Alterations in a tumor suppressor gene called p53 are more prevalent in breast cancer of African-American women than white women

Alterations in a tumor suppressor gene called p53 are more prevalent in breast cancer of African-American women than white women, according to a new study.

This study, published August 9, 2004 in the online edition of CANCER, a peer-reviewed journal of the American Cancer Society, “represents the first reported series of increased prevalence of p53 alterations in African-American breast cancer patients,” according to an accompanying editorial. Free abstracts of the study and editorial are available on CANCER Online.

Ethnic differences in the incidence and mortality rates of breast cancer are noted in the United States and worldwide. In the U.S., the most apparent differences are seen between African-American and white women. African-American women have lower incidence rates of the disease, but have higher mortality rates. Moreover, African-American women present at a younger age and with more aggressive disease.

Explanations for these racial/ethnic differences have included socioeconomic factors, nutrition, medical comorbidities, and healthcare behavior. However, analyses demonstrate that higher mortality risk remains independent of these factors. Recent studies also show that tumors in African Americans have significant different molecular characteristics on histopathology, such as lacking estrogen receptors.

Beth A. Jones, Ph.D., M.P.H. from Yale University School of Medicine and her colleagues studied the breast tumors of 145 African-American and 177 white women to further characterize the pattern of alterations of genes known to relate to tumor development and be associated with worse prognosis.

The authors found that African-American women were four times more likely than white women to show significant alterations in a tumor suppressor gene, p53. However, the prevalence of alterations in other cancer-related genes, HER-2/neu, and the previously unstudied, c-met, did not differ significantly across racial groups. Overall, the burden of poor prognostic factors was found to be greater among African-American women.

In an accompanying editorial, Lisa A. Newman, M.D., of the University of Michigan says the study is the first population-based study to demonstrate “a significant ethnic/race difference in p53 expression.” Taken in the context of breast cancer, this study’s novel use of molecular biology has opened “the door to improved understanding of ethnicity-related variation in breast cancer risk and outcome,” writes Dr. Newman.

Article: “African-American/White Differences in Breast Carcinoma: p53 Alterations and Other Tumor Characteristics,” Beth A. Jones, Stanislav V. Kasl, Christine L. Howe, Mary Lachman, Robert Dubrow, Mary McCrea Curnen, Hosanna Soler-Vila, Alicia Beeghly, Fenghai Duan, Patricia Owens, CANCER; Published Online: August 9, 2004 (DOI: 10.1002/cncr.20500); Print Issue Date: September 15, 2004.

Editorial: “Breast Carcinoma in African-American and White Women: Application of Molecular Biology to Understand Outcome Disparities,” Lisa A. Newman, CANCER; Published Online: August 9, 2004 (DOI: 10.1002/cncr.20501); Print Issue Date: September 15, 2004.

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