Cancer (Overview)

What it is

Cancer is the uncontrolled clonal proliferation of cells that have acquired enabling driver mutations, escaped immune surveillance, and remodelled their microenvironment. Risk rises exponentially with age, reflecting cumulative mutation burden and immunosenescence.

Why it matters for longevity

Cancer is the second leading cause of death in most high-income countries (closing the gap with cardiovascular disease as the latter falls). Lifetime risk of any cancer is >40% in many populations.

Big modifiable risk factors

• Smoking (lung, head/neck, bladder, etc.).
• Obesity (~13 cancers in IARC list).
• Alcohol (any amount associates with breast, oesophageal, others).
• Ultraviolet exposure (skin cancers).
• Sedentary behaviour.
• Several chronic infections (HPV, HBV, HCV, H. pylori) — vaccination and treatment matter.

Screening with established benefit

• Colonoscopy / FIT for colorectal cancer.
• Mammography for breast cancer (in age-appropriate groups).
• Cervical cytology + HPV testing.
• Low-dose CT for lung cancer in heavy smokers.
• PSA: shared decision-making in older men.

Multi-cancer early-detection (MCED)

Blood-based screens such as Galleri test for shared cancer signals across many sites. Early evidence is promising but limitations include false positives, indeterminate tissue-of-origin signals, and unclear effect on mortality.

Connection to aging biology

Cellular senescence, genomic instability, chronic inflammation, and deregulated nutrient-sensing all feed cancer biology. Many longevity-relevant interventions (metformin, exercise, sleep adequacy, lower IGF-1) also modify cancer risk modestly.

Related entries

Genomic instability, Galleri (clinic), Cellular senescence.