Cancer Initiation and Progression: A Comprehensive Review of Carcinogenic Substances, Anti-Cancer Therapies, and Regulatory Frameworks

Cancer is a multifaceted disease influenced by genetic mutations and environmental factors, including exposure to carcinogens. This review presents an in-depth analysis of the mechanisms driving cancer initiation, focusing on the roles of carcinogenic chemicals, anticancer therapies, and chemo-preventive agents. The discussion encompasses a broad spectrum of carcinogens: chemical agents like polycyclic aromatic hydrocarbons, physical agents such as ionizing radiation, biological agents like viruses, and certain therapeutic drugs. The multistep nature of carcinogenesis—comprising initiation, promotion, and progression phases—is detailed, with an emphasis on genetic and epigenetic alterations. Methods for testing carcinogenicity, including in vitro and in vivo studies and epidemiological approaches, are highlighted for their significance in identifying potential carcinogens and understanding their mechanisms. To classify and regulate carcinogenic exposures, the review also looks at the risk management plans and regulatory frameworks used by agencies like the European Chemicals Agency (ECHA), the Environmental Protection Agency (EPA), and the International Agency for Research on Cancer (IARC). Additionally, emerging trends in cancer treatment, such as precision oncology, immunotherapy, and early detection technologies, are explored, alongside ongoing challenges like health disparities and ethical issues. The review emphasizes the necessity of a multidisciplinary approach, involving collaboration among researchers, clinicians, regulatory bodies, and public health organizations, to translate scientific findings into effective cancer prevention, detection, and treatment strategies.