Other highlights in the August 6 issue of JNCI

Some phytoestrogens--estrogens found in plant foods--consumed at the levels in the typical American-style diet are associated with a reduced risk of endometrial cancer, a new study has found.

The development of endometrial cancer is related to prolonged exposure to estrogens without cyclic exposure to progesterone. Phytoestrogens may have antiestrogenic effects. Phytoestrogens are found in soy-based foods, and many foods contain added soy (such as white bread) or have low to moderate amounts of phytoestrogens (such as coffee and orange juice). Pamela L. Horn-Ross, Ph.D., of the Northern California Cancer Center, Union City, Calif., and colleagues evaluated the associations between dietary intake of seven specific compounds representing three classes of phytoestrogens (isoflavones, coumestans, and lignans) and the risk of endometrial cancer in a case-control study of women ages 35 to 79 in the San Francisco area.

Consumption of isoflavones and lignans, but not coumestans, was associated with a reduced risk of endometrial cancer, particularly among postmenopausal women. Obese postmenopausal women consuming relatively low amounts of phytoestrogens had the highest risk of endometrial cancer; however, the interaction between obesity and phytoestrogen intake was not statistically significant.

Study Examines Origins of Fatigue in Breast Cancer Survivors

Persistent fatigue in breast cancer survivors might be associated with a chronic inflammatory process involving T cells, a new study suggests.

About 30% of women successfully treated for breast cancer suffer persistent fatigue of unknown origin. Earlier studies have found elevated levels of several inflammatory markers in circulating blood among breast cancer survivors experiencing fatigue. To identify the immunologic basis for these elevations, Julienne E. Bower, Ph.D., of the Cousins Center for Psychoneuroimmunology at the UCLA Neuropsychiatric Institute in Los Angeles, and colleagues examined cellular immune system status in 20 fatigued breast cancer survivors and 19 matched non-fatigued breast cancer survivors.

Fatigued survivors, compared with non-fatigued survivors, had statistically significantly increased numbers of circulating T lymphocytes, with pronounced elevation in the numbers of CD4+ T lymphocytes and CD56+ effector T lymphocytes. These changes were independent of patient demographic and treatment characteristics. The increased numbers of circulating T cells correlated with elevations in the level of serum interleukin 1 receptor antagonist (a marker of inflammation). The authors note that these results require confirmation in a larger study.

Contact: Kim Irwin, UCLA, 310-206-2805, kirwin@mednet.ucla.edu

Also in the August 6 JNCI:

• Topical Drug Imiquimod Shown to Induce Apoptosis: Imiquimod is a topical drug that has shown effectiveness in the treatment of basal cell carcinoma, actinic keratoses, and cutaneous metastases of malignant melanoma. To study the mechanism by which imiquimod induces apoptosis, or cell death, in cancer cells, Michael P. Schön, M.D., and Margarete Schön, Ph.D., of the Rudolf-Virchow-Center for Biomedical Research at Julius-Maximilians-University, Würzburg, Germany, and colleagues looked at various types of cells treated with imiquimod, its analog resiquimod, or neither. They found that imiquimod, but not resiquimod, induced apoptosis in keratinocyte-derived tumor cells and that this activity was independent of membrane-bound death receptors. The authors conclude that imiquimod is a compound with the potential to induce apoptosis in skin cancer cells, possibly by circumventing mechanisms developed by the tumor to resist apoptotic signals.
  
• Integrin Polymorphism Associated With Increased Cancer Risk: Increased tumor cell expression of integrins containing the beta-3 subunit is associated with increased progression to invasive tumors, whereas inhibition of beta-3 integrin expression and/or function may reduce tumor growth and metastasis. Stig E. Bojesen, of the Herlev University Hospital, Denmark, and colleagues examined whether a specific polymorphism of the beta-3 integrin, Leu33Pro, which modulates the function of the integrin, influences cancer risk among the general population in Denmark. Although only 2.7% of the population was homozygous for the polymorphism, the authors found that the cumulative cancer incidence and the age-adjusted relative risk of all cancers, and specifically ovarian cancer, breast cancer, and melanoma, were higher in homozygotes than in non-carriers. The authors found that individuals who were heterozygous for the polymorphism were not at an increased risk of cancer. They conclude that individuals who are homozygous for the Leu33Pro polymorphism may be at increased risk for some cancers.
  
• State-of-the-Science Statement on Cancer Symptom Management Published: Despite advances in early detection and effective treatment, cancer remains one of the most feared diseases. The most common side effects of cancer and its treatments are pain, depression, and fatigue. In July 2002, the National Institutes of Health convened a State-of-the-Science Conference on Symptom Management in Cancer: Pain, Depression, and Fatigue to examine the current state of knowledge regarding the management of pain, depression, and fatigue in individuals with cancer and to identify directions for future research. The conclusions of the 14-member panel are published in this issue of the Journal of the National Cancer Institute.

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.