#5 Introduction to cancer and cancer biology Flashcards
(14 cards)
What is cancer?
Cancer is a collection of diseases characterized by uncontrolled cell growth, caused by DNA changes. Multiple genetic changes are usually required to develop cancer.
What is the cancer risk in the UK?
1 in 2 people born after 1960 will be diagnosed with cancer. Around 40% of cases are preventable through lifestyle changes.
Which infections cause cancer?
Viruses cause 10–15% of cancers (e.g., HPV). Chronic infections and weakened immune surveillance can contribute to tumor development.
How does cancer spread?
Cancer can invade surrounding tissues and metastasize to other parts of the body via the bloodstream or lymphatic system.
How can people reduce cancer mortality?
By raising awareness, encouraging early symptom recognition, and promoting healthy lifestyle choices to lower cancer risk.
What is cancer screening?
Screening identifies early-stage cancers in asymptomatic people (e.g., breast, colorectal, cervical cancers) to improve outcomes.
What are the main cancer treatments?
Surgery: Removes localized tumors, often the best option for a cure.
Radiotherapy: Uses ionizing radiation to destroy cancer cells.
Chemotherapy: Uses drugs to kill cancer cells, often in cycles.
Immunotherapy: Helps the immune system attack cancer cells.
What are cancer grade and stage?
Grade: Describes how abnormal cancer cells look (e.g., Gleason grade).
Stage: Indicates tumor size and spread using the TNM system:
T: Tumor size
N: Lymph node involvement
M: Metastasis presence
What causes DNA damage leading to cancer?
Inherited predisposition
Chemical agents (e.g., tobacco)
Radiation (e.g., radon gas)
Infections and chronic inflammation
Random chance (e.g., cell division errors)
How does smoking affect cancer risk?
Smoking causes 30–40% of cancer deaths, not just lung cancer, but many other types too.
How does cancer metastasize?
Cancer cells break off from the primary tumor, travel through blood or lymph, and settle in new areas to form secondary tumors.
How does obesity increase cancer risk?
Fat tissue produces hormones and growth factors that can influence cell behavior. Obesity is linked to cancers like breast, bowel, and pancreatic.
How does cancer kill?
Cancer can block organs, cause bleeding, and overwhelm the body through metastasis. A metastatic burden of ~1kg can lead to death.
What are oncogenes and tumor suppressor genes?
Oncogenes: Mutated genes that drive cancer growth.
Tumor suppressor genes: Regulate cell growth. When inactivated, cancer risk increases.
