Dietary Anthocyanins: Impact on Colorectal Cancer and Mechanisms of Action

Colorectal cancer is the third most common malignancy in males and the second most common in females, with significant variations in the worldwide distribution, and remains among four leading causes of cancer deaths overall, shows global cancer statistics. The highest incident rates are found in economically developed countries, whereas the lowest rates are noted in Africa and South-Central (Jemal et al., 2011). However, striking increase in colorectal cancer incident trends is observed in areas historically at low risk, such as Spain and some Eastern European (the Czech Republic and Slovakia) and Eastern Asian countries (Japan). On the other hand, generally high incident rates over the past several decades are going down in the Unites States (Center et al., 2009). These recent “perturbations” in colorectal cancer trends probably result from a combination of risk factors, including obesity, sedentary lifestyle, increased prevalence of smoking, excessive alcohol consumption and “westernization” in dietary habits a diet rich in red and processed meat and low intake of fruits and vegetables (Center et al., 2009; Chao et al., 2005; Jemal et al., 2011). Decreasing incident and mortality rates are mainly associated with colorectal cancer screening and improved treatment. Prognosis of these patients depends on the stage of the cancer at diagnosis. As the AJCC (American Joint Committee on Cancer) stage increases from stage I to stage IV, the 5-year overall survival rates decrease dramatically, reaching 90% if the disease is detected early when still localized, though just 39% of colorectal cancers are found at this stage. Almost 25% of patients have a metastatic disease at diagnosis, with a 5-year survival of less than 10% (Goldberg et al., 2007). The primary treatment for colorectal cancer is surgical resection. More than two-thirds of patients undergo radical surgery, but 30-50% of patients who present with stage II or III tumors ultimately experience disease recurrence and distant metastases (Rodriguez-Moranta et al., 2006). Although a broader base of treatment options for metastatic colorectal cancer (mCRC) has evolved in recent years, 50 70% of mCRC