Cancer Flashcards
What is a cancer?
*Cancer is a group of disease (around 200 in total) caused by a growth disorder of cells.
*It is caused by damage to the genes which regulate mitosis and the cell cycle.
*Cancer occurs when cell multiplication is faster than cell death.
*Causes a growth of abnormal cells called a tumour.
*Cancer is more likely to occur in cells with high mitosis rates (e.g. lung, bowel, gut, bone marrow).
What are benign and malignant tumors?
*A tumour becomes cancerous if it changes from benign to malignant.
*Benign tumours - grow more slowly, more compact, less likely to be life threatening, do not spread
*Malignant tumours - grow quickly, less compact, spread via blood/lymphathic system, more likely to be life threatening
What are some causes of cancer?
genetic risks, UV rays from the sun, viruses, carcinogens
How do cancers spread?
*Cells from initial tumour break away (primary cancer).
*Cells travel to another tissue or organ (secondary cancer).
*Spreading = metastasis.
*Cancers can spread in 2 ways:
Circulatory system (blood vessels)
Lymphathic system (tubes/glands that filter body fluid)
What are some of the ways you can treat cancer?
*Usually involves killing dividing cells by blocking a part of the cell cycle.
*This disrupts the cell cycle/division and therefore cancer growth is prevented.
*E.g. Chemotherapy
*Prevents DNA from replicating
*Inhibits metaphase by interfering with spindle formation
What are the problems with current treatments?
*Most treatments (e.g. chemotherapy) cannot distinguish between cancerous and normal cells - they end up disrupting both!
*However, because cancer cells have a higher division rate they are damaged more than normal cells.
*Other fast dividing cells (e.g. hair producing cells) are also likely to be affected - producing characteristic symptoms of these treatments (e.g. hair loss).
