Pre- and post-diagnostic meat intake in relation to risk of recurrence and mortality among individuals with stage I–III colorectal cancer

Processed meat and unprocessed red meat intakes are associated with increased colorectal cancer (CRC) risk, but evidence on associations with mortality after a CRC diagnosis is inconsistent. To date, no studies examined associations between unprocessed poultry intake and mortality, or assessed cancer recurrence risk as a separate outcome measure. We included data from 2484 individuals, who were newly diagnosed with stage I–III CRC, participating in 2 prospective cohort studies. Dietary intake was assessed at diagnosis and 6 months after diagnosis. Multivariable Cox proportional hazards regression models and restricted cubic splines were used to examine associations between pre- and post-diagnostic meat intake and risk of recurrence and all-cause mortality. We performed subgroup analyses by sex, disease stage and primary tumour location. During a median follow-up time of 5.0 years for recurrence analyses and 6.4 years for mortality analyses, 336 recurrences and 409 deaths occurred. Pre- and post-diagnostic processed meat and unprocessed red meat intakes were not associated with risk of recurrence nor all-cause mortality. At both timepoints, a higher unprocessed poultry intake was non-linearly associated with a decreased mortality risk, with the lowest risk observed at 20 g/day (hazard ratio: 0.63, 95% confidence interval: 0.47–0.85), compared to 0 g/day. Results were not substantially different by sex, disease stage and primary tumour location. To conclude, a higher pre- and post-diagnostic intake of unprocessed poultry, but not processed meat and unprocessed red meat, was associated with a decreased all-cause mortality risk in individuals with stage I–III CRC. Future studies in independent study populations should confirm these findings.