2.3.5 Cancer

Types of Tumours:

1. Benign Tumours:

• Benign tumours are growths of cells that remain confined to one place, typically within a membrane.
• Characteristics:
• Not cancerous: Benign tumours do not invade other tissues or spread to other parts of the body.
• Growth: They grow until they run out of space, but do not usually cause harm unless they press on or damage nearby organs.
• Potential Danger: Although benign tumours are not cancerous, they can be dangerous if they exert pressure on vital organs, such as the brain.

2. Malignant Tumours:

• Malignant tumours are cancerous and have the ability to grow and spread to other tissues in the body.
• Characteristics:
• Cancerous: Malignant tumours invade neighbouring tissues and can spread to distant parts of the body.
• Metastasis: The tumour may break apart, allowing cancer cells to be carried in the bloodstream or lymphatic system to other organs, where they can form secondary tumours.
• Aggressive Growth: Cancer cells in malignant tumours divide more rapidly and live longer than normal cells, making the cancer more difficult to control.

Risk Factors for Cancer:

Lifestyle Risk Factors:

• Smoking: Increases the risk of various cancers, including lung, mouth, bowel, stomach, and cervical cancer.
• Obesity: Linked to higher chances of developing bowel, liver, and kidney cancer.
• UV Light Exposure: Prolonged exposure to ultraviolet (UV) light, such as from the sun or tanning beds, raises the risk of skin cancer.
• Viral Infections: Certain viral infections can increase the risk of cancer. For example, hepatitis B and C can lead to liver cancer, and the human papillomavirus (HPV) is associated with cervical cancer.

Genetic Risk Factors:

• Inherited Genes: Some individuals inherit specific genes from their parents that increase their likelihood of developing cancer. For example, mutations in the BRCA1 and BRCA2 genes are linked to a higher risk of breast and ovarian cancers.