Coffee, tea, caffeine intake, and the risk of cancer in the PLCO cohort.
BACKGROUND
The association between coffee intake, tea intake and cancer has been extensively studied, but associations are not established for many cancers. Previous studies are not consistent on whether caffeine may be the source of possible associations between coffee and cancer risk.


METHODS
In the Prostate, Lung, Colorectal, and Ovarian cancer screening trial, of the 97,334 eligible individuals, 10,399 developed cancer. Cancers included were 145 head and neck, 99 oesophageal, 136 stomach, 1137 lung, 1703 breast, 257 endometrial, 162 ovarian, 3037 prostate, 318 kidney, 398 bladder, 103 gliomas, and 106 thyroid.


RESULTS
Mean coffee intake was higher in lower education groups, among current smokers, among heavier and longer duration smokers, and among heavier alcohol drinkers. Coffee intake was not associated with the risk of all cancers combined (RR=1.00, 95% confidence interval (CI)=0.96-1.05), whereas tea drinking was associated with a decreased risk of cancer overall (RR=0.95, 95% CI=0.94-0.96 for 1+ cups per day vs <1 cup per day). For endometrial cancer, a decreased risk was observed for coffee intake (RR=0.69, 95% CI=0,52-0.91 for ⩾2 cups per day). Caffeine intake was not associated with cancer risk in a dose-response manner.


CONCLUSIONS
We observed a decreased risk of endometrial cancer for coffee intake, and a decreased risk of cancer overall with tea intake.
Division of Public Health, Department of Family and Preventive Medicine, University of Utah School of Medicine, 375 Chipeta Way, Suite A, Salt Lake City, UT 84108, USA.|Huntsman Cancer Institute, University of Utah School of Medicine, 2000 Circle of Hope, Salt Lake City, UT 84108, USA.
Mia
M
Hashibe
Division of Biostatistics, Epidemiology and Public Health, Department of Statistics and Quantitative Methods, University of Milano-Bicocca, Via Bicocca degli Arcimboldi 8, Milan 20126, Italy.
Carlotta
C
Galeone
Department of Internal Medicine and Huntsman Cancer Institute, University of Utah School of Medicine, 2000 Circle of Hope, Salt Lake City, UT 84108, USA.
Saundra S
SS
Buys
Division of Public Health, Department of Family and Preventive Medicine, University of Utah School of Medicine, 375 Chipeta Way, Suite A, Salt Lake City, UT 84108, USA.
Lisa
L
Gren
Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, Room 3-55 1425 Madison Avenue, New York, NY 10029, USA.
Paolo
P
Boffetta
Department of Epidemiology, UCLA Fielding School of Public Health, 71-225 CHS, Box 951772, Los Angeles, CA 90095, USA.
Zuo-Feng
ZF
Zhang
Department of Clinical Sciences and Community Health, University of Milan, Via Vanzetti, 5, Milan 20133, Italy.
Carlo
C
La Vecchia
D000368:Aged; D002110:Caffeine; D003069:Coffee; D015179:Colorectal Neoplasms / Q000453:epidemiology* / Q000209:etiology; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000453:epidemiology* / Q000209:etiology; D008297:Male; D008875:Middle Aged; D010051:Ovarian Neoplasms / Q000453:epidemiology* / Q000209:etiology; D011446:Prospective Studies; D011471:Prostatic Neoplasms / Q000453:epidemiology* / Q000209:etiology; D012307:Risk Factors; D013662:Tea
D003069:Coffee; D013662:Tea; D002110:Caffeine