Gefitinib, an inhibitor of the tyrosine kinase of the epidermal growth factor receptor (EGFR), is effective in less than 20 percent of patients with non–small-cell lung cancer. In this study, most tumors from patients with a response to gefitinib had a mutation in the EGFR gene that alters the tyrosine kinase of EGFR.

The mechanism underlying the responsiveness to gefitinib of non–small-cell lung cancer, the leading cause of death from cancer in the United States, has broad implications for the treatment of this type of cancer and other solid tumors in which EGFR has a role.

Some patients with chronic heart failure have intraventricular conduction delays, which cause asynchronous contraction of the left ventricle. This large clinical trial confirmed that biventricular pacing to restore synchronous contraction has significant benefits in such patients. The addition of an implantable defibrillator further reduces mortality.

In patients with heart failure who have intraventricular conduction delays, resynchronization therapy may have clinical benefit, especially when combined with an implantable defibrillator.

Patients with left ventricular dysfunction due to nonischemic dilated cardiomyopathy are at substantial risk for sudden death from ventricular arrhythmias. This study found that prophylactic implantation of a cardioverter–defibrillator did not improve overall survival but significantly reduced the risk of death from cardiac arrhythmias.

Routine prophylactic use of cardioverter–defibrillators cannot be recommended for patients with left ventricular dysfunction due to nonischemic dilated cardiomyopathy. The implantation of such a device should be considered on a case-by-case basis.

A 55-year-old overweight woman presents with a three-month history of pain in her right inferior heel. The pain is worse on taking her first steps in the morning. The physical examination is normal except for nonspecific tenderness in the region of the medial calcaneal tubercle. How should the patient be evaluated and treated?

Rheumatoid arthritis affects about 1 percent of the U.S. population and can cause irreversible joint deformities and functional impairment. Although the cause of this autoimmune disease remains obscure, greater understanding of its underlying mechanisms has facilitated the development of new drugs and revolutionized treatment.

This Drug Therapy article reviews the properties, mechanisms, and use of several new drugs.

A 76-year-old woman was referred to the neurology clinic because of numbness and pain in her feet and legs. The symptoms began six years earlier. Imaging studies of the spine were unrevealing, and electrodiagnostic tests were normal. The differential diagnosis of painful sensory neuropathy is reviewed, and new diagnostic testing and treatment options are discussed.

In 2003, Medicare approved coverage for three new procedures: lung-volume–reduction surgery, implantation of cardioverter–defibrillators, and implantation of left ventricular assist devices. The annual cost to Medicare for these treatments could be as high as $11 billion, which is more than 20 percent of the expected annual cost of the Medicare drug benefit. Medicare's current policy is to pay for services that are "reasonable and necessary." The author argues that explicit criteria should be developed to guide Medicare's decisions about which procedures it will cover.