Structural Racism, Lifestyle Behaviors, and Obesity-related Cancers among Black and Hispanic/Latino Adults in the United States: A Narrative Review

One in three adults in the United States has obesity; a chronic disease that is implicated in the etiology of at least 14 cancers. Cancer is the leading cause of death among U.S. Hispanic/Latino adults and the second most common cause of death, after cardiovascular disease, for Black adults. Our country's legacy in overt discrimination (e.g., slavery, segregation) generated inequities across all spheres in which people function as defined by the socioecological model-biological, individual, community, structural-and two of the many areas in which it manifests today are the disproportionate burden of obesity and obesity-related cancers in populations of color. Inequities due to environmental, social, and economic factors may predispose individuals to poor lifestyle behaviors by hindering an individual's opportunity to make healthy lifestyles choices. In this review, we examined the evidence on obesity and the lifestyle guidelines for cancer prevention in relation to cancer risk and outcomes for Black and Hispanic/Latino adults. We also discussed the role of structural and societal inequities on the ability of these two communities to adopt and maintain healthful lifestyle behaviors in accordance with the lifestyle guidelines for cancer prevention and control.

A competing risk analysis of adherence to the American Cancer Society Guidelines on Nutrition and Physical Activity for Cancer Prevention and obesity-related cancer risk in Hispanic/Latino adults in the NIH-AARP Diet and Health Study

Incidence of obesity-related cancers (ORCs) is rising among US Hispanic/Latino adults, which may be partly due to inadequate engagement in healthy lifestyle behaviors. Prior research on cancer prevention guideline adherence and cancer risk has not considered competing events that may lead to misinterpreting the magnitude of risk between guideline adherence and cancer incidence. Among Hispanic/Latino adults (N = 9204) in the NIH-AARP Diet and Health Study, we examined the association between adherence to the 2012 American Cancer Society (ACS) guidelines (high, moderate, low) on nutrition and physical activity for cancer prevention and risk of any first observed ORC using Fine and Gray methods for competing risk analysis. Over a median of 10.5 years of follow-up, there were 619 first ORCs. The cumulative risk of ORC over a 15-year period was not significantly different across ACS guideline adherence categories (high cumulative incidence function [CIF]: 2.2%-5.8%; moderate CIF: 2.2%-6.6%; low CIF: 2.3%-6.7%, PGray's log rank  = .690). In competing risk analysis, high (compared to low) adherence to the ACS guidelines was associated with reduced probability of ORC (subdistribution hazard [SHR]: 0.76, 95% CI: 0.58-0.996, P = .047), with evidence of a linear trend for increasing adherence (Ptrend  = .039). Our findings were consistent with hypothesized inverse associations between ACS guideline adherence and ORC incidence accounting for competing risks. These findings suggest a need for continued public health efforts focused on promoting engagement in healthy lifestyle behaviors to reduce ORC incidence among US Hispanic/Latino adults.

Adherence to the American Cancer Society Guidelines on nutrition and physical activity for cancer prevention and obesity-related cancer risk and mortality in Black and Latina Women's Health Initiative participants

BACKGROUND

Although adherence to the American Cancer Society (ACS) Guidelines on Nutrition and Physical Activity for Cancer Prevention associates with lower risk of obesity-related cancer (ORC) incidence and mortality, evidence in Black and Latina women is limited. This association was examined in Black and Latina participants in the Women's Health Initiative (WHI).

METHODS

Semi-Markov multistate model examined the association between ACS guideline adherence and ORC incidence and mortality in the presence of competing events, combined and separately, for 9301 Black and 4221 Latina postmenopausal women. Additionally, ACS guideline adherence was examined in a subset of less common ORCs and potential effect modification by neighborhood socioeconomic status and smoking.

RESULTS

Over a median of 11.1, 12.5, and 3.7 years of follow-up for incidence, nonconditional mortality, and conditional mortality, respectively, 1191 ORCs (Black/Latina women: 841/269), 1970 all-cause deaths (Black/Latina women: 1576/394), and 341 ORC-related deaths (Black/Latina women: 259/82) were observed. Higher ACS guideline adherence was associated with lower ORC incidence for both Black (cause-specific hazard ratio [CSHR]_highvs.low : 0.72; 95% CI, 0.55-0.94) and Latina (CSHR_highvs.low : 0.58, 95% CI, 0.36-0.93) women; but not conditional all-cause mortality (Black hazard ratio [HR]_highvs.low : 0.86; 95% CI, 0.53-1.39; Latina HR_highvs.low : 0.81; 95% CI, 0.32-2.06). Higher adherence was associated with lower incidence of less common ORC (P_trend  = .025), but conditional mortality events were limited. Adherence and ORC-specific deaths were not associated and there was no evidence of effect modification.

CONCLUSIONS

Adherence to the ACS guidelines was associated with lower risk of ORCs and less common ORCs but was not for conditional ORC-related mortality.

LAY SUMMARY

Evidence on the association between the American Cancer Society Guidelines on Nutrition and Physical Activity for Cancer Prevention and cancer remains scarce for women of color. Adherence to the guidelines and risk of developing one of 13 obesity-related cancers among Black and Latina women in the Women's Health Initiative was examined. Women who followed the lifestyle guidelines had 28% to 42% lower risk of obesity-related cancer. These findings support public health interventions to reduce growing racial/ethnic disparities in obesity-related cancers.