Background & aims: Few studies have examined the association between coffee intake and survival after diagnosis of colorectal cancer (CRC). We performed a prospective study to investigate the association between coffee intake after a diagnosis of CRC and mortality.
Methods: We collected data from the Nurses' Health Study (1984-2012) and Health Professionals Follow-up Study (1986-2012), following 1599 patients diagnosed with stage 1, 2, or 3 CRC. CRC was reported on questionnaires and ascertained by review of medical records and pathology reports; intake of food and beverages was determined from responses to semi-quantitative food frequency questionnaires. Participants were asked how often during the previous year that they consumed coffee, with 1 cup as the standard portion size. The first questionnaire response collected at least 6 months but not more than 4 years after diagnosis was used for assessment of post-diagnostic intake (median time from diagnosis to the dietary assessment, 2.2 years). The last semi-quantitative food frequency questionnaire prior to diagnosis was used to assess pre-diagnostic dietary intake.
Results: During a median of 7.8 years of follow-up, we documented 803 deaths, of which 188 were because of CRC. In the multivariable adjusted models, compared with nondrinkers, patients who consumed at least 4 cups of coffee per day had a 52% lower risk of CRC-specific death (hazard ratio [HR] 0.48; 95% CI, 0.28-0.83; P for trend=.003) and 30% reduced risk of all-cause death (HR, 0.70; 95% CI, 0.54-0.91; P for trend <.001). High intake of caffeinated and decaffeinated coffee (2 or more cups/day) was associated with lower risk of CRC-specific mortality and all-cause mortality. When coffee intake before vs after CRC diagnosis were examined, compared with patients consistently consuming low amounts (less than 2 cups/day), those who maintained a high intake (2 or more cups/day) had a significantly lower risk of CRC-specific death (multivariable HR, 0.63; 95% CI, 0.44-0.89) and death from any cause (multivariable HR, 0.71; 95% CI, 0.60-0.85).
Conclusions: In an analysis data from the Nurses' Health Study and Health Professionals Follow-up Study, we associated intake of caffeinated and decaffeinated coffee after diagnosis of CRC with lower risk of CRC-specific death and overall death. Studies are needed to determine the mechanisms by which coffee might reduce CRC progression.
Keywords: Colon Cancer; Diet; Post-diagnostic Coffee Intake; Rectal Cancer.
Copyright © 2018 AGA Institute. Published by Elsevier Inc. All rights reserved.