Preclinical and Clinical Studies on the Efficacy of Phytochemicals in Cancer Treatment

Cancer, a persistent challenge to global health, is one of the prominent contributors of morbidity and mortality, regardless of the degree of human development. Numerous conventional treatment approaches including chemotherapy, surgery, radiotherapy, immunotherapy, and hormonal therapies have significant limitations, and patients face unfavorable outcomes. Therefore, these treatment approaches necessitate a continuous exploration of novel treatment modalities to minimize the existing limitations including the side effects and toxicities of treatment modalities. In this regard, phytochemicals are getting significant interest because of their capacity to target numerous molecular pathways involved in cancer development without any toxicity. Dietary antioxidant phytochemicals are present in abundance in plants representing different classes of compounds, which exhibit various mechanisms of actions on all stages of tumors. Several preclinical studies reported a significant role of phytochemicals in cancer prevention, whether obtained through a regular diet abundant in fruits and vegetables or via supplements designed to provide the necessary daily dose of active phytochemicals. This book chapter covers an in-depth analysis of preclinical and clinical studies of phytochemicals in cancer treatment, major preclinical findings, clinical trial outcomes, and the potential integration of these phytochemicals into mainstream oncology practices.