Other highlights in the February 4 issue of JNCI


Questions Linger About Use of Partial Breast Irradiation

The growing interest in partial-breast irradiation (PBI) and accelerated partial-breast irradiation (APBI) for treatment of early-stage breast cancer make clear the need for ongoing dialogue and well-designed clinical studies of the radiation techniques, concludes a commentary in the February 4 issue of the Journal of the National Cancer Institute.

Breast-conserving therapy has been accepted as an alternative to mastectomy in the management of early-stage breast cancer. Because of the increasing interest in PBI--a technique that directs radiation only at the portion of the breast at high risk for recurrence--and in APBI--which has an accelerated schedule of treatment--the National Cancer Institute hosted a workshop in which issues regarding the equivalency of various radiation therapy approaches and the future needs for research were discussed.

In the commentary, Paul E. Wallner, D.O., and C. Norman Coleman, M.D., of the National Cancer Institute, and colleagues present a summary of the workshop. The authors review the current technology and current science relating to PBI and APBI, and they highlight the need for additional research, training, quality assurance, and procedure standardization.

Preoperative Chemoradiation May Benefit Some Patients with Rectal Cancer

Chemotherapy plus radiation therapy is beneficial for some patients with localized rectal cancer who are carefully selected based on the stage of their disease, according to a new study that uses a statistical model.

Although radical resection and chemoradiation (treatment with both chemotherapy and radiation therapy) after surgery have been the standard therapy for patients with rectal cancer, chemoradiation before surgery is widely used when the extent of the disease is determined through clinical staging. However, there is little information available that directly compares these two approaches.

Jennifer J. Telford, of Brigham and Women's Hospital, and Sapna Syngal, M.D., of Dana-Farber Cancer Institute, and colleagues developed a decision analysis to compare the two strategies, paying particular attention to the effect on 5-year disease-specific survival and life expectancy. Based on their findings, the authors conclude that if efficacy and toxicity after preoperative chemoradiation are equal to or better than that after postoperative chemoradiation in patients with locally advanced rectal cancer, then preoperative staging to select patients appropriate for preoperative chemoradiation is beneficial.

Glycemic Load May Be Associated With Colorectal Cancer

A diet with a high dietary glycemic load may increase the risk of colorectal cancer in women, according to a new study. Glycemic load is a measure of how quickly a food's carbohydrates are turned into sugars by the body (glycemic index) in relation to the amount of carbohydrates per serving of that food. Some examples of foods with a high glycemic load are white breads, white rice, and some pastas.

The growing recognition that colorectal cancer may be promoted by hyperinsulinemia and insulin resistance suggests that a diet inducing high blood glucose levels and an elevated insulin response may contribute to a metabolic environment conducive to tumor growth. Simin Liu, M.D., Sc.D., of Harvard Medical School and Brigham and Women's Hospital, and colleagues looked at information gathered from the Women's Health Study. They looked at the association between dietary glycemic load, overall dietary glycemic index, carbohydrate, fiber, nonfiber carbohydrate, sucrose, and fructose with the subsequent development of colorectal cancer.

Dietary glycemic load was associated with an increased risk of colorectal cancer. Total carbohydrate, nonfiber carbohydrate, and fructose were also associated with increased risk. "A diet with a high glycemic load may increase the risk of colorectal cancer by affecting insulin and insulin-like growth factors or by exacerbating proinflammatory responses, either locally or systemically," the authors write. "Further work is needed to elucidate these mechanisms."

Additional articles appearing in the February 4 JNCI:

  • Characterization of New Antiestrogens: Selective estrogen receptor modulators, such as tamoxifen, are effective against estrogen receptor-positive breast cancer, but their use is limited both by the development of tumor resistance and by their combination of estrogen agonist and antagonist activities. In the February 4 issue of the Journal, Jens Hoffmann, Ph.D., of Schering AG, Berlin, and colleagues report the characterization of two new specific estrogen receptor destabilizers, ZK-703 and ZK-253, both of which can be taken orally, in mouse and rat xenograft breast cancer models. They conclude that these two compounds are potent, long-term inhibitors of growth in both tamoxifen-sensitive and tamoxifen-resistant breast cancer cells.

  • Risk Factors According to Hormone Status:Graham A. Colditz, M.D., Dr.P.H., of Brigham and Women's Hospital and Harvard Medical School conducted a prospective evaluation of breast cancer risk factors according to estrogen receptor (ER) and progesterone receptor (PR) status. They found differences in the incidence of ER-positive and ER-negative breast cancers with age and postmenopausal hormone use, and of PR-positive and PR-negative breast cancers with reproductive history and body mass index after menopause. The authors concluded that incidence rates and risk factors for breast cancer differ according to both ER and PR status; thus, to accurately estimate breast cancer risk, breast cancer cases should be divided according to the ER/PR status of a tumor.

  • Computer-Aided Detection System for Mammography Does Not Change Recall, Breast Cancer Detection Rates:

  • Mobilization of dendtritic cell precursors into the circulation by administration of MIP-1 in mice, Kouji Matsushima, University of Tokyo, et al.

Source: Eurekalert & others

Last reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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