Question

Describe four ways that cancer can originate at the cell or tissue level.

Short answer

Cancer can originate by four methods at the cell or tissue level: genetic mutations, viral induction, chronic inflammation, and changes in cell metabolism.

Step-by-step solution

Genetic Mutations

Cancer can originate due to genetic mutations. These mutations can be hereditary or can happen due to environmental factors such as radiation, chemicals or viruses. They alter the DNA structure within a cell, disrupting normal cell growth and division. An accumulation of mutations can lead to the development of cancer.

Viral Induction

Certain viruses can integrate their DNA into a host cell's DNA – a process called viral integration. This can lead to the deregulation of cell growth and division process, if virus DNA incorporates in crucial cellular pathways, supporting development of cancer. Examples include Human Papilloma Virus leading to cervical cancer, and Epstein Barr virus leading to certain types of lymphomas.

Chronic Inflammation

Long-term inflammation can lead to cancer. Inflammatory cells release substances that cause DNA damage and can result in cancer. For instance, chronic inflammatory bowel diseases such as ulcerative colitis have a higher rate of colonic cancer.

Changes in Cell Metabolism

Changes in normal functioning of cellular metabolism can lead to cancer. Normal cells, for instance, require oxygen for metabolic processes, but some cancer cells alter these processes to survive in low oxygen environment contributing to uncontrolled cell proliferation.