Role of Her-2 in Gastrointestinal Tumours beyond Gastric Cancer: A Tool for Precision Medicine

Gastrointestinal (GI) tumors account for a quarter of all the cancer burden and a third of the global cancer-related mortality. Among them, some cancers retain a dismal prognosis; therefore, newer and innovative therapies are urgently needed in priority disease areas of high-unmet medical need. In this context, HER2 could be a relevant prognostic and predictive biomarker acting as a target for specific drugs. However, if the role of HER2 has been object of investigation for several years in gastric cancer, it is not well established in other GI malignancies. The aim of this narrative review was to portray the current landscape of the potential role of HER2 as a predictive biomarker for GI tumors beyond gastric cancer. In colon cancer, the benefit from anti-HER2 therapies is less clear than in gastric neoplasms for the lack of controlled studies. Pancreatic, biliary tract adenocarcinomas and hepatocarcinoma may derive a less clear clinical benefit by using anti-HER2 agents in HER2 positive tumors. Overall, the results are promising and seem to suggest that the integration of multiple modalities of therapies can optimize the cancer care. However, further prospective trials are needed to validate the use of personalized targeted therapies in this field.

Molecular Targets in Biliary Carcinogenesis and Implications for Therapy

Biliary tract cancers (BTCs) encompass a group of invasive carcinomas, including cholangiocarcinoma (intrahepatic, perihilar, or extrahepatic), and gallbladder carcinoma. Approximately 90% of patients present with advanced, unresectable disease and have a poor prognosis. The latest recommendation is to treat advanced or metastatic disease with gemcitabine and cisplatin, although chemotherapy has recorded modest survival benefits. Comprehension of the molecular basis of biliary carcinogenesis has resulted in experimental trials of targeted therapies in BTCs, with promising results. This review addresses the emerging role of targeted therapy in the treatment of BTCs. Findings from preclinical studies were reviewed and correlated with the outcomes of clinical trials that were undertaken to translate the laboratory discoveries.

IMPLICATIONS FOR PRACTICE

Biliary tract cancers are rare. Approximately 90% of patients present with advanced, unresectable disease and have a poor prognosis. Median overall and progression-free survival are 12 and 8 months, respectively. Because chemotherapy has recorded modest survival benefits, targeted therapies are being explored for personalized treatment of these cancers. A comprehensive review of targeted therapies in biliary tract cancers was undertaken to present emerging evidence from laboratory and/or molecular studies as they translate to clinical trials and outcomes. The latest evidence on this topic is presented to clinicians and practitioners to guide decisions on treatment of this disease.

State-of-the-art in the management of locally advanced and metastatic gallbladder cancer

PURPOSE OF REVIEW

Gallbladder carcinoma (GBC), classified as a biliary tract cancer (BTC) along with intrahepatic and extrahepatic cholangiocarcinomas, is a rare disease in Western countries, but a highly prevalent disease in Chile, other countries in Latin America, India and Japan. It commonly presents at an advanced stage, and has limited therapeutic options. Cisplatin/gemcitabine has emerged as the first-line standard of care for patients with advanced BTCs, but the prognosis remains poor. Development of molecularly targeted therapies in advanced BTC remains challenging.

RECENT FINDINGS

Comprehension of the molecular events in gallbladder carcinogenesis may provide a novel targeted therapeutic approach, and early stage clinical trials with targeted therapies appear promising, although the relationship between subsets of patients with positive responses to therapy and tumor genetics requires further exploration. Recent developments in targeted therapeutics, directed against several key signalling pathways in BTC, including epidermal growth factor receptor, angiogenesis, and the mitogen-activated protein kinase pathway will be discussed, in addition to the potential application of prognostic factors and markers.

SUMMARY

The future therapeutic spectrum for BTC and GBC will likely encompass novel combinations of targeted therapies with cytostatics in scientifically and molecularly directed schedules, thus permitting fewer mechanisms of escape for tumor cells.

The present and the future landscape of treatment of advanced hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a highly lethal disease that is resistant to conventional cytotoxic drugs. Historically, effective systemic treatment options have not been available for patients with unresectable advanced disease. However, an improved understanding of the molecular mechanisms that regulate tumor initiation and progression over the past few years has led to the development of novel molecularly-targeted therapies that specifically block the different cellular signaling pathways involved. Recently, the antiangiogenesis and Raf kinase inhibitor, sorafenib showed a survival advantage in advanced stage HCC in two randomized, double-blind, controlled trials. These positive results were the first to demonstrate the efficacy of molecularly-targeted therapies in advanced HCC. Moreover, results from phase I and II trials evaluating other agents in this disease are promising and are under active clinical development. In the near future, we expect to have more data, knowledge, and evidence regarding the use of molecularly-targeted therapies in advanced HCC, both as single agents and in combination regimens. In this review, we will summarize the data concerning the present standard treatment for advanced HCC and discuss the newest, most promising clinical research that may affect the future treatment of this disease.

Targeted therapy for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide. The major etiologies and risk factors for development of HCC are well defined and some steps of hepatocellular carcinogenesis have been elucidated. Despite these scientific advances and the implementation of measures for early detection of HCC in patients who are at risk of this disease, survival of patients has not improved greatly over the past three decades. This situation is partly due to the limited therapeutic options available. While surgery and percutaneous or transarterial interventions are effective for patients with limited or compensated underlying liver disease, more than 80% of patients present with multifocal HCC and/or advanced liver disease, or have comorbidities at the time of diagnosis. Treatment options for these patients have previously been limited to best supportive care. The effectiveness of targeted therapy with monoclonal antibodies or small-molecule kinase inhibitors has now been demonstrated for the treatment of different tumors. In 2007, the multitargeted kinase inhibitor, sorafenib, was found to prolong survival significantly for patients with advanced HCC. This Review discusses the mechanisms of targeted therapies and clinical studies that have investigated these therapies in patients with HCC. Perspectives for future developments are also provided.

Molecular targeted therapy for hepatocellular carcinoma

A majority of patients with HCC present with advanced disease and are not candidates for liver transplantation, surgical resection, or regional therapy. Systemic cytotoxic chemotherapy agents are minimally effective, can have significant toxicity, and have not been shown to improve patient survival. Hepatocellular carcinomas are inherently chemotherapy-resistant tumors and are known to overexpress the multidrug resistance genes. Hepatocellular carcinoma is a very heterogeneous disease in terms of its etiology, molecular carcinogenic mechanisms, and biological behavior, which complicate our ability to identify rational molecular therapeutic "targets." Nearly every pathway involved in carcinogenesis is altered to some degree in HCC. Changes in hepatocyte growth factor expression, intracellular signaling, protease and matrix metalloproteinase expression, and oncogene expression are seen in HCC. The recent demonstration, in randomized clinical trials, of survival benefit for HCC patients treated with the oral agent sorafenib is encouraging progress in the development of molecularly targeted anticancer agents in HCC.

Molecular therapy for the treatment of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide. Conventional cytotoxic chemotherapy has failed to show a substantial benefit for patients with HCC. Recently, a number of new drugs targeting molecular mechanisms involved in liver cell transformation have entered into clinical trials and led to encouraging results. In this review we summarise this data and point to a number of new compounds, which are currently being tested and can potentially broaden our therapeutic arsenal even further.

New drugs for the treatment of hepatocellular carcinoma

Treatment of hepatocellular carcinoma has dramatically changed in the last years. The better knowledge of the molecular mechanisms responsible of tumor initiation and progression has allowed the development of molecular targeted therapies that specifically block the disrupted pathways. Among all these new agents, Sorafenib is the only one that has shown efficacy in terms of survival in advanced stage in two randomized, double-blind, controlled trials. The positive result of these two trials are the proof of the efficacy of molecular targeted therapies in hepatocellular carcinoma and opens the door to multipathway blockade and the use of these targeted therapies in the adjuvant setting. Other agents have shown promising results in phase 1-2 trials but further studies are needed to demonstrate their efficacy. In the next years, efforts should be directed to identifying genomic and proteomic profiling that will help us to assess the prognosis and to define what treatment benefits whom, ultimately giving way to personalized medicine.

Role of ErbB family receptor tyrosine kinases in intrahepatic cholangiocarcinoma

Aberrant expression and signaling of epidermal growth factor receptor (ErbB) family receptor tyrosine kinases, most notably that of ErbB2 and ErbB1, have been implicated in the molecular pathogenesis of intrahepatic cholangiocarcinoma. Constitutive overexpression of ErbB2 and/or ErbB1 in malignant cholangiocytes has raised interest in the possibility that agents which selectively target these receptors could potentially be effective in cholangiocarcinoma therapy. However, current experience with such ErbB-directed therapies have at best produced only modest responses in patients with biliary tract cancers. This review provides a comprehensive and critical analysis of both preclinical and clinical studies aimed at assessing the role of altered ErbB2 and/or ErbB1 expression, genetic modifications, and dysregulated signaling on cholangiocarcinoma development and progression. Specific limitations in experimental approaches that have been used to assess human cholangiocarcinoma specimens for ErbB2 and/or ErbB1 overexpression and gene amplification are discussed. In addition, current rodent models of intrahepatic cholangiocarcinogenesis associated with constitutive ErbB2 overexpression are reviewed. Select interactive relationships between ErbB2 or ErbB1 with other relevant molecular signaling pathways associated with intrahepatic cholangiocarcinoma development and progression are also detailed, including those linking ErbB receptors to bile acid, cyclooxygenase-2, interleukin-6/gp130, transmembrane mucins, hepatocyte growth factor/Met, and vascular endothelial growth factor signaling. Lastly, various factors that can limit therapeutic efficacy of ErbB-targeted agents against cholangiocarcinoma are considered.

The impact of new data in the treatment of advanced hepatocellular carcinoma. Curr Oncol Rep. 2008;10:199-205. [PMID: 18765149 DOI: 10.1007/s11912-008-0031-x]

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide, causing 500,000 deaths yearly. The risk factors mostly responsible for the rising incidence of HCC in the Western hemisphere are hepatitis C, alcoholic cirrhosis, and nonalcoholic steatohepatitis, which most commonly leads to HCC in the setting of cirrhosis. Over the past 30 years, several chemotherapeutic single agents and combinations have been tested in HCC, yet none have demonstrated any improvement in survival. Recently, the multitargeted anti-angiogenic and Raf kinase inhibitor sorafenib has shown a survival advantage as a single agent and improved outcomes in combination with doxorubicin. Other novel agents have also shown intriguing outcomes as single agents (sunitinib) or in combination (bevacizumab and erlotinib). The encouraging results and clinical information gathered in recent trials are generating important clinical questions regarding which patients to treat, how to accommodate concurrent cirrhosis, and which parameters to use to monitor efficacy and the potential benefit from therapy.

Lack of somatic ErbB2 tyrosine kinase domain mutations in hepatocellular carcinoma

AIM

Small molecules targeting the epidermal growth factor receptor (EGFR) intracellular tyrosine kinase domain have shown promising activity in cancer therapeutics. Recent reports suggest activity of erlotinib, an ErbB1 inhibitor, and lapatinib, a dual inhibitor of ErbB1 and ErbB2, in hepatocellular carcinoma (HCC). Activating ErbB1 somatic mutations may predict treatment responses.

METHOD AND RESULTS

We have previously reported ErbB1 tyrosine kinase domain mutations to be rare or absent in HCC, but data on the frequency of ErbB2 tyrosine kinase domain mutations in HCC is currently limited, apart from reports of a missense mutation identified in 11% of a small Caucasian sample. We studied exons 18-23 of the ErbB2 gene from tumor DNA of 100 Asian human HCC and found no exonic mutations of potential significance.

CONCLUSION

Alternative mechanisms may be responsible for the observed therapeutic efficacy of ErbB1 and ErbB2 tyrosine kinase inhibitors.

Gemcitabine plus oxaliplatin (GEMOX) combined with cetuximab in patients with progressive advanced stage hepatocellular carcinoma: results of a multicenter phase 2 study

BACKGROUND

The authors conducted a phase 2 trial of the antiepidermal growth factor receptor (EGFR) monoclonal antibody cetuximab in combination with the gemcitabine plus oxaliplatin (GEMOX) regimen in patients with documented progressive hepatocellular carcinoma (HCC).

METHODS

Forty-five untreated patients with advanced-stage progressive HCC were prospectively enrolled. Treatment consisted of cetuximab at a dose of 400 mg/m2 initially then 250 mg/m2 weekly, plus gemcitabine at a dose of 1000 mg/m2 on Day 1 and oxaliplatin at a dose of 100 mg/m2 on Day 2, every 2 weeks. Treatment was continued until disease progression, unacceptable toxicity, or patient refusal.

RESULTS

Overall, 306 cycles were administered. Grade 3 to 4 hematologic toxicity consisted of thrombocytopenia (24%), neutropenia (20%), and anemia (4%). Grade 3 oxaliplatin-induced neurotoxicity occurred in 5 patients (11%) and grade 3 cutaneous toxicity in 7 patients (16%). There were no treatment-related deaths. The confirmed response rate was 20% and disease stabilization was obtained in 40% of patients. The median progression-free and overall survival times were 4.7 months and 9.5 months, respectively. The 1-year survival rate was 40%.

CONCLUSIONS

In poor-prognosis patients with progressive advanced-stage HCC, the GEMOX-cetuximab combination appears to be active and to have manageable toxicity. A comparative randomized trial is now being planned.

Development of sorafenib and other molecularly targeted agents in hepatocellular carcinoma

It is well appreciated that hepatocellular carcinoma (HCC) represents one of the most challenging malignancies of worldwide importance. In fact, HCC is the fifth most common cancer and the third most common cause of cancer-related death globally. The incidence rates for HCC in the U.S. and Western Europe have been rising. Unresectable or metastatic HCC carries a poor prognosis, and systemic therapy with cytotoxic agents provides marginal benefit. Because of the poor track record of systemic therapy in HCC, there has been a sense of nihilism for this disease in the oncology community for decades. However, with the arrival of newly developed, molecularly targeted agents and the success of some of these agents in other traditionally challenging cancers, such as renal cell carcinoma, there has been renewed interest in developing novel systemic therapy in HCC. At the recent Annual Meeting of the American Society of Clinical Oncology, results of a phase 3, randomized, placebo-controlled trial were presented in which sorafenib demonstrated improved survival in patients with advanced HCC. This landmark study represents the first agent that has demonstrated an improved overall survival benefit in this disease and sets the new standard for first-line treatment of advanced HCC. For this review, the author concisely summarized the current status of molecularly targeted agents that are under clinical development in advanced HCC.

Capecitabine plus oxaliplatin as first-line treatment in patients with advanced biliary system adenocarcinoma: a prospective multicentre phase II trial

This prospective multicentre phase II study characterises the toxicity and activity of first-line capecitabine and oxaliplatin combination therapy (CAPOX) in advanced biliary system adenocarcinomas. Patients received oxaliplatin (130 mg m⁻², day 1) plus capecitabine (1000 mg m⁻² b.i.d., days 1–14) every 3 weeks. Patients were stratified prospectively into two groups based on location of the primary (gallbladder carcinoma (GBC) or extrahepatic cholangiocarcinoma (ECC) versus intrahepatic mass-forming type cholangiocarcinoma (ICC)). Sixty-five patients were evaluable. The response rate in 47 patients with GBC/ECC was 27% (4% complete responses), and in 23 patients (49%) stable disease (SD) was encountered. In 18 patients with ICC, we observed no objective responses, but 6 patients (33%) had SD. Median survival was 12.8 months (95% CI, 10.0–15.6) for patients with GBC or ECC (GBC: 8.2 months; 95% CI, 4.3–11.7; ECC: 16.8 months; 95% CI, 12.7–20.5), and 5.2 months (95% CI, 0.6–9.8) for ICC patients. In both cohorts, therapy was well tolerated. The most common grade 3–4 toxicity was peripheral sensory neuropathy (11 patients). Our data suggest that the CAPOX regimen is a well-tolerated and active treatment option for advanced ECC and GBC but might produce poorer results for ICC.

Phase 2 study of cetuximab in patients with advanced hepatocellular carcinoma

BACKGROUND

Epidermal growth factor receptor (EGFR) and ligand expression is frequently seen in hepatocellular carcinoma (HCC). A phase 2 study was performed with cetuximab, a chimeric monoclonal antibody that binds specifically to EGFR, in patients with advanced HCC.

METHODS

Eligibility criteria included unresectable or metastatic measurable HCC, an Eastern Cooperative Oncology Group performance status <or=2, Cancer of the Liver Italian Program (CLIP) score <or=3, and adequate organ functions. The initial dose of cetuximab was 400 mg/m(2) given intravenously followed by weekly intravenous infusions at 250 mg/m(2). Each cycle was defined as 6 consecutive weekly treatments. EGFR expression was assayed by immunohistochemistry and trough serum concentrations of cetuximab were determined during the first cycle.

RESULTS

Thirty patients were enrolled and assessable for efficacy and toxicity. No responses were seen. Five patients had stable disease (median time, 4.2 months; range, 2.8-4.2 months). The median overall survival was 9.6 months (95% confidence interval [CI], 4.3-12.1 months) and the median progression-free survival (PFS) was 1.4 months (95% CI, 1.2-2.6 months). The treatment was generally well tolerated. No treatment-related grade 4-5 toxicities occurred. Grade 3 (according to the National Cancer Institute's Common Terminology Criteria for Adverse Events [version 3.0]) aspartate aminotransferase, hypomagnesemia, and fever without neutropenia were noted in 1 patient (3.3%) each. On Week 6 of Cycle 1, arithmetic mean serum cetuximab concentrations for patients with Child-Turcotte-Pugh (CTP) A and CTP B disease were 47.6 mcg/mL and 66.9 mcg/mL, respectively.

CONCLUSIONS

Although cetuximab could be safely administered with tolerable toxicity profiles, it demonstrated no antitumor activity in HCC in this phase 2 study. Cetuximab trough concentrations were not notably altered in patients with mild to moderate hepatic dysfunction.

Lapatinib: a tyrosine kinase inhibitor with a clinical role in breast cancer

Lapatinib is a dual (ErbB-1 and ErB-2) receptor tyrosine kinase inhibitor (TKI) that was recently approved by the FDA for the treatment of advanced breast cancer. It shows synergy with trastuzumab, and has demonstrated clinical activity in trastuzumab-resistant tumour. This paper reviews the drug development of lapatinib from preclinical studies to the pivotal Phase III trial and ongoing clinical studies. Areas of interest include the advantages of small molecule TKIs versus antibodies in targeting HER receptors and the efficacy of lapatinib in the treatment of cerebral metastases. The surprisingly high response rate in inflammatory breast cancer raises the possibility of other novel predictive biomarkers. The potential for combination and sequencing with other biological and cytotoxic agents is both exciting and challenging.

Lapatinib: a dual inhibitor of EGFR and HER2 tyrosine kinase activity

Lapatinib (GW 572016) is an oral inhibitor of the tyrosine kinase activity of epidermal growth factor receptor (EGFR) and human EGFR-2 (HER2), which are both frequently altered in human malignant tumors. Being a multitargeting agent, it has the theoretical ability to provide more efficient antitumor activity and delay the onset of tumor resistance. Based on promising preclinical results, lapatinib is being extensively studied in cancer patients. In Phase I clinical trials, the side effect profile of lapatinib results are favorable, with a few patients experiencing serious toxicity. Phase II studies showed that lapatinib has meaningful clinical activity in the setting of HER2-positive advanced breast cancer patients. Unfortunately, its activity in epidermal growth factor receptor-dominated cancers, such as colorectal cancer or squamous cell carcinoma of the head and neck, is modest. An extensive program is now ongoing in breast cancer patients to establish the correct role of lapatinib in this clinical setting. Studies in breast cancer, as well as in other solid tumors are also collecting a large amount of biological data. Correlative studies will hopefully clarify predictive factors of lapatinib efficacy that can be applied in clinical practice in order to select patients for treatment.