Other highlights in the March 16 JNCI

03/10/05

Distribution of Risk Factors Largely Explains Ethnic Differences in Breast Cancer Rates

Differences in breast cancer rates between racial and ethnic garoups can be largely explained by the distribution of risk factors except in African American women, according to a new study.

Women in ethnic and racial minority groups have lower breast cancer incidence than white women. However, among women with breast cancer, African American women are diagnosed at a more advanced stage, have larger tumors, and are more likely to have estrogen receptor-negative disease than white women. Breast cancer mortality is also higher among African American women than in white women. However, all these differences have remained largely unexplained.

Rowan T. Chlebowski, M.D., Ph.D., of the Los Angeles Biomedical Research Institute in Torrance, Calif., and colleagues examined racial and ethnic differences in breast cancer incidence and outcome in more than 150,000 women participating in the Women's Health Initiative. They found that the lower incidence of breast cancer in Hispanic, Asian/Pacific Islander, and American Indian/Native American women was mostly explained by differences in the distribution of breast cancer risk factors, such as age, family history, reproductive history, education level, and alcohol consumption.

Differences in the distribution of breast cancer risk factors also explained some, but not all, of the difference in breast cancer incidence between African American and white women. Despite the lower incidence of breast cancer in African American women, among those who developed breast cancer, mortality was higher in African American women than in white women. Breast cancers in the African American women were more likely to have the characteristics of poor prognosis tumors than those in other racial and ethnic groups. The authors suggest that the higher rates of obesity and high-grade cancer in African American women could explain some of the mortality difference.

Contact: David Feuerherd, LA BioMed, 310-222-2820, df@issuesmanagement.com

Variant Polymorphism May Affect Aspirin Chemoprevention of Colorectal Cancer

A new study has found that, among women with a common variant polymorphism that affects an enzyme that metabolizes aspirin, regular aspirin use is associated with a decreased risk of colorectal adenoma. But regular aspirin use is not associated with the same reduction in risk of colorectal adenoma among women who have a normal form of the enzyme.

Regular aspirin use has been associated with an overall reduced risk of colorectal adenoma. More rapid aspirin metabolism may decrease the therapeutic effect of aspirin. Consequently, polymorphisms in the enzyme UGT1A6, which metabolizes aspirin, may modulate the protective benefit of aspirin.

To determine whether polymorphisms in UGT1A6 are associated with colorectal adenoma risk, Andrew T. Chan, M.D., M.P.H., of Massachusetts General Hospital in Boston, and colleagues conducted a nested case–control study of 1,062 women participating in the Nurses' Health Study. They found that among the women with variant polymorphisms, regular aspirin use was associated with a decreased risk of adenoma, and the risk decreased further with higher doses of aspirin. However, among the women the normal form of the enzyme, regular aspirin use was not associated with a reduced risk, and these women did not benefit from higher aspirin doses.

Contact:

  • through March 11: Susan McGreevey, 617-724-2764, smcgreevey@partners.org
  • after March 11: Donita Boddie, 617-724-5627, dboddie@partners.org

    New Tool Can Assess Side Effects of Treatment and Prevention of Breast Cancer

    A new tool may be able to help clinicians and researchers monitor and assess the side effects of the treatment and prevention of breast cancer. The tool may also be able to help women who are looking for information on what to expect from breast cancer treatment or chemoprevention, according to a new study.

    Annette L. Stanton, Ph.D., of the Jonsson Comprehensive Cancer Center at the University of California, Los Angeles, and colleagues used the Breast Cancer Prevention Trial (BCPT) Symptom Checklist to develop the BCPT Symptom Scales to assess side effects among four groups of women participating in different breast cancer studies. They identified eight factors corresponding to the physical symptoms associated with cancer treatment, chemoprevention, menopause, and normal aging: hot flashes, nausea, bladder control, vaginal problems, musculoskeletal pain, cognitive problems, weight problems, and arm problems. The authors conclude that the BCPT Symptom Scales is a valuable tool to assess side effects associated with treatment and prevention of breast cancer.

    Contact: Kim Irwin, Media Relations, UCLA Jonsson Cancer Center, 310-206-2805, kirwin@mednet.ucla.edu

    PLCO Trial Reports Baseline Data for Prostate Cancer Screening

    The prostate component of the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Trial is designed to determine the impact of annual screening with prostate-specific antigen (PSA) testing and digital rectal exam on mortality from prostate cancer by comparing one group of men who receive screening with a control group of men undergoing routine medical care. In a new study, Gerald L. Andriole, M.D., of the Washington University School of Medicine in St. Louis, and colleagues report findings from the initial round of screening. The final results of the trial are still several years away.

    Of the more than 38,000 men in the screening group, 7.5% had a positive digital rectal exam (suspicious for cancer), and 7.9% had a PSA level higher than 4 ng/mL. Of the men who had positive screening tests, 74.2% underwent additional diagnostic testing, and 31.5% had a prostatic biopsy within a year. Overall, 1.4% of the men in the screening group were diagnosed with prostate cancer, most of which was clinically localized cancer.

    Contact: Gwen Ericson, Washington University, 314-286-0141, ericsong@wustl.edu

    Also in the March 16 JNCI:

  • Risk of Cardiac Death After Radiotherapy for Breast Cancer Has Declined, Study Finds: http://www.eurekalert.org/emb_releases/2005-03/jotn-roc031005.php
  • Antiretroviral Therapy May Prevent Excess Risk of Some Cancers in People With HIV: http://www.eurekalert.org/emb_releases/2005-03/jotn-atm031005.php

    Source: Eurekalert & others

    Last reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
        Published on PsychCentral.com. All rights reserved.

     

     

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