Patients with bladder cancer who had been exposed to high levels of arsenic have tumors with greater chromosomal instability, and these tumors tend to be more aggressive than tumors from unexposed patients, according to a study in the November 20 issue of the Journal of the National Cancer Institute. Lee E. Moore, Ph.D., of the National Cancer Institute, and colleagues examined chromosomal alterations in bladder tumor DNA in 123 patients who had been exposed to arsenic in their drinking water. The authors found that the total number of chromosomal changes was higher in patients exposed to higher arsenic levels. They also found that the average number of chromosomal changes was increased with tumor stage and grade, raising the possibility that bladder tumors from arsenic-exposed individuals may behave more aggressively than tumors from unexposed patients and may result in increased deaths.
Contact: NCI Office of Communications, 301-496-6641, ncipressofficers@mail.nih.gov.
Study Identifies Risk Factors for Classical Kaposi's Sarcoma
Smoking is associated with a decreased risk of classical Kaposi's sarcoma--a cancer of the lymphatic endothelial skin cells--but a number of other factors are associated with an increased risk of this disease, according to a study in the November 20 issue of the Journal of the National Cancer Institute. James J. Goedert, M.D., of the National Cancer Institute, and his colleagues found that, among men, KS risk decreased approximately 20% for each 10 pack-years reportedly smoked, and it was decreased sevenfold with more than 40 pack-years smoked. An increased KS risk was associated with topical corticosteroid use, infrequent bathing, and a history of asthma. The authors caution that their findings "should in no way be interpreted as an endorsement of smoking, because the many serious complications of smoking far outweigh its effect on classical KS." However, they say that understanding how smoking affects KS risk may lead to a better understanding of the disease and to interventions for its prevention.
Contact: NCI Office of Communications, 301-496-6641, ncipressofficers@mail.nih.gov.
Leptin May Control Proliferation of Breast Cancer Cells
Leptin, the growth factor associated with weight gain, appears to control the proliferation of breast cancer cells, according to a study in the November 20 issue of the Journal of the National Cancer Institute. Increased levels of leptin has been tied to obesity, which is a known risk factor for breast cancer. Xin Hu, Ph.D., Margot P. Cleary, Ph.D., of the University of Minnesota's Hormel Institute in Austin, Minn., and their colleagues found that leptin enhanced the proliferation of both normal and cancerous breast cells. In further studies, the researchers found that genetically obese mice had less normal cellular maturation in their mammary glands than lean mice. "These results suggest a novel association of diet-induced obesity, mammary gland development, and the risk for breast cancer," the authors conclude.
Contact: Brenda Hudson, University of Minnesota Academic Health Center, 612-624-5680, bhudson@umn.edu.
Detecting DNA Allelic Imbalance in Blood May Increase Specificity for Ovarian Cancer Detection
Current screening tools for ovarian cancer lack sensitivity and specificity. One potential approach to screening for the disease may be to detect allelic imbalance, the loss or gain of chromosomal regions, in tumor DNA released into the blood after tumor cells die. In the November 20 issue of the Journal of the National Cancer Institute, Hsueh-Wei Chang, Ph.D., Ie-Ming Shih, M.D., Ph.D., and their colleagues at the Johns Hopkins University School of Medicine compared allelic imbalance with several other ovarian cancer screening tests, including measuring tumor DNA concentration in the blood, and found that allelic imbalance could be detected with high specificity in tumor DNA in the blood of patients with ovarian cancer. The authors conclude that allelic imbalance should be studied further as a screening tool.
Contact: Vanessa Wasta, Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, 410-955-1287, wastava@jhmi.edu.
Note: The Journal of the National Cancer Institute is published by Oxford University Press and is not affiliated with the National Cancer Institute. Attribution to the Journal of the National Cancer Institute is requested in all news coverage.
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