Abstract 3732: Inflammatory breast cancer rates among different ethnic and racial groups in the United States

Inflammatory breast cancer (IBC) is considered to be the most aggressive form of breast cancer. In the US, the proportion of incidences of IBC cases ranges from 2% to 5%. Understanding the determinants of IBC rates among different populations may help to design prevention strategies. Internationally, IBC rates have been linked to socioeconomic status (SES). In the US, the analysis of the National Cancer Institute Surveillance Epidemiology and End Results (SEER) data for the period of 1988-2000, and data for 1994-1998 from the North American Association of Central Cancer Registries demonstrated greater IBC rates among Blacks compared to Whites and similar rates among Whites and Hispanics. However, the Hispanic population in the US has grown significantly in the last decade and its SES status is generally lower compared to non-Hispanic Whites. Therefore, we hypothesized that IBC rates in Hispanics have increased since the reported rates from 1994-1998 and are higher than among Whites.We used the SEER database to estimate age-adjusted and age-specific rates of IBC among ages 20-84 in three racial/ethnic groups: Whites, Blacks, and Hispanics (including both Whites and Blacks). IBC cases were categorized using Common Stage Extension Codes 71-73. Age-specific IBC rates were estimated for three age-groups: 20-45 (pre-menopausal), 45-60 (peri-menopausal), and 60-84 (post-menopausal).During 2004-2007, a total of 3107 IBC cases were diagnosed among the 20-84 year old population covered by the SEER registries. Among them, 2436 cases were diagnosed in Whites, 470 in Blacks, and 403 in Hispanics. Age-adjusted rates among Blacks were ∼ 1.4-fold greater than in Whites, whereas rates among Hispanics were ∼1.4-fold lower than Whites and ∼2-fold lower than Blacks. Age-specific rates among Blacks were greater than among Whites at all ages. Age-specific rates among Hispanics in pre- and peri-menopausal groups were similar to Whites, but became lower after menopause, which could account for overall lower age-adjusted rates among Hispanics.In summary, our analysis indicates different IBC rates in Whites, Blacks, and Hispanics. New information about lower IBC rates among Hispanics poses a question of what accounts for these differences. Further investigations of the ethnic/racial rates disparities may elucidate the underlying risk factors for IBC.Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3732. doi:10.1158/1538-7445.AM2011-3732

Duke Scholars

Author Shara Reihani