Cancer is a genetic disease caused by accumulated mutations in DNA that disrupt normal cell growth, division, and repair. These genetic changes, either inherited or acquired via environmental factors (like smoking/UV rays) and random errors, activate growth-promoting oncogenes and inactivate tumor suppressor genes, leading to uncontrolled cell proliferation.
Key aspects of the genetic basis of cancer include: Driver Mutations: Cancer arises when cells accumulate mutations over time, turning healthy cells into malignant ones.
Oncogenes (“Stuck Accelerator”): Normal genes (proto-oncogenes) that encourage cell growth become mutated into oncogenes, causing cells to divide continuously.
Tumor Suppressor Genes (“Broken Brake”): These genes normally prevent cancer by regulating cell division or repairing DNA. When inactivated (e.g., p53, BRCA1/2), cells fail to stop dividing, often leading to tumor growth.
Epigenetic Changes: Alterations in gene expression (such as methylation) that do not change the DNA sequence but can silence tumor suppressors.
Inherited vs. Acquired: While most mutations are acquired (somatic) throughout life, some are inherited (germline), increasing susceptibility to certain cancers.
