CHICAGO—MRI is more accurate for detecting breast cancer than mammography, ultrasound or clinical breast examination alone, in women who carry the BRCA1 or BRCA2 gene mutation, according to a study in the September 15 issue of JAMA.

Women with BRCA1 and BRCA2 mutations who do not undergo prophylactic surgery have a lifetime risk of breast cancer of up to 85 percent, with a significantly higher risk of breast cancer than the general population from age 25 years onward, according to background information in the article. Current recommendations for women who have a BRCA1 or BRCA2 mutation are to undergo breast surveillance from age 25 years onward with mammography annually and clinical breast examination (CBE) every 6 months; however, many tumors are detected at a relatively advanced stage. Magnetic resonance imaging (MRI) and ultrasound may improve the ability to detect breast cancer at an early stage.

Ellen Warner, M.D., of Toronto-Sunnybrook Regional Cancer Centre, Toronto, Ontario, Canada, and colleagues compared the sensitivity and specificity of four methods of breast cancer surveillance (mammography, ultrasound, MRI, and CBE) in women with hereditary susceptibility to breast cancer due to a BRCA1 or BRCA2 mutation.

The study included 236 women aged 25 to 65 years with BRCA1 or BRCA2 mutations who underwent 1 to 3 annual screening examinations, consisting of MRI, mammography, and ultrasound at a teaching hospital between November 1997 and March 2003. On the day of imaging and at 6-month intervals, CBE was performed.

During the study period, there were 22 cancers detected (16 invasive and 6 ductal carcinoma in situ). Of these, 17 (77 percent) were detected by MRI vs. 8 (36 percent) by mammography, 7 (33 percent) by ultrasound, and 2 (9.1 percent) by CBE. All 4 screening modalities combined had a sensitivity of 95 percent vs. 45 percent for mammography and CBE combined.

CHICAGO—Patients who take beta-blocker medications appear to have a reduced risk for bone fractures, according to a study in the September 15 issue of JAMA.

According to background information in the article, animal studies have suggested that the beta-blocker propranolol increases bone formation, but data are limited on any associated reduced risk of fracture in humans.

Raymond G. Schlienger, Ph.D., M.P.H., of the University of Basel, Switzerland, and colleagues examined the association between beta-blocker use, with or without use of thiazide diuretics, and bone fracture risk in men and women aged 30 to 79 years. Researchers analyzed data from the UK General Practice Research Database (GPRD). The study included 30,601 patients with a new fracture diagnosis between 1993 and 1999 and 120,819 controls, matched to cases on age and sex and other factors.

The researchers found that compared with patients who did not use either beta-blockers or thiazide diuretics, patients who used only beta-blockers (3 or more prescriptions, about six months or longer) had a 23 percent lower risk for fracture, a 20 percent lower risk for fracture with use of thiazides only (3 or more prescriptions), and for combined use of beta-blockers and thiazides, a 29 percent lower risk.

CHICAGO—The estimated number of influenza-associated hospitalizations among elderly patients has increased substantially over the past two decades, according to an article in the September 15 issue of JAMA.

Although national estimates of influenza-associated deaths have been important in understanding the epidemiology of influenza over time and in planning for future epidemics and pandemics, "mortality incompletely reflects the severity of influenza infections because many severe illnesses do not result in death," according to background information in the article.

William W. Thompson, Ph.D., of the Centers for Disease Control and Prevention, Atlanta, and colleagues estimated the annual average number of hospitalizations associated with the circulation of the influenza virus over two decades. The researchers used data from the National Hospital Discharge Survey (NHDS) and World Health Organization Collaborating Laboratories to make estimates for the influenza seasons during 1979 - 1980 through 2000 - 2001.

The researchers analyzed hospitalizations in several different ways and found there were 226,054 primary and 294,128 any listed respiratory and circulatory hospitalizations associated with influenza virus infections on average each season (and annual averages of 94,735 primary and 133,900 any listed pneumonia and influenza hospitalizations associated with the influenza virus infections). Highest rates of influenza-associated primary respiratory and circulatory hospitalizations were found in persons 85 years and older.

After adjusting for length of each influenza season, influenza-associated rates of primary pneumonia and influenza hospitalizations increased over time among elderly. There were no significant increases in the rates of influenza-associated primary respiratory and circulatory hospitalizations after adjusting for the length of the influenza season. Children younger than five years had rates similar to those found among the 50 through 64 year-old age group. Persons aged five years through 49 years had the lowest rates of hospitalizations associated with influenza.

The authors write: "Currently, we estimate that more than 200,000 respiratory and circulatory hospitalizations are associated with influenza each year in the United States, substantially more than estimates of pneumonia and influenza hospitalizations."

ANNUAL NUMBER OF FLU-RELATED HOSPITALIZATIONS IN THE U.S. HIGHER THAN PREVIOUSLY ESTIMATED