Effect of insulin-like growth factor 1 receptor inhibitor on sensitization of head and neck cancer cells to cetuximab and methotrexate

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Background: Insulin-like growth factor 1 receptor (IGF1R) is highly expressed in head and neck squamous cell carcinoma (HNSCC) and IGF1R inhibitors have been shown to modulate sensitivity to selected chemotherapeutic agents and radiation. The combination effects of an IGF1R inhibitor, MK-0646, with cetuximab or cytotoxic agents that are commonly used in the treatment of recurrent and/or metastatic HNSCC were examined in cetuximab resistant and sensitive HNSCC cell lines. Methods: The cell lines, SCC1 and its cetuximab-resistant clone 1Cc8, were treated with MK-0646, cetuximab or methotrexate, and a combination of MK-0646 and each anti-cancer drug (MK-0646 was supplied by Merck & Co., Inc.). The effect of treatments on cell proliferation and anti-tumor activity was determined using MTS assay in vitro and in vivo using mouse xenografts generated from the cell lines. Overall changes in the gene and protein expressions with the treatments were determined by DNA microarrays and western blots. Results: The IGF1R inhibitor, MK-0646, showed high-sensitivity in vitro xenograft model in SCC1 as monotherapy and increased sensitivity to cetuximab in SCC1 and to methotrexate in 1Cc8 in combination. However, MK-0646 did not inhibit cell proliferation in vitro and in vivo in 1Cc8. The gene expression array and western blot analyses showed that MK-0646 decreased expression of AKT and dihydrofolate reductase (DHFR), a target of methotrexate. Increased expressions of AKT and DHFR have been shown to associate with cetuximab and methotrexate resistance as well as radiation resistance. Conclusions: The development of tolerance in response to the IGF1R inhibitor and cetuximab is common. Whereas IGF1R inhibitors may have little therapeutic impact in cetuximab resistant, the IGF1R inhibitor may modulate response to selected chemotherapeutic agents and to radiation. The IGF1R inhibitor appears to enhance cetuximab and methotrexate response, and modulates genes associated with radiation resistance thereby providing alternative regimens for recurrent and refractory HNSCC patients who have developed resistance to initial therapies.

No significant financial relationships to disclose.

Longitudinal oncology registry of head and neck carcinoma (LORHAN): First report of outcomes

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Background: Registries can be invaluable for describing patterns of care and outcomes for a population of patients (pts). We report the initial survival findings from LORHAN, a prospective, longitudinal, observational national registry of head and neck carcinoma (HNC) pts. Methods: Pts are eligible for LORHAN if they have newly diagnosed HNC, are scheduled to receive radiotherapy (RT) or drug therapy, are ≥18 years of age and have provided written informed consent. Data are entered in the registry electronically and transferred via Secure HTTP protocols. Patient confidentiality is strictly maintained. Pts are followed from time of initial diagnosis and for a minimum of 2 and up to 10 years. When information is complete and has been verified and signed off by the investigator, a record is locked. Only locked records are summarized and reported. Results: 2,354 pts have been enrolled in LORHAN since Dec. 2005. Of these, 1,326 pts have completed initial cancer treatment and have locked records. 1- and 2-year follow-up data are available for 583 and 56 pts, respectively. Baseline characteristics were similar between settings, except that pts treated at academic centers were significantly younger (58 vs. 62 years of age), had poorer performance status (mean Zubrod: 0.9 vs. 0.7), had fewer laryngeal tumors (17% vs. 27% of pts) but more oropharyngeal tumors (42% vs. 37% of pts) and presented with more advanced disease (stage IV: 70% vs. 48% of pts) compared to pts treated in community. Treatment did not differ by setting. Treatment and survival data are shown below. Conclusions: LORHAN demonstrates it is feasible to collect more detailed information about patient and tumor features and treatment other than surgery. Changes in the pattern of care and survival findings are expected to emerge as newer regimens, including IC and targeted agents, are incorporated more broadly into clinical practice, and data in LORHAN matures.

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EGFR-targeting monoclonal antibodies in head and neck cancer

The epidermal growth factor (EGFR) and its receptor were discovered nearly 40 years ago. Over the past decade interruption of this pathway has been exploited in the treatment of various solid tumors. Antibodies that interfere with ligand binding to and dimerization of the EGFR (and small molecules that inhibit the EGFR tyrosine kinase) are anti-proliferative, profoundly radiosensitizing, and synergistic with DNA-damaging cytotoxic agents. Proposed mechanisms of radio- and chemosensitization include enhanced apoptosis, interference with DNA repair and angiogenesis, receptor depletion from the cell surface and antibody-dependent cell-mediated cytotoxicity. This article provides a reader with a comprehensive review of EGFR-targeting antibodies under development for the treatment of head and neck squamous cell cancer (HNSCC) and also summarizes relevant clinical data in this disease with small molecule EGFR inhibitors. One of the monoclonal antibodies, cetuximab, recently received full FDA approval for the treatment of patients with locally advanced (with radiation) or metastatic HNSCC (as a single agent). Regulatory approval followed reporting of a large international study in which the addition of cetuximab to definitive radiation therapy in HNSCC resulted in statistically significant improvements in locoregional control and overall survival. Results of the pivotal trial, other clinical data supporting the regulatory approval, and a preview of the next generation of clinical trials are presented. Considerable work remains to be done, particularly to enhance our understanding of factors that may predict for favorable response to EGFR inhibitor therapy and to evaluate the impact of integrating anti-EGFR therapies into complex chemoradiation programs delivered with curative intent.

Longitudinal Oncology Registry of Head and Neck Carcinoma (LORHAN), a new national cancer registry

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Background: Registries can be invaluable for describing patterns of care for a population of patients (pts). Most cancer registries, however, do not possess sufficient breadth or depth to provide a complete and reliable picture of clinical practice. We report the launch of LORHAN, a new national registry of head and neck carcinoma (HNC) pts. LORHAN is designed to extend current cancer registries by providing detailed data on radiation and/or cancer drugs delivered to HNC pts in all practice settings. Methods: This is a prospective, multi-center, longitudinal, observational registry. Pts with newly diagnosed HNC, scheduled to receive radiotherapy or drug therapy, ≥18 years of age and providing written informed consent are being enrolled. Patients participating in clinical trials are eligible for LORHAN. The primary objective of the registry is to describe, in detail, patterns of care for HNC pts. The secondary objectives are to document outcome by treatment regimen, determine the incidence and severity of major toxicities and to identify supportive care received for managing treatment-related complications. Pts are entered in the registry from the time of initial diagnosis and are followed for at least 2 years and up to 10 years. Detailed information on initial treatment and re-treatment is collected. Data entry is electronic and incorporates encrypted point-to-point data transfer via secure HTTP protocols. Physician and patient confidentiality are strictly maintained. Participating practitioners can review and compare their data on a real-time basis to the database. Registry pts may be linked to the NDI to minimize lost to follow-up. Analyses of data are primarily descriptive. Results: LORHAN was launched in Oct. 2005, and as of Dec., 7 sites have received IRB approval and 3 pts have been enrolled. Of the 7 sites, 1 is an academic site and the remaining are community-based practices. An additional 21 sites (17 academic, 4 community) are at various stages of participation. More than 100 medical oncologists and radiation oncologists are anticipated to participate and approximately 26,000 pts will be eligible each year. Accrual status will be updated. Conclusions: LORHAN is a new national initiative that may further the understanding of the care of HNC pts across practice settings.

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