Reviewing the Concepts of Immune Surveillance of Cancer Cells, Immunogenic Cancer Cell Death and the Role of Medicinal Plants in Anticancer Immunity

Current standard treatment of cancer usually involves surgical resection, chemotherapy and radiotherapy. Surgical resection is aimed at eliminating the primary tumour from its anatomical site of origin, while chemotherapy and radiotherapy are meant to target metastatic tumour cells around the primary tumour site and distant parts of the body. Although standard treatment of cancer usually produces some initial positive clinical responses, such responses are often followed by recurrence of malignancy, several months or years later. Consequently, efforts are currently being focused on stimulating a patient’s natural immune responses, to fight against metastasized cancer cells that are mainly responsible for cancer relapse. The role of the immune system in the prevention and treatment of cancer has long been established. In fact, a patient’s response to chemotherapy and radiotherapy has been observed to be largely dependent on the level of competence of the immune system. Despite these observations, little effort is currently being made to boost a patient’s immune response during cancer treatment. The confidence and consequent use of medicinal plants for treatment of many disease conditions is currently growing rapidly and many of these medicinal plants have been observed to possess anti-neoplastic, anti-malignant, immune-stimulatory, and cytoprotective effects, which can all be harnessed, to produce better outcomes for cancer treatment. This review therefore seeks to reawaken the interest of researchers, pharmaceutical giants, clinicians and scientists in investigating and validating the potential use of extracts of medicinal plants as valuable components in the management and treatment of cancer.