Multivariate analysis demonstrated that tumor histotype, differentiation, TNM stage, and distant metastasis were significant predictors of Her-2 protein overexpression in gastric carcinoma (all P > 0.05). Moderate Her-2 protein expression (++) was detected in 5.68% of gastric carcinoma specimens.

CONCLUSION: Detection of Her-2 protein expression may be used to assess the malignant biological behavior and prognosis of gastric cancer. Gastric cancer patients exhibiting Her-2 protein overexpression might constitute potential candidates for new adjuvant therapies that involve the use of humanized monoclonal antibodies.

Simultaneous detection of expression and gene mutations of HER2/neu in Chinese patients with gastric cancer

HER2/neu is one of the few identified oncogenes in tumorigenesis. Attention has been focused on the potential effect of HER2/neu mutations in the tyrosine kinase domain on carcinoma-targeted therapy. However, data concerning HER2/neu mutations in Chinese patients with gastric cancer (GC) are limited. This study aimed to detect the expression and somatic mutations of HER2/neu in Chinese patients with GC. Immunohistochemical staining for HER2/neu was performed on 72 formalin-fixed, paraffin-embedded specimens of GC (40 intestinal and 32 diffuse type). The correlation between the overexpression of HER2/neu and clinicopathological parameters was statistically analyzed. Somatic mutations in the tyrosine kinase domain of HER2/neu in the 72 patients were detected by direct sequencing. In the GC group, overexpression of HER2/neu was detected in 13 of the 72 GC patients and in 4 of the 72 adjacent tissues in the non-tumorous group (18.1 vs. 5.6%, P<0.05). Furthermore, the intestinal type of GC exhibited a higher rate of HER2/neu overexpression than the diffuse type (29.7 vs. 5.7%, P<0.05). The rate of HER2/neu overexpression in stage III-IV (TNM stage) GC cases was significantly higher than that in stage I-II (28.2 vs. 6.6%, P<0.05). HER2/neu overexpression correlated with a significantly less favorable patient survival (P=0.046). No somatic mutations in the tyrosine kinase domain of HER2/neu were detected in tumor tissues or the corresponding non-tumorous ones in the specimens obtained from the 72 Chinese GC patients. Results suggest that overexpression of HER2/neu is a frequent molecular event strongly associated with a poor patient prognosis, whereas the incidence of somatic mutations of the HER2/neu kinase domain is more likely a low-frequency event in Chinese GC patients.

Comparative study on overexpression of HER2/neu and HER3 in gastric cancer

BACKGROUND

Owing to the special importance of the HER family in tumorigenesis, the downstream signaling pathways and effectors have become the key molecules in the strategy of carcinoma-targeted therapy. Recent evidence that HER3 is responsible for tumor resistance to therapeutic agents targeting EGFR or HER2/neu, along with the new findings that HER3 is involved in the process of dedifferentiation of gastric cancer (GC) have highlighted the critical role of HER3 in cancer research. HER3 is becoming a new targeted molecule in cancer treatment. Here, we comparatively investigated the expression of HER2/neu and HER3 in gastric cancer of two pathologic types (intestinal type and diffuse type) using immunohistochemistry (IHC) and analyzed the correlation between overexpression of HER2 and HER3 and clinicopathologic parameters.

METHODS

An IHC study for HER2 and HER3 was performed on 102 formalin-fixed, paraffin-embedded specimens of GC-60 intestinal and 42 diffuse types. The correlation between overexpression of HER2 and HER3 and clinicopathologic parameters was statistically analyzed.

RESULTS

In the GC group, overexpression of HER2 and HER3 was detected in 19 (18.6%) and 14 (13.7%) of 102 GC patients, respectively. In a nontumorous group of 102 specimens, 5 were HER2-positive (4.9%) (18.6% vs. 4.9%, p < 0.01), and 2 were HER3-positive (2.0%) (13.7% vs. 2.0%, p < 0.01). No co-overexpression of HER2 and HER3 was observed. The intestinal type of GC exhibited a higher rate of HER2 overexpression than did the diffuse type (26.7% vs. 7.1%, p < 0.05), whereas the diffuse type of GC exhibited a significantly higher rate of HER3 overexpression than did the intestinal type (26.2% vs. 5.0%, p < 0.01). The overexpression rates of HER2 and HER3 in phase III-IV (TNM stage) disease were significantly higher than that in phase I-II disease (24.0% vs. 7.7%, p < 0.05 and 22.0% vs. 5.8%, p < 0.05, respectively). HER2 and HER3 overexpression was also correlated with a significantly worse survival (p = 0.046 and 0.024, respectively).

CONCLUSIONS

The selective overexpression of HER2 and HER3 in the two histologic types of gastric cancer is strongly associated with a poor prognosis. Being an important member of the HER family, HER3 may become another candidate for molecular-targeted therapy in gastric cancer, especially for the diffuse histologic type.

Toward molecularly selected chemotherapy for advanced gastric cancer: state of the art and future perspectives

In the last few years therapeutic options for gastric cancer patients have slowly, but constantly expanded following the introduction of both new chemotherapy agents and innovative indications for treatment. Along with the medical therapy also our knowledge of the molecular mechanisms underlying this disease has progressively improved. However although the available treatment options have undoubtedly increased no clear definitive indications can be made for a standard chemotherapy regimen and we are still unable to accurately select the appropriate treatment for the appropriate patient. Many molecular determinants of response/toxicity to chemotherapy agents have been identified, but only few of them seem to possess the necessary potential for a subsequent application in the clinical practice. Some of these factors have also been indicated as a therapeutic target for a novel class of anti-cancer compounds. This systematic review will analyse available data about these factors with the aim to constitute a starting point for future research.

ERBBs in the gastrointestinal tract: recent progress and new perspectives

The gastrointestinal epithelium does much more than provide a physical barrier between the intestinal lumen and our internal milieu. It is actively engaged in absorption and secretion of salt and water via ion transporters, exchangers and selective ion channels. It is also a continuously self-renewing epithelium that undergoes ordered growth and differentiation along its vertical axis. From this dual perspective, we will consider the actions of the ERBB family of ligands and receptors in the maintenance of gastrointestinal homeostasis and discuss instances when the actions of this family go awry such as in cancer and Ménétrier's disease.

Locally advanced and metastatic gastric cancer: current management and new treatment developments

The management of gastric cancer remains a challenge. In recent years, the most important advances have been achieved in the adjuvant setting for patients with locally advanced disease, where significant survival benefits have been demonstrated for both perioperative chemotherapy and adjuvant chemoradiotherapy. These findings have changed the standard of care for patients with resectable disease. In the setting of metastatic gastric cancer, the development of new cytotoxic regimens must consider the balance between efficacy and toxicity in patients whose overall prognosis is poor. Major advances in recent years include the development of orally administered fluoropyrimidine analogues, which can be used in place of intravenous fluorouracil, and the addition of newer agents such as oxaliplatin and docetaxel, which have demonstrated efficacy in patients with advanced disease. Targeted therapies have had a major impact on the management of certain malignancies, and while their evaluation in the treatment of advanced gastric cancer remains early, it is likely that these agents will continue to be developed and studied in combination with chemotherapy. This article reviews recent advances in the use of chemotherapy for advanced gastric cancer. Targeted therapies, their mechanisms of action and emerging data supporting their use in gastric cancer are also discussed. The two randomized phase III trials supporting adjuvant therapy for locally advanced, resectable gastric cancer are discussed in detail, together with strategies for future trials in this area. Overall, there remains optimism that further incremental gains will be achieved with future studies combining chemotherapy, radiotherapy and targeted therapies, both in the adjuvant and metastatic disease settings.