Importance: Several compounds found in coffee possess antioxidant, anti-inflammatory, and insulin-sensitizing effects, which may contribute to anticancer activity. Epidemiological studies have identified associations between increased coffee consumption and decreased recurrence and mortality of colorectal cancer. The association between coffee consumption and survival in patients with advanced or metastatic colorectal cancer is unknown.
Objective: To evaluate the association of coffee consumption with disease progression and death in patients with advanced or metastatic colorectal cancer.
Design, setting, and participants: This prospective observational cohort study included 1171 patients with previously untreated locally advanced or metastatic colorectal cancer who were enrolled in Cancer and Leukemia Group B (Alliance)/SWOG 80405, a completed phase 3 clinical trial comparing the addition of cetuximab and/or bevacizumab to standard chemotherapy. Patients reported dietary intake using a semiquantitative food frequency questionnaire at the time of enrollment. Data were collected from October 27, 2005, to January 18, 2018, and analyzed from May 1 to August 31, 2018.
Exposures: Consumption of total, decaffeinated, and caffeinated coffee measured in cups per day.
Main outcomes and measures: Overall survival (OS) and progression-free survival (PFS).
Results: Among the 1171 patients included in the analysis (694 men [59%]; median age, 59 [interquartile range, 51-67] years). The median follow-up time among living patients was 5.4 years (10th percentile, 1.3 years; IQR, 3.2-6.3 years). A total of 1092 patients (93%) had died or had disease progression. Increased consumption of coffee was associated with decreased risk of cancer progression (hazard ratio [HR] for 1-cup/d increment, 0.95; 95% CI, 0.91-1.00; P = .04 for trend) and death (HR for 1-cup/d increment, 0.93; 95% CI, 0.89-0.98; P = .004 for trend). Participants who consumed 2 to 3 cups of coffee per day had a multivariable HR for OS of 0.82 (95% CI, 0.67-1.00) and for PFS of 0.82 (95% CI, 0.68-0.99), compared with those who did not drink coffee. Participants who consumed at least 4 cups of coffee per day had a multivariable HR for OS of 0.64 (95% CI, 0.46-0.87) and for PFS of 0.78 (95% CI, 0.59-1.05). Significant associations were noted for both caffeinated and decaffeinated coffee.
Conclusions and relevance: Coffee consumption may be associated with reduced risk of disease progression and death in patients with advanced or metastatic colorectal cancer. Further research is warranted to elucidate underlying biological mechanisms.