Final answer:
Cancer is a group of diseases with abnormal cell growth and potential to spread. The four most common types are basal cell carcinoma, breast cancer, prostate cancer, and lung cancer. Cancer cells spread via local invasion, lymphatic system, and bloodstream.
Step-by-step explanation:
Overview of Cancer
Cancer refers to a group of more than 100 diseases characterized by abnormal and unregulated cell growth with the potential to invade or spread to other parts of the body. This complex disease occurs when the cell cycle is disrupted due to DNA damage leading to rapid cell division, forming a mass called a tumor, and possibly metastasizing to damage other tissues.
Common Types of Cancer
The four most common types of cancer affecting the adult population are:
- Basal cell carcinoma: A type of skin cancer that is the most prevalent of all cancers and is often curable.
- Breast cancer: The most common cancer among adult females, accounting for about one-third of all female cancers.
- Prostate cancer: Prevalent in adult males and makes up about one-third of all male cancers.
- Lung cancer: The second most common cancer affecting both men and women, primarily linked to smoking.
How Cancer Spreads
Transformed cancer cells can spread from the original tumor site by:
- Local invasion of adjacent tissues
- Lymphatic spread to nearby lymph nodes
- Distal metastasis through the bloodstream to distant organs
Early diagnosis and comprehensive treatment, including surgery, chemotherapy, radiation therapy, and immunotherapy, can improve outcomes for many cancer patients.