Racial differences in dietary changes and quality of life after a colorectal cancer diagnosis: a follow-up of the Study of Outcomes in Colorectal Cancer Survivors cohort

Abstract

Background: Substantial racial disparities exist in colorectal cancer (CRC) survival.

Objective: This was an exploratory study to assess the racial differences in dietary changes in relation to quality of life (QoL), recurrence, and survival after a CRC diagnosis.

Design: Four hundred fifty-three stage II CRC patients were enrolled in the cohort study through the North Carolina Central Cancer Registry. Self-reported diet, physical activity, treatment, comorbidities, demographic characteristics, and QoL were collected at diagnosis and 12 and 24 mo after diagnosis. QoL was assessed with the Functional Assessment of Cancer Therapy-Colorectal (FACT-C) and the Medical Outcomes 12-Item Short Form Health Survey (SF-12) inventories. An overall dietary index score was calculated. Generalized estimating equations and logistic regression models were used to explore potential associations. Statistical power for this study was ∼50%.

Results: African Americans (n = 81) were more likely to increase intakes of reduced-fat milk, vegetables, and fruit and decrease intakes of regular cheese, red meat, fried food, fast food, and fat (P < 0.05) than were Caucasians (n = 184) 24 mo after diagnosis. The least-squares means ± SEs for changes in dietary index were 6.05 ± 0.40 and 4.07 ± 0.27 for African Americans and Caucasians, respectively (P < 0.001). African Americans exhibited higher scores on portions of the FACT-C (colorectal cancer subscale: β = 1.04; 95% CI: 0.26, 1.82) and the SF-12 (Physical Component Summary: β = 2.49; 95% CI: 0.51, 4.48). Those who improved their dietary quality over 24 mo had lower risk of recurrence and mortality combined (OR: 0.42; 95% CI: 0.25, 0.72).

Conclusions: African Americans made more healthful changes in diet and had a higher QoL than did Caucasians in this underpowered study that used self-reported dietary data. No racial differences in recurrence or survival were evident, although improvements in dietary quality did reveal survival benefits overall. More prospective research on racial disparities in health behavior changes after diagnosis is desperately needed.

Keywords: colorectal cancer; diet; quality of life; race; survivors.

FIGURE 1

Study of Outcomes in Colorectal Cancer Survivors enrollment flow diagram.