Daily Coffee Tied to Lower Risk for Prostate Cancer Recurring
http://www.medscape.com/viewarticle/810258
Prediagnostic Consumption
Nick Mulcahy
Aug 30, 2013
Drinking 4 or more cups of coffee a day is associated with a lower risk for prostate cancer recurrence and progression, according to a prospective study published online August 2 in Cancer Causes and Control.
The study authors found that men who drank that much coffee daily had a 59% reduced risk for prostate cancer recurrence and/or progression, compared with those who drank 1 or fewer cups per week (P for trend = .01).
The coffee consumption was measured before a prostate cancer diagnosis, not afterward, note the authors, led by Milan Geybels, a PhD candidate in the Department of Epidemiology of Maastricht University in the Netherlands. He worked on the research while studying at the Fred Hutchinson Cancer Research Center in Seattle, where one of his coauthors, Janet Stanford, PhD, is codirector of the program in prostate cancer research.
For more than 5 years, the authors prospectively followed a population-based cohort of 630 prostate cancer patients from King County, Washington. During that period, they assessed adverse prostate cancer outcomes.
They found no association between coffee drinking and reduced mortality from prostate cancer. However, the study was not powered to assess that relation because there were only 38 disease-related deaths.
The study was designed to determine whether the bioactive compounds in coffee and tea have an impact on the course of prostate cancer.
There are “several potentially chemopreventive compounds in coffee” the authors note, including cafestol, kahweol, chlorogenic acid, and caffeic acid. However, definitive research is lacking and none of these compounds can be credited with a sure effect, they say.
Total caffeine intake has been associated with a reduced risk for several cancer types, including basal cell carcinoma, glioma, and ovarian cancer, the authors point out.
All participants completed a validated food frequency questionnaire to determine their prediagnosis diet and beverage consumption.
There were many more coffee than tea drinkers in the cohort. About 61% of the men consumed at least 1 cup of coffee per day, whereas only 14% of the men consumed 1 or more cups of tea per day.
The team found that that tea consumption is unrelated to prostate cancer recurrence/progression.
Consistent With Another Observational Study
The evaluation of the men for disease progression was rigorous and unprecedented in this type of study, according to the authors.
“We used detailed information on follow-up prostate-specific antigen levels, use of secondary treatment for prostate cancer, and data from scans and biopsies to assess occurrence of metastases and cause-specific mortality during follow-up. Using these detailed data, we could determine whether a patient had evidence of prostate cancer recurrence or progression,” Geybels said in a press statement.
The findings are “consistent” with the results from another prospective cohort study, say the authors.
In that Health Professionals Follow-up Study cohort, researchers “observed a strong inverse association between coffee consumption and risk of lethal prostate cancer” (J Natl Cancer Inst. 2011;103:876-884). Men who drank 6 or more cups per day had a modestly decreased risk (18%) of developing prostate cancer, compared with men who drank no coffee. However, this association was much stronger for lethal prostate cancer. Men who drank 6 or more cups per day had a 60% decreased risk for metastatic/lethal prostate cancer, compared with men who drank no coffee.
Geybels and colleagues believe that money needs to be spent to further investigate whether coffee can help men diagnosed with prostate cancer. Large prospective studies are “urgently needed,” they say. However, at this point, clinicians should not recommend coffee or specific coffee components for the secondary prevention of prostate cancer, they emphasize.
Coffee Is Not Good for All Men
Coffee drinking can be problematic for some men, the authors note in a press statement.
“Although coffee is a commonly consumed beverage, we have to point out that increasing one’s coffee intake may be harmful for some men. For instance, men with hypertension may be vulnerable to the adverse effects of caffeine in coffee. Or, specific components in coffee may raise serum cholesterol levels, posing a possible threat to coronary health. Patients who have questions or concerns about their coffee intake should discuss them with their general practitioner,” Geybels said.
The authors point out that they do not know whether the men consumed caffeinated or decaffeinated coffee. They also had no data on how the coffee was prepared (espresso, boiled, filtered), or whether the bioactive chemicals in coffee differ according to the method of preparation.
The National Cancer Institute, the Fred Hutchinson Cancer Research Center, the Prostate Cancer Foundation, and the Dutch Cancer Society funded the research. The authors have disclosed no relevant financial relationships.
Cancer Causes Control. Published online August 2, 2013.
http://link.springer.com/article/10.1007%2Fs10552-013-0270-5