This Week in JAMA FREE

Excess body weight has been implicated as a risk factor for pancreatic cancer. To assess the associations between body mass index (BMI) over an individual's lifetime and pancreatic cancer risk, age at cancer onset, and overall survival, Li and colleagues Article analyzed data from a hospital-based case-control study that included 841 patients with pancreatic ductal adenocarcinoma and 754 healthy individuals. The authors found that overweight or obesity during early adulthood was associated with an increased risk of pancreatic cancer that was independent of diabetes status and with younger age at diagnosis. Obesity at an older age or shortly before diagnosis was associated with reduced overall survival regardless of disease stage or tumor resection status. In an editorial, McWilliams and Petersen Article discuss the implications of these relationships for the prevention and treatment of pancreatic cancer.

There is some evidence that migraine attacks may be associated with pathological changes in the brain seen on magnetic resonance imaging (MRI) scans. In an analysis of data from a population-based study of residents of Reykjavik, Iceland, Scher and colleagues Article examined whether individuals who reported monthly migraine symptoms in midlife were at increased risk of having infarct-like lesions (“infarcts”) identified on MRI that was performed an average 25 years later. The authors report that compared with individuals who did not have headaches once or more per month in midlife, women who reported having headache with aura had an increased prevalence of cerebellar infarcts on MRI. In an editorial, Kurth and Tzourio Article discuss what is known about migraine and brain infarcts and elaborate on the clinical significance of the reported associations.

Patients with prolongation of the electrocardiographic PR interval—termed first-degree atrioventricular (AV) block when the PR interval exceeds 200 milliseconds—are commonly encountered in clinical practice. Cheng and colleagues analyzed data from participants in the Framingham Heart Study to determine the clinical significance of first-degree AV block in ambulatory individuals. The authors found that compared with individuals with a normal PR interval, participants with first-degree AV block on an electrocardiogram obtained in the years 1968-1974 were at significantly increased risk of atrial fibrillation, pacemaker implantation, and death during long-term follow-up.

2009 marks the 100th anniversary of the identification of Pneumocystis, which is an important pathogen in immunocompromised patients. In a discussion of the case of a middle-aged man with chronic lymphocytic leukemia in partial remission who died from Pneumocystis pneumonia, Kovacs and Masur review the epidemiology, prevention, diagnosis, and treatment of Pneumocystis.

“During all the years of medical school, residency, and fellowship, one learns to care for the physical, mental, and now, perhaps, spiritual needs of the patient, but little of the world of business.” From “Minutes From Fishing and the Opera.”

The American Urological Association says that screening for prostate cancer should be offered to asymptomatic men at age 40 years, but other groups question whether there is sufficient evidence to support this recommendation.

Tuberculosis, the immune response, and obesity

A Cooperative Extension Service model for primary care

Join Charles M. Morin, PhD, Wednesday, July 15, from 2 to 3 PM eastern time to discuss cognitive behavioral therapy alone or with medication to treat persistent insomnia. Register at http://www.ihi.org/AuthorintheRoom. Send questions to replies@jama-archives.org.

How would you manage a 70-year-old woman with shingles? Go to www.jama.com to read the case, and submit your response, which may be selected for online publication. Submission deadline is June 28.

For your patients: Information about migraine headache.