Introduction to the Special Section on Cancer Disparities

Despite improved methods for detecting and treating many forms of cancer, ethnic and racial minority groups continue to experience higher rates of cancer-related morbidity and mortality compared with Whites (1). Consequently, reducing and ultimately eliminating cancer disparities is now a national priority (2). Considerable efforts are being made to identify factors that contribute to disparities in cancer incidence and outcomes, and to translate this information into effective interventions for ameliorating disparities among racial/ethnic groups. For example, the Centers for Population Health and Health Disparities were established by the NIH to conduct transdisciplinary research to identify factors that contribute to disparities in cancer and other diseases, and to translate this knowledge toward the elimination of these disparities (3, 4). Additionally, the Patient Navigator Research Program was created by the National Cancer Institute to develop and evaluate interventions that are designed to reduce the amount of time between cancer diagnosis and treatment (5). A key goal of the navigator program is to determine if patient navigation is an effective strategy for reducing disparities in cancer outcomes.

This special Focus section was assembled to highlight the importance of cancer disparities and to identify areas where continued efforts are needed. This collection of reports underscores several important issues. First, the study by DeLancey and colleagues (6) shows that it is imperative to continue to monitor temporal trends in racial differences in cancer mortality. Using data from the Surveillance Epidemiology and End Results, the investigators found that African American–White differences in cancer mortality increased during the 1990s through 2004 for breast, prostate, and colon cancer, although mortality declined within each race during that time. This finding is significant because breast, prostate, and colon cancer mortality can be reduced through effective screening and treatment. Thus, these findings illustrate the continued need for coordinated efforts to ensure access to and use of screening and effective treatment modalities among minorities.

The report by Gerend and Pai (7) identifies some of the factors that may be barriers to accessing and using breast cancer screening among African American women. Using the Social Determinants of Health Disparities conceptual framework (8), Gerend and Pai identify economic, psychological, cultural, and geographic factors that have been shown to contribute to racial disparities in breast cancer mortality. Importantly, this report underscores the importance of evaluating the contribution of social factors to racial differences in breast cancer mortality and offers several suggestions for future research and interventions that may be effective in reducing the effect of social determinants on cancer care services.

In contrast to the substantial amount of research that has been conducted over the past 25 years to understand factors that contribute to African American–White differences in cancer outcomes (7), the reports by Taylor and colleagues (9) and Reyes-Ortiz and colleagues (10) draw attention to the paucity of research on cancer outcomes among other racial/ethnic groups in the United States, many of whom represent large immigrant populations. Because of the higher rates of cervical cancer mortality observed among Vietnamese women, Taylor and colleagues examined rates and predictors of Pap testing in this population. Consistent with a recent report indicating that community-based strategies are among the most effective in terms of addressing racial disparities in health outcomes (11), the report by Taylor and colleagues emphasizes the importance of community-based strategies to improve use of cancer screening in immigrant populations, but also identifies methodologic challenges to community-based research in this population and other groups that have recently immigrated to the United States. Reyes-Ortiz and colleagues (10) illustrate how disparities may exist in specific aspects of the cancer screening and care continuum, even when a particular racial/ethnic group (e.g., Hispanics) fares well on overall cancer incidence and mortality. Given that the bulk of cancer disparities research over the last several decades has focused on African Americans, the reports from Taylor and colleagues and Reyes-Ortiz and colleagues remind us that it is important to monitor and address disparities in cancer outcomes in all racial/ethnic groups where disparities exist.

The research conducted by Kendzor and colleagues (12) highlights the clustering of cancer risk factors within individuals and the potential role for cancer prevention and control strategies with respect to reducing disparities. This study found that close to 90% of smokers enrolled in a smoking cessation program reported at least one risk factor (e.g., obesity, sedentary behavior, and at-risk alcohol use) in addition to smoking. Moreover, Hispanics and African Americans were significantly more likely than Whites to be affected by multiple cancer risk factors. The results of this study suggest that attention to multiple risk factors during smoking cessation treatment may have promise with respect to addressing disparities in cancer and other diseases that disproportionately affect African Americans and Hispanics.

Finally, the study by Nicholson and colleagues (13) shows that the way in which racial disparities are framed in the media is likely to have significant implications for screening behavior among African Americans. Using an experimental design with a community-based sample of African-Americans, the investigators found that participants who were exposed to messages framed to emphasize progress with respect to racial differences in colon cancer (e.g., African Americans are improving) reported more positive emotional reactions and more desire to be screened than those participants exposed to messages that emphasized disparities. The results of this study show the importance of determining how to more precisely communicate cancer-related messages in a way that enhances use of cancer care services.

In summary, the reports included in this Focus section clearly show the complexities inherent in addressing racial/ethnic disparities in cancer and highlight the necessity of continued efforts focused on eliminating disparities. As we move forward with the next generation of research in this area, the general failure to reduce disparities in cancer incidence and mortality over the last several decades illustrates the necessity of incorporating transdisciplinary perspectives on the determinants of disparities and the development of innovative intervention approaches that go beyond the status quo.