By: Leah Lawrence
Increasing trial diversity and tailoring interventions for underrepresented groups may facilitate health equity in breast cancer prevention and control, according to experts.
A recent review cites studies suggesting that obesity, unhealthy diets, and physical inactivity may increase the risk of developing breast cancer and dying from it, but lifestyle interventions may lower those risks.1
The results of these studies may not be generalizable, however, as many were conducted predominantly in non-Hispanic White patients, according to review author Elisa V. Bandera, MD, PhD, of Rutgers Cancer Institute of New Jersey in New Brunswick, and colleagues.
“There is a critical need to include racially/ethnically diverse populations in cancer prevention and control research or to specifically target minority populations in which disparities are known to exist to achieve much needed health equity,” the authors wrote.
Data suggest that Hispanic women have a lower incidence of breast cancer than non-Hispanic White women.2 However, breast cancer incidence is on the rise in Hispanic women, and breast cancer is the leading cause of cancer death in this group.
Although breast cancer incidence rates are similar for non-Hispanic White women and Black women, death rates are higher for Black women.1 Asian/Pacific Islander women have the lowest incidence and death rates of all racial/ethnic groups.
These differences could be explained, in part, by “differences in health behaviors, such as physical activity or differences in overweight or obesity, which we know is associated with decreased survival and breast cancer survival specifically,” said Scherezade K. Mama, DrPH, an assistant professor in the Department of Health Disparities Research at the University of Texas MD Anderson Cancer Center in Houston.
One large meta-analysis showed that physical activity reduced breast cancer risk in both pre- and postmenopausal women.3 Both adult weight gain and greater body adiposity were associated with an increased risk of breast cancer in postmenopausal women, but the evidence was less consistent in premenopausal women.
Although the meta-analysis included more than 100 studies, the authors still concluded that more studies are needed of different racial and ethnic groups that may have different risk patterns.
In their review, Dr Bandera and colleagues noted that studies among Black women have found “mostly null associations between adult BMI and premenopausal breast cancer risk.”1 The authors also noted that “few studies have evaluated the impact of obesity on breast cancer risk among Hispanic women.”
Data do suggest the prevalence of obesity varies by racial or ethnic group, with non-Hispanic Black women having higher rates (56.9%) than Hispanic (43.7%), non-Hispanic White (39.8%), and Asian (17.2%) women.1
Barriers to Trial Diversity
Like studies assessing breast cancer risk factors, trials of lifestyle interventions are often lacking in diversity, according to Dr Bandera and colleagues.
One barrier to trial diversity is that many cancer trials are conducted at academic medical centers or large universities with cancer centers that serve mostly non-Hispanic White patient populations, said Rachel J. Meadows, PhD, MPH, assistant member of the faculty at the Center for Epidemiology & Healthcare Delivery Research at JPS Health Network in Fort Worth, Texas.
“If that is where the trial is and where it is recruiting, then often you are not even reaching racial/ethnic minority populations who are often more likely to go to federally qualified health centers or county safety-net health systems,” Dr Meadows said.
Another barrier is that even when members of underserved communities are invited to participate, participation might not be feasible.
“Individuals with low income, which unfortunately tend to be racial/ethnic minorities, are less likely to have paid time off or days off during the week to go participate in a research trial,” Dr Meadows said. “For trials looking at diet or exercise, they might not have access to a gym membership, exercise equipment, places to buy healthy foods, or the extra money required to participate.”
However, research has shown that participation and retention in trials targeting underserved participants can be high, which counters the notion that underserved populations are unwilling to participate in trials.4
“Researchers and funders of trials need to work on minimizing barriers to participation, especially for racial/ethnic minorities, those with low income, and beyond,” Dr Meadows said.
There are a number of ways to adapt or tailor lifestyle interventions or programs for underserved minorities in general and for women specifically, Dr Mama said. For example, she and her colleagues previously published a study of faith-based mind-body interventions in Black adults.5
“We tailored lifestyle interventions by incorporating scripture into the intervention to better appeal to and engage African-American adult churchgoers,” Dr Mama said.
Participants were randomly assigned to a movement-based mind-body intervention or control. The intervention was developed in partnership with a pastor and senior member of the church. Trends showed greater improvements in physical activity and psychosocial well-being among participants in the mind-body intervention group.
“Importantly though, at the end, 100% of the intervention participants said they would recommend it to a friend or family,” Dr Mama said.
Researchers at MD Anderson also developed the “Tu Salud ¡Sí Cuenta! Your Health Matters!” campaign, which was intended to improve eating behaviors and anthropometric outcomes in Hispanic communities.
The campaign included TV and radio segments as well as newsletters and discussions with community health workers that disseminated culturally and language-appropriate messages about physical activity and eating behaviors.
A study of the campaign’s efficacy showed that any exposure to a campaign component was associated with a lower rate of unhealthy food consumption.6
Dr Meadows emphasized that when designing studies, it is important for researchers to remember that different people have different preferences when it comes to diet and exercise.
“There can be healthy diets that reflect different cultural groups and include food that is similar to what they are already used to eating,” she said. “For example, not everyone is going to adopt a Mediterranean diet because it includes foods they have never eaten before or are not used to.”
The same is true for physical activity interventions, Dr Mama said.
She and her colleagues studied the use of culturally adapted and standard home-based exercise interventions in a group of Hispanic breast cancer survivors in Project VIVA!7 The researchers used culturally tailored phone calls and newsletters to support home-based exercise and observed good rates of participation and adherence.
Another study of Black breast cancer survivors tested a community-based walking intervention and showed significant increases in steps per day and attitudes toward exercise as well as decreases in BMI, body weight, percentage of body fat, and other measures, including blood pressure.8
Despite these positive results, “there is a lot of work left to do to achieve better health equity in cancer prevention and control,” Dr Mama said.
“We have to do a better job generally of assessing social determinants of health that contribute to cancer disparities,” she noted. “Additionally, we need to do more to include community members and stakeholders in these efforts.”
- Bandera EV, Alfano CM, Qin B, et al. Harnessing nutrition and physical activity for breast cancer prevention and control to reduce racial/ethnic cancer health disparities. Am Soc Clin Oncol Educ Book. 2021;41:1-17. doi:10.1200/EDBK_321315
- American Cancer Society. Cancer Facts & Figures for Hispanics/Latinos 2018-2020. Accessed July 13, 2021. https://www.cancer.org/content/dam/cancer-org/research/cancer-facts-and-statistics/cancer-facts-and-figures-for-hispanics-and-latinos/cancer-facts-and-figures-for-hispanics-and-latinos-2018-2020.pdf
- Chan DSM, Abar L, Cariolou M, et al. World Cancer Research Fund International: Continuous Update Project—systematic literature review and meta-analysis of observational cohort studies on physical activity, sedentary behavior, adiposity, and weight change and breast cancer risk. Cancer Causes Control. 2019;30:1183-1200. doi:10.1007/s10552-019-01223-w
- Ojha RP, Jackson BE, Lu Y, et al. Participation and retention can be high in randomized controlled trials targeting underserved populations: a systematic review and meta-analysis. J Clin Epidemiol. 2018;98:154-157. doi:10.1016/j.jclinepi.2017.11.014
- Mama SK, Bhuiyan N, Chaoul A, et al. Feasibility and acceptability of a faith-based mind-body intervention among African American adults. Transl Behav Med. 2020;10(4):928-937. doi:10.1093/tbm/iby114
- Heredia NI, Lee MJ, Mitchell-Bennett L, Reininger BM. Tu Salud ¡Sí Cuenta! Your Health Matters!: a quasi-experimental design to assess the contribution of a community-wide campaign to eating behaviors and anthropometric outcomes in a Hispanic border community in Texas. J Nutr Educ Behav. 2017;49(10):801-809.e1. doi:10.1016/j.jneb.2017.06.008
- Mama SK, Song J, Ortiz A, et al. Longitudinal social cognitive influences on physical activity and sedentary time in Hispanic breast cancer survivors. Psychooncology. 2017;26(2):214-221. doi:10.1002/pon.4026
- Wilson DB, Porter JS, Parker G, Kilpatrick J, et al. Anthropometric changes using a walking intervention in African American breast cancer survivors: A pilot study. Prev Chronic Dis. 2005;2(2):A16.
Barbara Jacoby is an award winning blogger that has contributed her writings to multiple online publications that have touched readers worldwide.