Expert reviewed • 08 January 2025 • 4 minute read
Cancer comprises a set of diseases characterised by uncontrolled cell growth and spread. Unlike other non-infectious diseases, cancer involves fundamental changes in cellular regulatory mechanisms.
Normal cells may become cancerous through DNA damage and failed repair. Over time, they accumulate mutations that grant them growth advantages, resist cell death, and eventually invade other tissues.
Key hallmarks include sustained growth signals, evading growth suppressors, resisting apoptosis, enabling limitless replication, inducing angiogenesis, and acquiring invasive properties that lead to metastasis.
Genetic alterations drive cancer. Oncogenes promote uncontrolled growth, while tumour suppressor genes like p53, when inactivated, fail to halt aberrant cell cycles. Metabolic changes and disrupted signalling pathways further distinguish cancer cells.
Physical factors (UV, ionising radiation) and chemical carcinogens (asbestos, tobacco smoke, certain pollutants) contribute to mutational loads. Chronic inflammation and persistent exposures heighten cancer risk.
Primary prevention includes lifestyle modifications and reduced exposure to carcinogens. Secondary prevention involves regular screening programs (mammography, Pap smears, colonoscopy) to detect early changes, improving treatment outcomes.
Traditional treatments involve surgery, radiation, and chemotherapy. Emerging therapies—like immunotherapy, gene therapy, and targeted treatments—hone in on specific tumour characteristics. Precision medicine tailors interventions to genetic profiles, while early detection and novel prevention strategies improve survival rates.