Cancer Overview and Global Burden

Cancer Overview

• Cancer is a group of diseases characterized by abnormal cell growth.
• Cells can spread (metastasize) from the primary site to other parts of the body.
• Tumour growth depends on nutrient and oxygen delivery, facilitated by angiogenesis (new blood vessel formation).

Global Cancer Burden

• Approximately 18.1 million new cancer cases and 9.6 million deaths occur annually.
• One in five (20%) men and one in six (17%) women develop cancer during their lifetime.
• One in eight men and one in eleven women die of cancer.
• Worldwide, the five-year prevalence is approximately 43.8 million.

Cancer in Asia

• Asia accounts for nearly 60% of the global population and a large proportion of new cancer cases and deaths.

UK Cancer Rates

• The UK ranks 13th globally in cancer rates.
• Approximately 367,000 new cases and 165,000 deaths occur annually in the UK.
• Breast, prostate, lung, and bowel cancers make up more than 50% of all new cases.
• 36% of diagnosed cancers are in people aged 75+.
• 50% of cancer patients survive for 10 years or more.

Tumour Types (Benign vs. Malignant)

• Benign: Cells do not invade surrounding tissue and do not metastasize. Often encapsulated and resemble the original tissue type. Relatively harmless.
• Malignant: Cells invade and metastasize to distant sites. 85% are carcinomas (epithelial cells). Can be leukemias or lymphomas (liquid). Poorly differentiated and fast-growing, resulting in poor outcomes.

WHO Global Cancer Incidence (2018)

• Africa: 5.8%
• The Americas: 21%
• Europe: 23.4%
• Oceania: 1.4%
• Asia: 48.4%

Survival Rates (Five-Year Survival)

• Data shows varying survival rates for different cancer types (e.g., lung, bowel, stomach, pancreas) across different countries.

Cancer Classification

• Carcinoma: Most common, arising from endoderm or ectoderm cells (e.g., lung, breast, colon).
• Sarcoma: Arises from mesoderm cells (e.g., bone, cartilage, fat, muscle).
• Lymphoma: Cancers arising in lymph nodes and immune tissues.
• Leukemia: Immature white blood cell cancers that develop in bone marrow and circulate in the bloodstream.

Cancer Causes

• Tobacco; Body weight; Physical inactivity
• Diet; Hormones; Sunlight
• Occupational carcinogens; Infectious agents (e.g., viruses, bacteria); Medical treatments
• Pollution; Genetic factors.

Cancer Symptoms

• Often asymptomatic in early stages.
• Symptoms vary depending on the specific cancer type (e.g., lung cancer: cough, chest pain, breathlessness; pancreatic cancer: weight loss, stomach/back pain; breast cancer: lump, size changes, discharge).

Metastasis Cascade

• Migration: Cells move away from primary site.
• Intravasation: Cells enter the circulatory system.
• Survival: Cells navigate through circulation.
• Arrest at distant site: Cells adhere to target tissue.
• Extravasation: Cells leave the circulatory system.
• Growth of secondary tumour.
• Colonization: Formation of a new tumour mass. (A series of events leading to dispersal, survival, and establishment of secondary tumors)

Angiogenesis

• The formation of new blood vessels, crucial for tumour growth beyond 1mm³.
• Tumours often hijack normal blood vessel development using growth factors.
• Normal angiogenesis is tightly regulated, whereas pathological angiogenesis has a less organised and more unstable blood vessel morphology.

Hallmarks of Cancer

• Key characteristics enabling cancer development, including resisting cell death, inducing angiogenesis, and evading growth suppressors.