Having highly dense breasts may be associated with an increased risk of a second breast cancer among women who have had a ductal carcinoma in situ (DCIS), according to a new study.
Women with DCIS--a noninvasive condition in which abnormal malignant-appearing cells are found in the lining of a breast duct--have a substantially increased risk of a second breast cancer, but few predictors of this risk have been identified. Having extensive areas of breast tissue that appear dense on mammograms has been associated with a four to six times greater risk of primary breast cancer compared with women who have small or no areas of dense breast tissue.
To see if breast density was related to the risk of getting a second breast cancer after DCIS, Laurel A. Habel, Ph.D., of Kaiser Permanente Medical Care Program in Oakland, Calif., and colleagues studied 504 women from the National Surgical Adjuvant Breast and Bowel Project (NSABP) B-17 trial who had DCIS. They examined the mammograms taken when the women were diagnosed with DCIS and then calculated the risk of subsequent breast cancer events.
While only about 7% of the women had highly dense breasts--75% or more of their breasts were composed of dense tissue--they had 2.8 times the risk of subsequent breast cancer (DCIS or invasive) compared with women who had the least dense breasts--less than 25% of their breasts were composed of dense tissue. In addition, women with dense breasts also had 3.2 times the risk of invasive breast cancer and 3.0 times the risk of any ipsilateral breast cancer (cancer in the same breast as the DCIS).
The authors suggest that breast density may reflect the activity of hormones and other growth factors. In addition, breast density may affect the accuracy of disease surveillance through mammography and clinical breast examination after treatment for DCIS.
Contact: Alexandra Matisoff-Li, National Media Relations, Kaiser Permanente, 510-271-5624, Alexandra.matisoff-li@kp.org
New Colon Cancer Staging System Affects Survival Predictions
A new system for classifying colon cancer by stage may provide better overall estimates of survival by providing more substages than the old system, according to a new study. Such a system may help to provide more appropriate care to colon cancer patients.
The American Joint Committee on Cancer (AJCC) formulates classification systems for specific cancers, including colon cancer. These systems are designed to stratify patients in terms of predicted survival, to help select the most effective treatment, to determine prognosis, and to evaluate methods of cancer control. In 2002, AJCC released their sixth edition, which increased the number of stages for colon cancer from four to seven by further stratifying two criteria, tumor depth of penetration and number of positive lymph nodes.
To see how survival outcomes by stage changed with the new staging system, Jessica B. O'Connell, M.D., of the David Geffen School of Medicine at University of California, Los Angeles, and colleagues used data from the Surveillance, Epidemiology, and End Results Program (SEER) to compare survival rates associated with colon cancer stages defined according to both the new (sixth edition) and the old (fifth edition) systems.
They found that the new AJCC system stratifies survival more distinctly than the old AJCC system by providing more substages. However, under the new system, stage IIIa colon cancer is associated with better survival than stage IIb. In current clinical practice, stage III patients receive chemotherapy but stage II patients generally do not. This practice, they conclude, may be the reason for the differences in survival.
In an editorial, Harry B. Burke, M.D, Ph.D., of George Washington University School of Medicine in Washington, writes that new therapies are not included in the TNM staging system, which limits its clinical utility. He calls for a paradigm shift in outcome prediction to new, computer-based systems that provide personalized medicine.
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Researchers Describe Method for Characterizing Dual-Site Tumors
Cancer patients can often have tumors at two different sites. Whether these tumors arise independently or one is the result of metastasis from the other can affect a patient's prognosis, treatment options, and response to therapy. In a new study, Ian J. Jacobs, M.D., of University College London, and colleagues describe a novel method that uses a genetic and statistical algorithm to establish the origin of synchronous endometrial and ovarian, bilateral ovarian, or endometrial and bilateral ovarian tumors using genetic data gathered from the tumors.
When the researchers compared their results to previous diagnoses based on histologic type and grade of the tumors, most of the diagnoses were in agreement, however, there were important discrepancies in about a quarter of cases. The authors suggest that this new method has promise as a rapid diagnostic test for the clinical management of patients with dual-site tumors.
Contact: Jenny Gimpel, Communication Office, University College London, 44-207-679-9739, j.gimpel@ucl.ac.uk
Noninvasive Technique May Predict Neuroblastoma Response to Chemotherapy
Neuroblastoma in children can be difficult to cure, despite aggressive treatment. The ability to assess a tumor's response to chemotherapy could help to optimize treatments for these patients. In a new study, Magnus Lindskog, of Astrid Lindgren Children's Hospital, Karolinska Hospital, in Stockholm, Sweden, and colleagues demonstrate the ability of a technique called proton magnetic resonance spectroscopy to predict response and resistance to chemotherapy in experimental rat neuroblastoma models. The technique provides detailed biochemical information about a tumor and can be performed at the same time as diagnostic magnetic resonance imaging (MRI).
Contact: Magnus Lindskog, Karolinska Hospital, magnus.lindskog@kbh.ki.se
Also in the October 6 JNCI:
- Selective Efficacy of Depsipeptide in a Xenograft Model of Epstein-Barr Virus–Positive Lymphoproliferative Disorder, Roychowdhury et al., Ohio State University
- Effects of Angiogenesis Inhibitors on Vascular Network Formation by Human Endothelial and Melanoma Cells, van der Schaft et al., Northwestern University Feinberg School of Medicine
- Breast Density, Rapid Tumor Growth Contribute to Mammogram Failure in Women in Their Forties: http://www.eurekalert.org/emb_releases/2004-10/jotn-bdr093004.php
- Arylamine Exposure Related to Bladder Cancer Risk: http://www.eurekalert.org/emb_releases/2004-10/jotn-aer093004.php
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. Visit the Journal online at http://jncicancerspectrum.oupjournals.org/.
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JNCI Journal of the National Cancer Institute