Multi-Institutional Randomized Phase II Trial of Gefitinib for Previously Treated Patients With Advanced Non-Small-Cell Lung Cancer.

PURPOSE: To evaluate the efficacy and tolerability of two doses of gefitinib (Iressa [ZD1839]; AstraZeneca, Wilmington, DE), a novel epidermal growth factor receptor tyrosine kinase inhibitor, in patients with pretreated advanced non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: This was a randomized, double-blind, parallel-group, multicenter phase II trial. Two hundred ten patients with advanced NSCLC who were previously treated with one or two chemotherapy regimens (at least one containing platinum) were randomized to receive either 250-mg or 500-mg oral doses of gefitinib once daily. RESULTS: Efficacy was similar for the 250- and 500-mg/d groups. Objective tumor response rates were 18.4% (95% confidence interval [CI], 11.5 to 27.3) and 19.0% (95% CI, 12.1 to 27.9); among evaluable patients, symptom improvement rates were 40.3% (95% CI, 28.5 to 53.0) and 37.0% (95% CI, 26.0 to 49.1); median progression-free survival times were 2.7 and 2.8 months; and median overall survival times were 7.6 and 8.0 months, respectively. Symptom improvements were recorded for 69.2% (250 mg/d) and 85.7% (500 mg/d) of patients with a tumor response. Adverse events (AEs) at both dose levels were generally mild (grade 1 or 2) and consisted mainly of skin reactions and diarrhea. Drug-related toxicities were more frequent in the higher-dose group. Withdrawal due to drug-related AEs was 1.9% and 9.4% for patients receiving gefitinib 250 and 500 mg/d, respectively. CONCLUSION: Gefitinib showed clinically meaningful antitumor activity and provided symptom relief as second- and third-line treatment in these patients. At 250 mg/d, gefitinib had a favorable AE profile. Gefitinib 250 mg/d is an important, novel treatment option for patients with pretreated advanced NSCLC.

Trial Reporting in Immuno-Oncology (TRIO): An American Society of Clinical Oncology-Society for Immunotherapy of Cancer Statement.

PURPOSE: To develop recommendations for clinical trial reporting that address the unique efficacy, toxicity, and combination and sequencing aspects of immuno-oncology (IO) treatments. METHODS: ASCO and the Society for Immunotherapy of Cancer (SITC) convened a working group that consisted of practicing medical oncologists, immunologists, clinical researchers, biostatisticians, and representatives from industry and government to develop Trial Reporting in Immuno-Oncology (TRIO) recommendations. These recommendations are based on expert consensus, given that existing data to support evidence-based recommendations are limited. CONCLUSION: The TRIO recommendations are intended to improve the reporting of IO clinical trials and thus provide more complete evidence on the relative benefits and risks of an IO therapeutic approach. Given the rapid expansion of the number of IO clinical trials and ongoing improvements to the evidence base supporting the use of IO treatments in clinical care, these recommendations will likely need regular revision as the IO field develops.

Trial Reporting in Immuno-Oncology (TRIO): an American society of clinical oncology-society for immunotherapy of cancer statement.

PURPOSE: To develop recommendations for clinical trial reporting that address the unique efficacy, toxicity, and combination and sequencing aspects of immuno-oncology (IO) treatments. METHODS: ASCO and the Society for Immunotherapy of Cancer (SITC) convened a working group that consisted of practicing medical oncologists, immunologists, clinical researchers, biostatisticians, and representatives from industry and government to develop Trial Reporting in Immuno-Oncology (TRIO) recommendations. These recommendations are based on expert consensus, given that existing data to support evidence-based recommendations are limited. CONCLUSION: The TRIO recommendations are intended to improve the reporting of IO clinical trials and thus provide more complete evidence on the relative benefits and risks of an IO therapeutic approach. Given the rapid expansion of the number of IO clinical trials and ongoing improvements to the evidence base supporting the use of IO treatments in clinical care, these recommendations will likely need regular revision as the IO field develops.

Selective oral epidermal growth factor receptor tyrosine kinase inhibitor ZD1839 is generally well-tolerated and has activity in non-small-cell lung cancer and other solid tumors: results of a phase I trial.

PURPOSE: To investigate safety, tolerability, dose-related pharmacologic properties, and pharmacodynamics of ZD1839 (gefinitib, Iressa; AstraZeneca Pharmacueticals, Wilmington, DE), an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, in patients with solid tumor types known to express or highly express EGFR. METHODS: This was an open-label, phase I, dose escalation safety/tolerability trial of oral ZD1839 (150 to 1,000 mg/d), administered once daily for 28-continuous-day cycles until disease progression or undue toxicity. RESULTS: Of 71 (69 assessable for safety; 58 for efficacy) patients at seven dose levels, most had non-small-cell lung (n = 39) or head and neck (n = 18) cancer, and 68 of 71 patients received prior cancer therapy (two or more regimens in 54 patients [78%]). Diarrhea and rash, the primary dose-limiting toxicities (DLTs), occurred at 800 mg. Frequent treatment-related grade 1/2 adverse events were diarrhea (55%), asthenia (44%), and acne-like follicular rash (46%). At doses >or= 800 mg, 45% of patients required dose reductions. No increased or cumulative toxicity was observed over 250 patient-months of exposure. Pharmacokinetic analysis showed that steady-state occurred by day 7, interpatient exposure was more variable than intrapatient exposure, and variability of exposure did not change with dose. One patient experienced a partial response, but antitumor activity manifested mainly as prolonged stable disease (45% of patients >or= 3 months, 22% >or= 6 months, and 7.2% >or= 1 year). No relationship between dose, response, or duration on study was observed. CONCLUSION: Rash and diarrhea, generally mild and tolerable at doses

Gefitinib in combination with gemcitabine and cisplatin in advanced non-small-cell lung cancer: a phase III trial--INTACT 1.

PURPOSE: The purpose of this study was to determine whether the addition of the epidermal growth factor receptor tyrosine kinase inhibitor gefitinib (Iressa, ZD1839; AstraZeneca, Wilmington, DE) to standard first-line gemcitabine and cisplatin provides clinical benefit over gemcitabine and cisplatin alone in patients with advanced or metastatic non-small-cell lung cancer (NSCLC). Gefitinib has demonstrated encouraging efficacy in advanced NSCLC in phase II trials in pretreated patients, and a phase I trial of gefitinib in combination with gemcitabine and cisplatin showed favorable tolerability. PATIENTS AND METHODS: This was a phase III randomized, double-blind, placebo-controlled, multicenter trial in chemotherapy-naive patients with unresectable stage III or IV NSCLC. All patients received up to six cycles of chemotherapy (cisplatin 80 mg/m(2) on day 1 and gemcitabine 1,250 mg/m(2) on days 1 and 8 of the 3-week cycle) plus either gefitinib 500 mg/d, gefitinib 250 mg/d, or placebo. Daily gefitinib or placebo was continued until disease progression. End points included overall survival (primary), time to progression, response rates, and safety evaluation. RESULTS: A total of 1,093 patients were enrolled. There was no difference in efficacy end points between the treatment groups: for the gefitinib 500 mg/d, gefitinib 250 mg/d, and placebo groups, respectively, median survival times were 9.9, 9.9, and 10.9 months (global ordered log-rank [GOLrank] P =.4560), median times to progression were 5.5, 5.8, and 6.0 months (GOLrank; P =.7633), and response rates were 49.7%, 50.3%, and 44.8%. No significant unexpected adverse events were seen. CONCLUSION: Gefitinib in combination with gemcitabine and cisplatin in chemotherapy-naive patients with advanced NSCLC did not have improved efficacy over gemcitabine and cisplatin alone. The reasons for this remain obscure and require further preclinical testing.

Gefitinib in combination with paclitaxel and carboplatin in advanced non-small-cell lung cancer: a phase III trial--INTACT 2.

PURPOSE: Preclinical studies indicate that gefitinib (Iressa, ZD1839; AstraZeneca, Wilmington, DE), an orally active epidermal growth factor receptor tyrosine kinase inhibitor, may enhance antitumor efficacy of cytotoxics, and combination with paclitaxel and carboplatin had acceptable tolerability in a phase I trial. Gefitinib monotherapy demonstrated unparalleled antitumor activity for a biologic agent, with less toxicity than docetaxel, in phase II trials in refractory, advanced non-small-cell lung cancer (NSCLC). This phase III, randomized, placebo-controlled, double-blind trial evaluated gefitinib plus paclitaxel and carboplatin in chemotherapy-naive patients with advanced NSCLC. PATIENTS AND METHODS: Patients received paclitaxel 225 mg/m(2) and carboplatin area under concentration/time curve of 6 mg/min/mL (day 1 every 3 weeks) plus gefitinib 500 mg/d, gefitinib 250 mg/d, or placebo. After a maximum of six cycles, daily gefitinib or placebo continued until disease progression. End points included overall survival, time to progression (TTP), response rate (RR), and safety evaluation. Results A total of 1,037 patients were recruited. Baseline demographic characteristics were well balanced. There was no difference in overall survival (median, 8.7, 9.8, and 9.9 months for gefitinib 500 mg/d, 250 mg/d, and placebo, respectively; P =.64), TTP, or RR between arms. Expected dose-related diarrhea and skin toxicity were observed in gefitinib-treated patients, with no new significant/unexpected safety findings from combination with chemotherapy. Subset analysis of patients with adenocarcinoma who received > or = 90 days' chemotherapy demonstrated statistically significant prolonged survival, suggesting a gefitinib maintenance effect. CONCLUSION: Gefitinib showed no added benefit in survival, TTP, or RR compared with standard chemotherapy alone. This large, placebo-controlled trial confirmed the favorable gefitinib safety profile observed in phase I and II monotherapy trials.

Multi-institutional randomized phase II trial of gefitinib for previously treated patients with advanced non-small-cell lung cancer (The IDEAL 1 Trial) [corrected].

PURPOSE: To evaluate the efficacy and tolerability of two doses of gefitinib (Iressa [ZD1839]; AstraZeneca, Wilmington, DE), a novel epidermal growth factor receptor tyrosine kinase inhibitor, in patients with pretreated advanced non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: This was a randomized, double-blind, parallel-group, multicenter phase II trial. Two hundred ten patients with advanced NSCLC who were previously treated with one or two chemotherapy regimens (at least one containing platinum) were randomly assigned to receive either 250-mg or 500-mg oral doses of gefitinib once daily. RESULTS: Efficacy was similar for the 250- and 500-mg/d groups. Objective tumor response rates were 18.4% (95% confidence interval [CI], 11.5 to 27.3) and 19.0% (95% CI, 12.1 to 27.9); among evaluable patients, symptom improvement rates were 40.3% (95% CI, 28.5 to 53.0) and 37.0% (95% CI, 26.0 to 49.1); median progression-free survival times were 2.7 and 2.8 months; and median overall survival times were 7.6 and 8.0 months, respectively. Symptom improvements were recorded for 69.2% (250 mg/d) and 85.7% (500 mg/d) of patients with a tumor response. Adverse events (AEs) at both dose levels were generally mild (grade 1 or 2) and consisted mainly of skin reactions and diarrhea. Drug-related toxicities were more frequent in the higher-dose group. Withdrawal due to drug-related AEs was 1.9% and 9.4% for patients receiving gefitinib 250 and 500 mg/d, respectively. CONCLUSION: Gefitinib showed clinically meaningful antitumor activity and provided symptom relief as second- and third-line treatment in these patients. At 250 mg/d, gefitinib had a favorable AE profile. Gefitinib 250 mg/d is an important, novel treatment option for patients with pretreated advanced NSCLC [corrected]

Development of the novel biologically targeted anticancer agent gefitinib: determining the optimum dose for clinical efficacy.

The emergence of novel, biologically targeted anticancer agents such as gefitinib ('Iressa', ZD1839) has raised the question of how the dose for later-stage clinical development and clinical use is best determined. For cytotoxic drugs, because toxic effects and antitumor activity often fall within the same dose range and are dose dependent, the clinically used dose will depend on the therapeutic window. Therefore, the maximum tolerated dose identified in Phase I trials is typically used to determine the dose level for Phase II and III trials. However, because biologically targeted agents are expected to provide clinical benefits that are not predicted by surrogate end points of toxicity to normal replicating tissue, new Phase I trials have been designed to determine the optimum biological dose for use in further studies. A large, multifaceted Phase I program was designed to evaluate the pharmacokinetics, safety, efficacy, and targeted biological activity of a once-daily oral dose of gefitinib. The maximum tolerated dose was >or=700 mg/day, although doses as low as 150 mg/day provided (a). plasma concentrations sufficient for pharmacological activity, (b). evidence of targeted biological effect, and (c). antitumor activity. From these observations, two large Phase II trials ('Iressa' Dose Evaluation in Advanced Lung Cancer 1 and 2) evaluated 250- and 500-mg/day doses of gefitinib in patients with advanced non-small cell lung cancer (NSCLC). As predicted from the Phase I trials, doses >250 mg/day provided no additional efficacy benefit, whereas adverse effects increased in a dose-dependent manner. Consequently, the recommended dose of gefitinib in NSCLC is 250 mg/day. The early clinical trial development of gefitinib provides a model for the development of novel, noncytotoxic anticancer agents.

Improvements in quality of life and disease-related symptoms in phase I trials of the selective oral epidermal growth factor receptor tyrosine kinase inhibitor ZD1839 in non-small cell lung cancer and other solid tumors.

PURPOSE: The feasibility and utility of assessing quality of life (QoL) and disease-related symptoms in patients with advanced cancer have been evaluated in two Phase I clinical trials of p.o. administered ZD1839 ('Iressa'), an epidermal growth factor receptor tyrosine kinase inhibitor, in patients with advanced cancer. EXPERIMENTAL DESIGN: Functional Assessment of Cancer Therapy (FACT) questionnaires, including disease-specific subscales for lung, head and neck, colorectal, prostate, and ovarian cancer, were completed by patients in two open-label, Phase I, escalating multiple-dose safety and tolerability trials. RESULTS: In 157 patients, 92% of whom had received prior therapy, compliance in returning FACT questionnaires was 87% (European/Australian trial) and 57% (United States trial). This did not appear to be influenced by dose level or tumor type. For patients with colorectal, prostate, or ovarian cancer, median QoL [FACT and Trial Outcome Index (TOI)] scores deteriorated over time. In contrast, for patients with non-small cell lung cancer (NSCLC) or head and neck cancer, median FACT and TOI scores did not deteriorate significantly, and in the United States trial, head and neck cancer scores improved significantly over time. In patients with NSCLC, symptom-related scores measured by the Lung Cancer Subscale of FACT-L appeared sensitive to clinical change. CONCLUSIONS: QoL (FACT-L) questionnaires were used successfully in the Phase I clinical trials of ZD1839. They appeared to be a sensitive tool to monitor clinical changes for the five tumor types in these trials and showed that ZD1839 has the potential to improve patients' QoL.

Gefitinib: phase II and III results in advanced non-small cell lung cancer.

Several novel biologic agents have been designed to specifically inhibit different aspects of tumor growth and progression. The epidermal growth factor receptor has a pivotal role in tumor biology and thus is an important anticancer target. Gefitinib is an orally active epidermal growth factor receptor tyrosine kinase inhibitor that blocks signal-transduction pathways implicated in the proliferation and survival of cancer cells. Clinically meaningful antitumor activity, symptom relief, and a good tolerability profile have been shown in phase II trials of gefitinib monotherapy in patients with recurrent non-small cell lung cancer. Clinical trials are ongoing to investigate further applications of this novel agent for the treatment of non-small cell lung cancer.

The impact of gefitinib on epidermal growth factor receptor signaling pathways in cancer.

The ErbB family of receptor tyrosine kinases, of which the epidermal growth factor receptor (EGFR) is the prototype, is associated with the formation and malignant progression of most of the common solid tumors. These molecules play a key role in a complex network of signal transduction pathways that function in normal development as well as in neoplastic transformation. The EGFR and other family members are therefore promising targets for new anticancer therapies. In normal tissues, EGFR-tyrosine kinase (TK) activity is strictly controlled. However, in tumor cells, there are multiple mechanisms that can lead to increased or inappropriate EGFR-TK activity, including altered expression of EGFR, its ligand, or interacting molecules; decreased deactivation through phosphatases or downregulation; or mutation of the EGFR protein. Novel therapeutic approaches aimed at inhibiting increased EGFR-TK activity include antibodies that block the extracellular ligand-binding site, antibody or ligand fusion proteins that specifically target toxins to the tumor cells, or small-molecule TK inhibitors (TKIs) that act intracellularly to block downstream signal transduction from EGFR. Studies have shown that such blockade can lead to reduced cellular proliferation, inhibition of survival signals, and inhibition of tumor metastasis and angiogenesis. Additionally, some agents, including EGFR antibodies and TKIs such as gefitinib have been demonstrated to be effective against various human solid tumors in preclinical models and have shown activity in advanced non-small-cell lung cancer and other solid tumors.

Distribution and function of EGFR in human tissue and the effect of EGFR tyrosine kinase inhibition.

From immunohistochemical and ligand-binding studies, it is known that the epidermal growth factor receptor (EGFR), a member of the erbB family of receptors, is expressed in tissues of epithelial, mesenchymal and neuronal origin and plays a major role in normal cellular processes such as proliferation, differentiation and development. EGFR is highly expressed in a number of solid tumours and its expression correlates with tumour progression, resistance to chemotherapy and a poor prognosis; it is consequently an attractive target for the rational design of novel anticancer agents. Knowledge of the role of EGFR in normal tissues will help the understanding of the adverse events associated with such agents. Studies in knockout mice and preclinical toxicology studies have shown that the major effects of inhibiting the EGFR are skin and gastrointestinal toxicities. Clinical studies with inhibitors of EGFR, such as gefitinib, cetuximab and erlotinib, have shown a favourable adverse-event profile, primarily consisting of skin and gastrointestinal toxicities, as predicted from the mechanism-based effects observed in preclinical studies.

Efficacy of gefitinib, an inhibitor of the epidermal growth factor receptor tyrosine kinase, in symptomatic patients with non-small cell lung cancer: a randomized trial.

CONTEXT: More persons in the United States die from non-small cell lung cancer (NSCLC) than from breast, colorectal, and prostate cancer combined. In preclinical testing, oral gefitinib inhibited the growth of NSCLC tumors that express the epidermal growth factor receptor (EGFR), a mediator of cell signaling, and phase 1 trials have demonstrated that a fraction of patients with NSCLC progressing after chemotherapy experience both a decrease in lung cancer symptoms and radiographic tumor shrinkages with gefitinib. OBJECTIVE: To assess differences in symptomatic and radiographic response among patients with NSCLC receiving 250-mg and 500-mg daily doses of gefitinib. DESIGN, SETTING, AND PATIENTS: Double-blind, randomized phase 2 trial conducted from November 2000 to April 2001 in 30 US academic and community oncology centers. Patients (N = 221) had either stage IIIB or IV NSCLC for which they had received at least 2 chemotherapy regimens. INTERVENTION: Daily oral gefitinib, either 500 mg (administered as two 250-mg gefitinib tablets) or 250 mg (administered as one 250-mg gefitinib tablet and 1 matching placebo). MAIN OUTCOME MEASURES: Improvement of NSCLC symptoms (2-point or greater increase in score on the summed lung cancer subscale of the Functional Assessment of Cancer Therapy-Lung [FACT-L] instrument) and tumor regression (>50% decrease in lesion size on imaging studies). RESULTS: Of 221 patients enrolled, 216 received gefitinib as randomized. Symptoms of NSCLC improved in 43% (95% confidence interval [CI], 33%-53%) of patients receiving 250 mg of gefitinib and in 35% (95% CI, 26%-45%) of patients receiving 500 mg. These benefits were observed within 3 weeks in 75% of patients. Partial radiographic responses occurred in 12% (95% CI, 6%-20%) of individuals receiving 250 mg of gefitinib and in 9% (95% CI, 4%-16%) of those receiving 500 mg. Symptoms improved in 96% of patients with partial radiographic responses. The overall survival at 1 year was 25%. There were no significant differences between the 250-mg and 500-mg doses in rates of symptom improvement (P =.26), radiographic tumor regression (P =.51), and projected 1-year survival (P =.54). The 500-mg dose was associated more frequently with transient acne-like rash (P =.04) and diarrhea (P =.006). CONCLUSIONS: Gefitinib, a well-tolerated oral EGFR-tyrosine kinase inhibitor, improved disease-related symptoms and induced radiographic tumor regressions in patients with NSCLC persisting after chemotherapy.

Quantifying factors for the success of stratified medicine.

Co-developing a drug with a diagnostic to create a stratified medicine - a therapy that is targeted to a specific patient population on the basis of a clinical characteristic such as a biomarker that predicts treatment response - presents challenges for product developers, regulators, payers and physicians. With the aim of developing a shared framework and tools for addressing these challenges, here we present an analysis using data from case studies in oncology and Alzheimer's disease, coupled with integrated computational modelling of clinical outcomes and developer economic value, to quantify the effects of decisions related to key issues such as the design of clinical trials. This illustrates how such analyses can aid the coordination of diagnostic and drug development, and the selection of optimal development and commercialization strategies. It also illustrates the impact of the interplay of these factors on the economic feasibility of stratified medicine, which has important implications for public policy makers.

Making the investigational oncology pipeline more efficient and effective: are we headed in the right direction?

Advances in our knowledge of the molecular mechanisms involved in cancer biology have contributed to an increase in novel target-specific oncology therapeutics. Unfortunately, clinical development of new drugs is an expensive and slow process, and the patient and financial resources needed to study the vast number of potential therapies are limited, requiring novel approaches to clinical trial design and patient recruitment. In addition, traditional efficacy endpoints may not be adequate to fully determine the therapeutic worth of the new classes of targeted agents. In this new era of drug development, it has become increasingly clear that new clinical trial design paradigms that examine nontraditional endpoints have become necessary to assist in prioritizing the development of the most promising agents. It is also vital that individual patient management be considered, and the subpopulations of patients most likely to derive benefit or experience harm from a new therapy be identified as early as possible. Phase I and II clinical trials allow investigators doing clinical research the opportunity to define these critical endpoints and subpopulations early on, before conducting large-scale randomized phase III clinical trials, which require an abundance of financial and patient resources.

Translating clinical trials into meaningful outcomes.

Efforts to unravel the complex biology that is necessary to develop new therapies best suited for an individual with cancer are at a crossroads with a strained health care system and an insufficient clinical trial apparatus. The resulting failures have been described as the "valley of death." Progress into the future will require new considerations and the engagement of a broad band of stakeholders. To identify novel therapeutics that are likely to succeed in late development and to be meaningful for clinical practice, investigators will need to make a paradigm shift in designing clinical trials and endpoints while adhering to scientific rigor when interpreting results and making informed decisions. Large phase III trials that show a modest incremental benefit will continue to diminish in value for patients, clinicians, payers, and industry. Outcomes that are robust in both magnitude and application to the real world will take on increasing importance. Ensuring active participation by patients, lowering barriers to health care access, and protecting patients through health care reform are requirements for the future success of the cancer clinical research enterprise. The challenge today is to develop new approaches to translate scientific discovery into cost-effective and meaningful improvements in cancer outcomes.

Treatment of malignant pheochromocytoma/paraganglioma with cyclophosphamide, vincristine, and dacarbazine: recommendation from a 22-year follow-up of 18 patients.

BACKGROUND: A long-term follow-up was conducted of 18 patients with a diagnosis of pheochromocytoma/paraganglioma treated with a combination of cyclophosphamide, vincristine, and dacarbazine (CVD). METHODS: The study design was a nonrandomized, single-arm trial conducted at a government medical referral center. Eighteen patients with metastatic malignant pheochromocytoma/paraganglioma were studied. After controlling symptoms of catecholamine excess, patients were treated with cyclophosphamide at 750 mg/m(2), vincristine at 1.4 mg/m(2), and dacarbazine at 600 mg/m(2) on Day 1 and dacarbazine at 600 mg/m(2) on Day 2, every 21 to 28 days. RESULTS: Combination chemotherapy with CVD produced a complete response rate of 11% and a partial response rate of 44%. Median survival from a landmark was 3.8 years for patients whose tumors responded to therapy and 1.8 years for patients whose tumors did not respond (P = .65). All patients with tumors scored as responding reported improvement in their symptoms related to excessive catecholamine release and had objective improvements in blood pressure. CVD was well tolerated with only grade I/II toxicities. CONCLUSIONS: Combination chemotherapy with CVD produced objective tumor responses in patients with advanced malignant pheochromocytoma/paraganglioma. In this 22-year follow-up there was no difference in overall survival between patients whose tumors objectively shrank and those with stable or progressive disease. However, patients reported improvement in symptoms, had objective improvements in blood pressure, and had tumor shrinkage that made surgical resection possible. The authors conclude that CVD therapy is not indicated in every patient with metastatic pheochromocytoma/paraganglioma, but should be considered in the management of patients with symptoms and where tumor shrinkage might be beneficial.

Therapeutic potential of tyrosine kinase inhibitors in breast cancer.

Despite recent advances in the treatment of breast cancer, survival rates for patients with metastatic breast cancer remain poor, and new treatments are still required for both hormone-dependent and hormone-independent disease. The epidermal growth factor receptor (EGFR) is a promising new target for anticancer therapy because it is commonly highly expressed in breast cancer and is implicated in the control of many aspects of tumor biology. Because expression of EGFR is inversely related to expression of the estrogen receptor (ER) and is associated with resistance to currently available breast cancer therapies, EGFR-targeted therapies may be valuable in the treatment of ER-negative tumors and endocrine-resistant, ER-positive tumors. Furthermore, the novel mechanism of action of EGFR-targeted therapies may complement the antitumor activity of existing treatment with cytotoxic agents, radiotherapy, or hormones. In this article, the small-molecule inhibitors of the tyrosine kinase activity of EGFR are discussed, with particular emphasis on the potential use of such agents at each stage of breast cancer, including a potential role in chemoprevention.