For patients with stage III colon cancer, drinking four or more cups of coffee per day may reduce risk of recurrence by 42% and death by 34%.
Charles S. Fuchs, MD
Charles S. Fuchs, MD
Does drinking a lot of coffee reduce colon cancer recurrence risk? Possibly, according to a study published online in the Journal of Clinical Oncology which found that for patients with stage III colon cancer, drinking four or more cups of coffee per day may reduce risk of recurrence by 42% and death by 34%.
The results are based on data from 953 patients with stage III colon cancer who during, and 6 months following, adjuvant chemotherapy prospectively reported their intake of caffeinated coffee, decaffeinated coffee, and nonherbal tea, as well as 128 other items. Patients who consumed four cups or more of total coffee per day experienced an adjusted hazard ratio for colon cancer recurrence or mortality of 0.58 (95% CI, 0.34-0.99), compared with those who did not drink coffee (P = .002) and increasing caffeine intake also resulted in significant reduction in cancer recurrence or mortality (HR = 0.66; 95% CI, 0.47-0.93; P = .006).
Nonherbal tea and decaffeinated coffee were not associated with patient outcomes.
Study author Charles S. Fuchs, MD, director of the Gastrointestinal Cancer Center at the Dana-Farber Cancer Institute, expanded on the results in a recent interview.
What prompted this study?
The bigger question is, “Why study diet and lifestyle as it pertains to survival for patients diagnosed with colorectal cancer?” Over years of study, we have identified that diet and lifestyle are clear risk factors for colorectal cancer. Individuals who exercise regularly, maintain a healthy weight, and eat properly have a reduced risk of developing colorectal cancer. I would suggest that colon cancer is the best understood cancer for dietary and lifestyle risk factors.
However, the people who are the most interested in this study are not healthy individuals, but people who were recently diagnosed. Approximately 70% of newly diagnosed patients believe there is a diet, lifestyle, or supplement that will improve their cure rate. The issue is, there have never really been adequate studies looking at the impact of diet and lifestyle changes on that population.
Why was coffee investigated specifically as a potential lifestyle factor that could impact survival?
We were determined to conduct a large, prospective study where we measured diet and lifestyle among people who were being treated for colon cancer close to the time of diagnosis. We then followed them to see what aspects of their diet and lifestyle might improve their cure rate. All of the people we studied were treated as part of clinical trials, as well as had surgery and appropriate adjuvant therapy. We collected data on their diet and lifestyle choices before their cancer recurred. It was collected before the patient knew the ultimate outcome.
We examined a number of factors that reduced risk, and they all seemed to be associated with a reduced risk of getting diabetes. We believe that the factors that put you at higher risk for diabetes may also influence the biology of the body and result in a higher risk of recurrence of colon cancer following treatment.
One factor of interest is coffee. A number of studies show that patients who consume regular coffee drinks have a lower risk of developing diabetes. Because of the relationship between coffee and diabetes, and the relationship between diabetes risk and colon cancer, we wanted to investigate if coffee also reduced the risk of colon cancer recurrence.
What were the results of your investigation?
In a questionnaire that we administered to 1000 patients, we measured their coffee consumption, including caffeinated and decaffeinated, as well as other caffeinated beverages, such as tea. We found that regular coffee drinkers experienced a significant reduction in risk of having their cancer recur or dying of cancer. Our study specifically looked at patients with stage III colon cancer or lymph node-positive colon cancer. There was about a 42% improvement in disease-free survival for people who consumed four or more cups of coffee per day following their treatment of colon cancer.
We did look at caffeinated versus decaffeinated coffee, and it seems that only caffeinated coffee has a benefit. When we looked at caffeine intake from any source—chocolate or other beverages—we did see that increasing caffeine intake is associated with a superior outcome. Therefore, it appears that caffeine may be the key to the survival benefit, but it requires confirmation.
Is there any understanding of why coffee may reduce recurrence?
We believe that the relationship between coffee and the recurrence of colon cancer is reflective of coffee’s effect on energy pathways. Extensive literature shows that coffee reduces the risk of type 2 diabetes, and we think that coffee—or some component of coffee—affects energy balance and insulin pathways that impact diabetes. We think these same pathways are key in the survival of colon cancer cells. We know that insulin pathways are growth promoting for colon cancer cells. If coffee has a negative effect on those pathways, thereby reducing the incidence of diabetes, perhaps whatever is in the coffee is also negatively affecting the colon cancer cells.
Should there be clinical recommendations for colon cancer based on these results?
Based on this study, I would not necessarily recommend anything at this point. The study was really interesting, and we believe it was well conducted; however, it needs to be confirmed. Patients really need to discuss these things with their own oncologist before making any lifestyle changes.
There are no downsides to coffee that I am aware of. People wonder if caffeine is bad for you; however, numerous studies show that people who consume regular coffee drinks have a somewhat longer lifespan, have a lower risk of heart disease, and a lower risk of type 2 diabetes. Therefore, I do not know of any risk associated with regularly drinking coffee.
More studies of this could lead to dietary recommendations and allow us to understand the biology of colon cancer better. If coffee works, we need to understand how it works and what biological process is happening as a result.
What next steps should be taken in this research?
An independent prospective study of patients with colon cancer needs to be done. We are also doing other independent cohorts, so we will look again and see if we can validate this or reproduce it in other patient populations. Other groups are trying to create similar studies, as well. I think there will be an opportunity, now that the data is in the public domain, for others to confirm it.
Is there any possible association between coffee and risk of developing colon cancer?
No one has adequately looked at coffee and risk of developing colon cancer. However, many of the same lifestyle factors that are linked to cancer recurrence do tend to be linked to cancer prevention.
Guercio B, Sato K, Niedzwiecki D, et al. Coffee intake, recurrence, and mortality in stage III colon cancer: results from CALGB 89803 (Alliance) [published online August 17, 2015]. J Clin Oncol. doi: 10.1200/JCO.2015.61.5062.