Association of tumor differentiation with caffeine and coffee intake in women with breast cancer.

Caffeine, which has been linked to benign breast disease, has an antineoplastic effect in experimental animals, whereas in tissue cultures it inhibits mitoses and induces cell differentiation. We examined caffeine and coffee intake in 101 women with breast cancer to determine whether either or both influence cell differentiation in tumors as well. Nutrient analysis was performed by the Nutrition Coding Center of the University of Minnesota with the Nutrition Data system from the National Heart, Lung, and Blood Institute. Stepwise logistic regression, with tumor differentiation (well and moderate versus poor) as the dependent variable, was used. The analysis indicates that caffeine and/or coffee intake has a significant association with tumor differentiation as women with moderately to well-differentiated tumors had higher caffeine and coffee intake. This raises the question whether caffeine or coffee consumption may help induce cell differentiation and slow tumor growth.