Tejaswini Bhavar*
Sonal Bhatkar
Rutuja Rathod
Cancer remains one of the leading causes of morbidity and mortality worldwide, accounting for nearly ten million deaths annually and imposing a substantial socioeconomic burden on healthcare systems and societies at large [1]. Conventional therapeutic approaches such as surgery, chemotherapy, and radiation therapy have significantly improved survival outcomes over the past decades; however, these modalities are often associated with considerable limitations. Chemotherapy and radiation lack specificity, frequently causing damage to normal proliferating tissues and leading to systemic toxicities, while surgical interventions remain viable only for localized tumors and offer limited benefit in advanced or metastatic disease [2]. Furthermore, the emergence of treatment resistance, tumor heterogeneity, and the inability of many cytotoxic agents to completely eradicate minimal residual disease underscore the need for more precise and durable therapeutic strategies [3]. Against this backdrop, the field of cancer immunotherapy has emerged as a transformative paradigm in oncology. Immuno-oncology harnesses the endogenous capacity of the immune system to recognize and eliminate malignant cells, offering a more targeted and sustainable approach to cancer treatment [4]. Unlike traditional cytotoxic therapies, immunotherapy leverages immune memory, enabling long-term tumor surveillance and reducing the likelihood of relapse. The demonstration that tumors can actively suppress immune responses through inhibitory pathways such as PD-1/PD-L1 and CTLA-4 provided the biological foundation for immune checkpoint inhibition and marked a turning point in therapeutic innovation [5]. Historical milestones in immuno-oncology span over a century of scientific exploration, beginning with William Coley’s early attempts at stimulating antitumor immunity using bacterial toxins in the late 19th century [6]. These initial observations laid the groundwork for understanding the relationship between the immune system and cancer. The subsequent development of the cancer immunosurveillance and immunoediting hypotheses provided crucial insights into how tumors evade immune detection and shaped the modern conceptual framework of tumor immune dynamics [7]. The introduction of interleukin-2 therapy in the 1980s, followed by the approval of ipilimumab the first immune checkpoint inhibitor in 2011, represents significant clinical milestones that established immunotherapy as a mainstream oncological treatment [8]. Today, advances such as CAR-T cell therapy, oncolytic viruses, and neoantigen-based vaccines continue to expand the therapeutic landscape and demonstrate the vast potential of immune-based interventions. The objective of this review is to provide a comprehensive examination of the principles, mechanisms, therapeutic modalities, and clinical applications of immuno-oncology, while highlighting recent advancements and ongoing challenges in the field. The review aims to synthesize current scientific evidence, evaluate the impact of immunotherapies across various cancer types, and discuss emerging directions that may shape the future of cancer treatment. By integrating mechanistic insights with clinical outcomes, this paper seeks to contribute to a deeper understanding of how the immune system can be effectively harnessed to combat cancer.
10.5281/zenodo.18056367