The protective role of carotenoids and polyphenols in patients with head and neck cancer.

Head and neck cancer is a critical global health problem and approximately 650,000 patients per year are diagnosed with this type of cancer. In addition, head and neck cancer exhibits a high recurrence rate, readily causing second primary cancers in other locations, often yielding a poor prognosis. Current medical and surgical treatment options result in considerable impairment of speaking and swallowing functions, with side effects such as nausea, vomiting, bone marrow suppression, and renal damage, thereby impairing patients' quality of life. Thus, developing a prevention and therapeutic intervention strategy for head and neck cancer is vital. Phytochemicals have been shown to have a unique ability to protect cells from damage and modulation of cell repair. The chemopreventive activities of phytochemicals have also been demonstrated to be associated with their antioxidant properties and the induction and stimulation of intercellular communication via gap junctions, which play a role in the regulation of cancer cell cycle, differentiation, apoptosis, and stagnate cancer cell growth. Phytochemicals can also regulate cancer cell signaling pathways, reduce the invasion and metastasis of cancer cells, and protect normal cells during treatment, thus reducing the damage caused by chemotherapy and radiotherapy. The most studied of the chemopreventive effects of phytochemicals are the carotenoids and phenolics. In this review, we investigated the multiple mechanisms of carotenoids and polyphenols (PPs) for use in preventing head and neck cancer, reducing the side effects of chemotherapy and radiotherapy, improving patient survival rates, and reducing the occurrence rate of second primary cancers.