Definition of cancer in biology
Pro Research Analysisby 
Searched over 200M research papers
Consensus Meter
Understanding the Definition of Cancer in Biology
Cancer as a Disease of Uncontrolled Cell Growth
Cancer is fundamentally characterized by the uncontrolled proliferation of cells. This definition aligns with the National Cancer Institute's description: "Cancer is a disease in which some of the body's cells grow uncontrollably and spread to other parts of the body". This uncontrolled growth is a hallmark of cancer, distinguishing it from normal cellular processes.
Genetic Basis of Cancer
Cancer is widely recognized as a genetic disease. It involves multiple genetic mutations that drive the transformation of normal cells into malignant ones. These mutations can affect oncogenes and tumor suppressor genes, leading to the progressive growth and disorganization of cells . The genetic alterations are often specific to particular types of cancer, such as lung, colon, and breast cancers, where consistent chromosome aberrations are observed.
Evolution and Transformation of Cancer Cells
Modern definitions of cancer emphasize the evolutionary aspect of the disease. Cancer cells are not only proliferating uncontrollably but are also subject to evolution by natural selection. This means that cancer cells undergo genetic and epigenetic changes that enhance their survival and proliferation capabilities. This evolutionary perspective helps explain the complexity and adaptability of cancer cells.
Multistep Nature of Cancer Development
The development of cancer is a multistep process requiring several mutations. Each mutation contributes to the gradual increase in tumor size, disorganization, and malignancy. Typically, three to six mutations are necessary to complete the transformation from a normal cell to a fully malignant one. This multistep nature underscores the complexity of cancer development.
Role of Viruses in Cancer
There is a historical perspective that some cancers may be caused by viral infections. Certain viruses can integrate into the host's genetic material, leading to cellular transformations that result in cancer. However, this view is not universally accepted, and the majority of cancers are attributed to somatic mutations rather than viral infections .
Molecular Mechanisms and Hallmarks of Cancer
Cancer involves a complex interplay of various molecular mechanisms, including DNA repair, cell-cycle control, apoptosis, and tissue invasion. These processes are driven by changes in gene expression and the local cellular environment. The "hallmarks of cancer" framework distills this complexity into key principles, such as sustained proliferative signaling, evasion of growth suppressors, and resistance to cell death.
Conclusion
In summary, cancer is a multifaceted disease characterized by uncontrolled cell growth, genetic mutations, and evolutionary processes. It involves a complex interplay of molecular mechanisms and can be influenced by both genetic and environmental factors. Understanding these aspects is crucial for developing effective diagnostic and therapeutic strategies.
Sources and full results
Most relevant research papers on this topic