Other highlights in the December 15 JNCI

The accuracy of mammographic interpretation can vary widely, but the source of the variability has not been explained. To investigate the relationship between radiologists' characteristics and actual performance, William E. Barlow, Ph.D., of Cancer Research and Biostatistics in Seattle, and colleagues surveyed 124 radiologists and tracked cancer outcomes from the more than 460,000 screening mammograms they interpreted between 1996 and 2001.

Greater volume of mammograms interpreted and more years of experience were not associated with greater accuracy. However, greater volume was associated with higher sensitivity (more true positive results in women who had breast cancer) and lower specificity (more false positive results in women who did not have breast cancer) whereas more experience was associated with lower sensitivity and higher specificity. The authors conclude that increasing volume requirements for radiologists is unlikely to improve the interpretation of mammograms.

"Although radiologists differ in performance, accuracy does not appear to be simply attributable to years of experience or number of mammograms interpreted," the authors write. "Direct feedback of performance characteristics couple with training may be more helpful than experience without feedback. The most instructive exercise may be to have an open discussion of misjudged mammograms, but concern about malpractice claims may prevent this opportunity from occurring."

Contact: Joan DeClaire, Communications, Center for Health Studies, Group Health Cooperative, 206-287-2653, declaire@ghc.org

Levels of Sex Hormones May Be Associated With Increased Risk of Some Types of Breast Cancer, Study Finds

Circulating levels of several sex steroid hormones may be associated with an increased risk of estrogen receptor (ER)– and progesterone receptor (PR)–positive breast cancers, according to a new study.

Although hormone levels have been associated with the risk of breast cancer among postmenopausal women, few studies have examined their relationship with tumor receptor status or invasive versus in situ status. Stacey A. Missmer, of Brigham and Women's Hospital in Boston, and colleagues investigated these relations in a case–control study of nearly 1,000 women from the Nurses' Health Study.

The researchers found a direct association between breast cancer risk and the level of both estrogens and androgens but not the levels of progesterone or sex hormone binding globulin. The hormone levels were most strongly associated with the risk of ER–positive/PR–positive breast tumors. In addition, all hormone levels tended to be most strongly associated with in situ disease.

Contact: Amy Smith, Public Affairs, Brigham and Women's Hospital, 617-534-1603, asmith28@partners.org

Korean Study Examines Interaction of Risk Factors for Liver Cancer Mortality

Cigarette smoking, heavy alcohol consumption, and hepatitis B infection are all independent risk factors for death from liver cancer, but they do not interact synergistically, according to a new study.

Liver cancer is one of the most widespread cancers in the world, particularly in Asia and Africa where hepatitis and aflatoxin exposures are common. Risk factors include chronic alcohol consumption, cigarette smoking, dietary aflatoxin exposure, hepatitis B infection, and hepatic cirrhosis, but there has been limited exploration of the combined effects of these exposures.

Sun Ha Jee, Ph.D., M.H.S., of Yonsei University, in Seoul, Korea, and colleagues conducted a prospective cohort study of more than 1.2 million Korean men and women to assess the independent effects and interactions of three risk factors for liver cancer: cigarette smoking, heavy alcohol consumption, and hepatitis B infection. All three risk factors were independently associated with an increased risk of death from liver cancer, but there was no interaction between them.

Contacts: