44. Cancer: Benign & Malignant Tumours

Cancer is a disease caused by the uncontrolled growth and spread of abnormal cells. To understand cancer, it is essential to distinguish between the different types of tumors that can form in the body.

1. Benign vs. Malignant Tumours

A tumour is an abnormal mass of cells resulting from uncontrolled cell division. They are categorized based on their behavior:

• Benign Tumours:

  • The growth of abnormal cells is contained within one area, usually inside a membrane.

  • They do not invade other parts of the body.

  • Generally, they are not considered cancerous or life-threatening.

• Malignant Tumours:

  • The cells are not contained and can invade neighboring tissues.

  • Cells can break off and travel through the bloodstream to other parts of the body.

  • They form secondary tumours in different organs.

  • These are classified as cancer and are significantly more dangerous and potentially fatal.

2. Lifestyle Risk Factors

Certain behaviors and environmental exposures are strongly linked to an increased risk of developing various cancers:

• Smoking: Highly linked to lung cancer, but also increases the risk of mouth, stomach, and cervical cancers.

• Obesity: Associated with an increased risk of bowel, liver, and kidney cancers.

• UV Exposure: Ultraviolet light from the sun or tanning beds damages skin cells, leading to skin cancer.

• Alcohol: Consumption is a known risk factor for liver cancer.

3. Genetic Risk Factors

Not all risk factors are within an individual's control. Genetics play a significant role in susceptibility:

• Inherited Genes: Some people inherit specific genes from their parents that make them more likely to develop certain types of cancer.

• Example: Mutations in the BRCA genes are strongly linked to an increased risk of breast and ovarian cancer.

Summary Table: Tumour Comparison