Coffee is one of the most widely consumed beverage in the world. Many epidemiologic studies have been done to understand the relationship between coffee intake and breast cancer risk and have produced conflicting results (Larsson et al. 2009; Li et al. 2011, 2013; Fagherazzi et al. 2011; Oh et al. 2015). Some studies suggest that there is no association between coffee intake and development of breast cancer (Larsson et al. 2009; Fagherazzi et al. 2011; Li et al. 2013), while some studies suggest that the association is affected by type of hormone receptor status of the breast cancer (Li et al. 2011; Oh et al. 2015). One study showed that there is significant decrease in breast cancer risk with higher coffee intake in estrogen receptor (ER) negative (Li et al. 2011). Another study indicates that coffee intake significantly decreases the risk of overall and estrogen receptor-positive (ER+)/progesterone receptor-negative (PR-) breast cancer (Oh et al. 2015). Thus, if coffee consumption is linked with breast carcinoma, development or treatment is still a matter of research.
