Abstract
BACKGROUND: Epidemiological evidence on the influence of ultra-processed foods (UPFs) on breast cancer prognosis is scarce. No study has examined the UPF-mortality association among Black breast cancer survivors. METHODS: We examined the UPF-mortality relationships among Black women diagnosed with primary breast cancer in New Jersey between 2005 and 2019 (n = 1733), who were participants of the Women's Circle of Health Study and Women's Circle of Health Follow-Up Study. Foods and drinks consumed one year before breast cancer diagnosis were assessed during home interviews by validated food-frequency questionnaires. UPFs were classified according to their degree of processing using the standard NOVA classification system. Death outcomes were ascertained through linkage with New Jersey State Cancer Registry files. Multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for UPF-mortality associations were estimated using Cox and competing risks models, as appropriate. FINDINGS: After a median of 9.3 years of follow-up since diagnosis, 394 total deaths (206 breast cancer-related) were identified. In the multivariable-adjusted model, compared to those in the lowest tertile (median = 2.6 servings/day), women in the highest tertile (median = 8.1 servings/day) of UPF intake had statistically significantly higher breast cancer-specific mortality (HR = 1.40, 95% CI = 1.00-1.96, P(trend) = 0.02) and all-cause mortality (HR = 1.36, 95% CI = 1.06-1.74, P(trend) <0.01). Dose-response analyses revealed a J-shaped association of UPF intake with mortality outcome, with lower risk at under 4 servings/day and higher risk at greater consumption (breast cancer mortality P(for nonlinearity) = 0.01). These associations were attenuated after additional adjustment for total energy intake. INTERPRETATION: This large investigation of UPFs and breast cancer prognosis among Black breast cancer survivors suggests that higher consumption of UPFs, which is associated with greater total energy intake, may adversely influence breast cancer prognosis among Black women, a vulnerable population facing the highest risk of breast cancer mortality in the US. FUNDING: This work was supported by grants from R01CA185623 (Drs. Bandera, Demissie, and Hong), P30CA072720-5929 (Dr. Bandera), R01CA100598 (Dr. Ambrosone), P01CA151135 (Drs Ambrosone, Palmer, and Olshan), R00CA267557 (Dr. Wang) from the National Cancer Institute, and funding from the American Cancer Society RSG-23-1143513-01-CTPS (Dr. Qin) and the Breast Cancer Research Foundation (Dr. Ambrosone). The New Jersey State Cancer Registry, Cancer Epidemiology Services, New Jersey Department of Health, is funded by the Surveillance, Epidemiology and End Results (SEER) Program of the National Cancer Institute under contract 75N91021D00009, the National Program of Cancer Registries (NPCR), Centers for Disease Control and Prevention under grant NU58DP007117 as well as the State of New Jersey and the Rutgers Cancer Institute.