Journal of Cancer Education

, Volume 28, Issue 2, pp 314–318

Debunking ‘Race’ and Asserting Social Determinants as Primary Causes of Cancer Health Disparities: Outcomes of a Science Education Activity for Teens


    • Department of Biology, Health Equity InstituteSan Francisco State University
  • Cathy Samayoa
    • Department of Biology, Health Equity InstituteSan Francisco State University
  • Carol Umanzor
    • Department of Biology, Health Equity InstituteSan Francisco State University

DOI: 10.1007/s13187-013-0474-0

Cite this article as:
Márquez-Magaña, L., Samayoa, C. & Umanzor, C. J Canc Educ (2013) 28: 314. doi:10.1007/s13187-013-0474-0


Cancer health disparities are often described as the unequal burden of cancer deaths in one racial/ethnic group compared to another. For example, national cancer statistics in the USA shows that Blacks die the most for 9 of the top 10 cancers in men and women. When asked about the underlying causes for this disparity, teen participants speculated that it is primarily due to genetics or biology. This speculation appears to be based on a false concept of ‘race.’ A science activity was created to counter the false concept that genetics/biology underlie the categorization of humans into different ‘races.’ This activity provided teen participants with first-hand evidence of how they are all related at one genetic locus, and how they are more genetically related across racial/ethnic groups than within them. Results of surveys given before and after the activity show that they change their perceptions of ‘race.’ Before the activity, they view themselves as most related at the genetic level to 1–2 well-known individuals (i.e., celebrities) who they perceive as members of their own ‘race’ mainly because of similar appearance. After the activity, they view themselves as related to more/all the celebrities or they state that they do not know to whom they are most related. This increased awareness of the uncertainty between the apparent ‘race’ of an individual and their genetics drives teens to dismiss genetics or biology as the primary cause of racial/ethnic disparities in cancer outcomes. Instead, they consider the unequal distribution of the social determinants of health as the primary cause of cancer disparities.


Race and cancerScience education activityCancer health disparities

‘Race’ and Cancer

Minority populations suffer disproportionate burdens of cancer in the USA [1]. These populations belong to many ethnic groups and are commonly (and incorrectly) thought to be of different ‘races.’ Therefore the term ‘race’ is placed in single quotes to underscore that what constitutes race and racial groups are constructed categories of social status that have changed throughout American history [25], and not a biologically meaningful term. In fact, when the results of the Human Genome Project were unveiled in 2000, leaders of the research teams involved in this monumental effort concurred that ‘race’ is not a valid scientific category [6]. Nonetheless, the use of ‘race’ as a biologically legitimate concept persists in both the popular press and scientific literature [7].

While data to support the sociopolitical construct of ‘race’ as a social determinant of health that explains cancer health disparities are strong [8], most geneticists and biologists concur that race is not a valid scientific category. Instead, the theory of human evolution argues that we are one human race with a common African ancestor [9]. Consequently, from a genetic point of view, modern humans are all members of the same ‘race,’ and harbor a mixture of genes inherited from their common African and more recent ancestors [10]. It is this admixture that can be used to sort individuals into groups for population-based studies of how genes or biology may play a role in health disparities [11, 12]. However, in the popular press and in much of the scientific literature, Americans are sorted into different racial/ethnic groups that roughly correspond to the sociopolitical categories used by the developers of the US Census.

Over time, developers of the US Census have changed the categories used for ‘race’ and ethnicity, as well as the nature of the population groups included in each. For example, the Caucasian category that included individuals of European, Indian, and Pakistani descent no longer exists; instead these groups are now divided into the White, Asian Indian, and other Asian categories. Furthermore, Spaniards are now categorized as Hispanics, whereas in the 2000 census, they were considered White in keeping with their European ancestry. In fact, the US Census Bureau state that the race item generally reflects a social definition of ‘race’ and does not attempt to define it at the biological or genetic level [13]. Instead the categories used to collect racial data are developed in accordance with guidelines developed by the US Office of Management and Budget [14].

Despite the fact that the categories on the US Census have changed over time, they are used to standardize collection of cancer statistics that include biological measures. While this may be appropriate for monitoring progress (or lack thereof) in equalizing the burden of cancer in ethnic minority populations, they may be inappropriate for studying biological/genetic factors that contribute to cancer incidence and mortality [15]. Nonetheless, national cancer statistics and the results of biomedical research are typically reported using categories based on the ‘race’ categories on the US Census.

The most recent 2010 census had fifteen ‘race’ categories and asked if individuals were of Hispanic origin. To report national cancer statistics for racial/ethnic groups, these ‘race’ categories are aggregated into five racial and two ethnic categories in the Surveillance, Epidemiology, and End Result (SEER) database in accordance with the 1997 guidelines from the US Office of Management and Budget [14]. In this database, the five racial categories consist of American Indian or Alaska native, Asian, Black or African American, Native Hawaiian or Other Pacific Islander, and White. The two ethnic categories are Hispanic/Latino, or non-Hispanic/non-Latino [16].

Taken together, the fact that ‘race’ is not a biologically meaningful term and that the racial ethnic categories used on the census and SEER database are dynamic and subject to sociopolitical pressures suggest that this self assignment cannot be used to understand cancer disparities at the biological/genetic level. Instead, self-reported ‘race’ can only drive understanding of how this social determinant of health plays a role in the unequal burden of cancer for minority populations. Yet, when presented with racial ethnic data generated from national cancer statistics (SEER database), a common speculation is that differences in cancer outcome between groups are primarily due to biological or genetic differences.

As an initial step towards addressing this confusion in the general US population, a science education activity for teens was developed, implemented, and assessed. The activity was designed to allow teens to obtain first-hand evidence of how they are all related at one genetic locus, and how variations in that locus are shared across ‘races.’ Teens were chosen as participants for this activity because the National Science Education Standards dictate that students in this age range be introduced and receive continuing instruction on genes, heredity, and biological evolution [17]. Moreover, this group may be more open minded to the information presented given the reluctance of much of the general public to accept that ‘race’ is not a scientifically valid category [7].

Hands-on Science Education Activity

Before the hands-on activity, teen participants were shown graphs documenting deaths caused by all cancers in the USA for several racial/ethnic groups during the period from 1975 to 2002. These graphs were generated from the SEER database [16] and documented deaths due to cancer for the following racial/ethnic groups: White, Black, Asian/Pacific Islander, American Indian/Alaska native, and Hispanic/Latino. From these data, teens were asked to speculate as to the cause of the greater number of deaths amongst Blacks than all other groups. For the five separate activities assessed in this report, the reasons postulated for the disparities included genetics/biology, culturally specific behaviors, access to health care, poverty, environmental injustice, lack of cultural sensitivity, racism, and discrimination. In fact, genetics/biology was advanced as a primary cause of the cancer health disparities documented by the graphs.

To explore the postulate that genetics/biology is a primary cause of cancer health disparities, the teen participants engaged in a hands-on activity to obtain first-hand knowledge of how they are related at the genetic level. The group reasoned that if genetics/biology are responsible for the disparities shown by the SEER graphs, then African Americans (e.g., Blacks) in the group would be more genetically similar to one another than to members of other ‘races’ found in the group (e.g., American Indians, Asians, Latinos, and Whites). This idea was tested by the teens in a lab-based activity using techniques common to the disciplines of human molecular evolution, medical genetics, and forensics to analyze their own DNA. They collected their own cheek cells, isolated DNA from them, amplified a segment of the isolated DNA (a region of mitochondrial DNA), and analyzed the amplified DNA product.

The first part of the lab-based activity was devoted to showing the teens how they are all related at one genetic locus using the polymerase chain reaction (PCR) and agarose gel electrophoresis. Under particular conditions, PCR allows for amplification of segments of DNA only if they contain identical sequences at each end. The teens used this reaction to amplify a region of their mitochondrial DNA that was isolated from their own cheek cells. They then visualized the products of their PCR by agarose gel electrophoresis finding that all their reactions yielded products 673 base pairs (bp) in length (Fig. 1, top panel). This finding demonstrates that they all maintain identical DNA sequences in their mitochondrial DNA. More importantly, it provided first-hand evidence to the teens that they are all related at the genetic level consistent with the modern theory of human evolution that all humans belong to a single race [9, 10].
Fig. 1

Visualization of amplified and treated DNA by agarose gel electrophoresis. Top panel: Amplified mitochondrial DNA from Asian, Black, White, and Latino individuals showing a common product size of 673 base pairs (bp). Bottom panel: DNA fragments following treatment of amplified DNA shown in top panel. Two patterns are generated by the treatment revealing a single difference in the DNA sequence. The same pattern is found for DNA isolated from Asian, White, Latino, and Black individuals (lanes 2, 3, 5, and 6, respectively) showing they have the same sequence. A different pattern is found for the DNA from Latino and Black individuals (lanes 4 and 7) showing they share the single difference in the DNA sequence

The second part of the hands-on activity was devoted to showing teens how the DNA product can be further analyzed to reveal a single difference in the DNA sequence that uncovers subpopulations in the group. In one case, this difference protects the DNA from cutting at one site upon treatment with a particular enzyme. In the other case, the DNA is amenable to cutting at all sites. Thus, the teens treated their DNA products with the cutting enzyme and visualized the pattern of fragments that were obtained by agarose gel electrophoresis. If the product is protected from cutting at one site, a fragment of 541 bp is obtained, whereas two fragments of 288 and 253 bp are obtained if it is amenable to cutting. Additional smaller fragments are also obtained because of other cutting sites that are found in both subpopulations. While the smaller fragments are found in both subpopulations, the presence of either the 541-bp fragment or the two 288- and 253-bp fragments sorts the teens into subpopulations that have a single difference in the DNA that is investigated.

Upon inspection of the pattern of fragments obtained following treatment, the teens were often surprised by the results obtained, and were forced to reconsider their hypothesis that genetics/biology plays a major role in cancer health disparities. To the surprise of many teens, they found that their pattern was more similar to individuals of a different ‘race’ than to individuals of their same ‘race.’ For example, in Fig. 1 (lower panel), teens who self-identify as Asian, Black, White, and Latino displayed the same pattern, and this pattern differed from other teens who self-identify as Latino and Black. These results allow the teen participants to reach the conclusion that differences in their mitochondrial DNA sequences are not uniquely linked to a particular racial/ethnic group. They find that these differences are shared, and do not sort by racial/ethnic groups.

After reaching conclusions about the results obtained the teen are told that this is not only the case for mitochondrial DNA sequences, but for all DNA sequences in the human genome. As humans, we share 90 % of our genetic variation, and the variation capable of causing a particular disease (like cancer) is shared more amongst individuals afflicted with that disease who are of different ‘races’ than amongst healthy members of the same ‘race’ [19]. Thus, the teen’s postulate that cancer health disparities are primarily driven by genetic/biological factors is not supported by the first-hand data they obtain. Instead, the teens conclude that social determinants of health (e.g., poverty, environmental injustice, racism, and discrimination) that are associated more with particular racial/ethnic groups are the primary cause of cancer disparities.


Our assessment was aimed at evaluating attainment of the following learning objectives for the teen participants: (1) increased understanding of the modern theory of human evolution that explains how we are all members of one human race; and (2) greater awareness of the scientific fact that we are more genetically related across self-identified ‘races’ than within them. Taken together, attainment of these learning objectives was expected to enable teens to debunk ‘race’ and assert social determinants of health as primary causes of cancer disparities.

To monitor changes in perception of ‘race’ as a result of participation in this science education activity, pre- and post-surveys were administered to 46 teen participants engaged in five offerings of the activity. The surveys consisted of the following prompt, “I think that at the genetic level I am most related to the following person? You may check more than one.” Following the prompt, the names and pictures and names of contemporary celebrities were provided with a box next to them for the teens to check. The names and pictures of eight celebrities were provided that included female and male representatives of the following racial/ethnic groups: African American, Asian American, Latino, and White. A box for an “I do not know” response was also provided. Additionally, the teens were asked to provide a two- to three-sentence response to “Why?” they made a particular selection(s).

We predicted that before the laboratory activity, teens would select one to two celebrities that they considered female and/or male members of their self-identified race. In fact, this was generally found to be the case (Fig. 2). We further speculated that after the lab-based activity, teens would select more celebrities (and perhaps all of them), and/or the “I do not know” box. While the number of “I do not know” responses remained about the same, the number of teens who selected all the celebrities increased dramatically (Fig. 2). More importantly, the qualitative responses of the teens to “Why?” they made particular selections before and after the educational activity support the conclusion that we attained our learning objectives.
Fig. 2

Results of pre and post surveys, n = 48. Teen participants were asked to select individuals they felt they were most related to at the genetic level. They chose from eight contemporary celebrities who were named and pictured, and who represented African American, Asian American, Latino, and White groups

The participant responses to the question “Why?” suggest that they based their selections upon different criteria before and after the educational activity. These changes are consistent with attainment of the learning objectives for the activity. Before the activity, 86 % of the teen participants made their selections based upon the apparent ‘race’ of the celebrity (e.g., appearance) stating that they were of the same ‘race.’ After the activity, 76 % of the teens did not use racial/ethnic appearance as a criterion for selection. Instead 41 % described similar DNA sequences as a basis for their selection (Fig. 3).
Fig. 3

Results of qualitative answers to “Why?” obtained before and after the lab-based activity. Categories for the most frequent responses and the percent of respondents giving these responses are provided


The science education activity described in this article was designed as a first step to increase understanding of the primary causes of cancer health disparities that exist among racial/ethnic groups in the US. While genetics and biology are viewed by some as a primary cause of these disparities, this view is not supported by modern scientific concepts of race. However, it is clear that sociopolitical assignments of ‘race’ and the concomitant power and privilege (or lack thereof) that come with the assignment play a pivotal role in health and health outcomes [18]. Thus, this activity aimed to debunk the misconception of different genetic/biological ‘races,’ and to assert differences in the social determinants of health that arise due to racial inequality as the primary causes of cancer disparities found for racial/ethnic groups in the US. The following written comments from teen participants suggest this objective was achieved, “I am dumbfounded to see how ridiculous our society is. We differentiate each other into certain categories when we are all just one human race.” And yet because these categories exist, “I learned about the inequality that exists in the medical field.”


We thank Drs. Laura Mamo and Sonja Mackenzie for their critical comments and helpful suggestions. The outreach activities were supported by NIH/NCI grant U56CA096217 to reduce cancer disparities.

Copyright information

© Springer Science+Business Media New York 2013