Week 1 Flashcards
What is cancer?
A group of diseases characterised by unregulated cell growth and invasion and spread of cells from the site of origin to other sites in the body.
What factors can help distinguish characteristics of a cancer?
The tissue of origin
Name some ways to prevent cancer (lifestyle).
- Don’t smoke
- Keep a healthy weight
- Be safe in the sun
- Avoid certain substances at work
o (Asbestos) - Protect against infections
o (HPV and H.pylori) - Drink less alcohol
- Eat a high fibre diet
- Avoid un-necessary radiation
o (Including radon gas and x-rays) - Cut down on processed meats
- Avoid air pollution
- Breastfeed if possible
- Be more active
- Minimise hormone replacement therapy use
What does a person’s risk of developing cancer depend on?
Age, genetics, exposure to risk factors etc.
What is the largest cause of cancer in the UK?
Smoking
Why has cancer overtaken heart disease as the main killing disease?
Cancer is a disease of the elderly and life expectancy has increased in recent years.
What influences incidences and trends of cancer in recent years?
Risk factors and prevalence in past years.
Describe how the number of cases and mortalities due to Melanoma have altered in recent years and explain why.
Cases of Melanoma have increased due to lifestyle changes such as sunbeds use etc.
However, mortality rates of Melanoma have decreased due to success with immune check-point inhibitors!!! These are extremely successful and often cause remission in stage 4 Melanoma.
What kind of medications are often successful in treating Melanoma?
Check point inhibitors
How have the chances of surviving cancer changed in recent years and why?
• In addition to better treatment options, diagnosis at an earlier stage of a cancer’s development is associated with improved outcomes and increased survival chances.
How can early diganosis of cancer be improved?
Early diagnosis can be improved through reducing cancer waiting times, such as the time waited to see a specialist after an urgent referral from a GP, or the time waited for diagnostic tests.
It can also be improved through public health interventions, such as screening programmes and education campaigns.
What are the different categories of risk factors for canceR?
Biomedical
Lifestyle
Environmental
Name some biomedical risk factors for cancer and suggest which type of cancer they may cause.
- Genetic Susceptibility (cancer of the breasts, ovaries and bowels).
- Hormonal factors in females (cancers of the breast, ovary and endometrium).
Name some lifestyle risk factors for cancer and suggest which types of cancer they may cause
- Smoking (lung, stomach, liver, cervix)
- Alcohol consumption (oral cavity, pharynx, larynx, bowel, liver etc).
- Physical inactivity and obesity (kidney, colon, oesophagus).
- Chronic infections (cervix and liver).
- Diet (bowel, breast, prostate).
Name some environmental risk factors for cancer and suggest which types of cancer they may cause.
- Sunlight (melanoma of the skin and non-melanomal skin cancer).
- Radiation (leukaemia, cancers of the breast and thyroid)
- Occupational exposure (mesothelloma and cancer of the naval cavity).
- Poluution (skin, lung, bladder).
Name some of the risk factors for stomach cancer.
- Age (60-80)
- Helicobactor vylori
- Tobacco
- Being overweight
- Smoked/ salted food
- Family history
In terms of the TNM staging system, what does the letter T describe and what are the divisions of this category?
T refers to the size of the cancer and how far it has spread to nearby tissue.
It can be 1,2,3 or 4. 1 being small and 4 being large.
In terms of the TNM staging system, what does the letter N describe and what are the divisions of this category?
N refers to whether the cancer has spread to the lymph nodes. It can be between 0 (no lymph nodes containing cancer cells) and 3 (lots of lymph nodes containing cancer cells).
In terms of the TNM staging system, what does the letter M describe and what are the divisions of this category?
M refers to whether the cancer has spread to other parts
0 = the cancer hasn’t spread
1 = the cancer has spread
Describe stage 0 of cancer.
Carcino in situ - early form.
Describe stage 1 of cancer.
usually means that a cancer is small and contained within the organ it started in
- Localized
Describe stage 2 of cancer.
usually means that the tumour is larger than in stage 1 but the cancer hasn’t started to spread into the surrounding tissues. Sometimes stage 2 means that cancer cells have spread into lymph nodes close to the tumour. This depends on the particular type of cancer
Describe stage 3 of cancer
usually means the cancer is larger. It may have started to spread into surrounding tissues and there are cancer cells in the lymph nodes nearby.
Describe stage 4 of cancer
means the cancer has spread from where it started to another body organ. For example to the liver or lung. This is also called secondary or metastatic cancer
- Metastasized
What is secondary cancer?
When cancer has metastasized from its original origin and has moved to other areas of the body.
Why is it unlikley to find a cure for cancer?
There are different classifications and types of cancer originating in different tissues with different characteristics and mechanisms. Too difficult to target with one drug.
What are the 6 major categories of cancer?
Carcinoma Sarcoma Myeloma Leukemia Lymphoma Mixed Types
Name the ways in which cancer is classified.
2 ways:
- Type of tissue in which the cancer originates (histological type)
- Primary site, or the location in the body where the cancer first developed
Define carcinoma
A malignant neoplasm of epithelial origin or cancer of the internal or external lining of the body.
What are the 2 major subtypes of carcinoma?
Adenocarcinoma
Squamous cell carcinoma
Where does an adenocarcinoma generally occur and develop?
Usually occur in the mucus membranes and develop in an organ or gland.
What do adenocarcinomas first look like?
Seen as thickened plaque-like white mucosa.
Where do adenocarcinomas spread to?
Spread easily through soft tissues of the body.
Where do squamous cell carcinomas originate?
In the squamous epithelium.
Where do most carcinomas affect?
Organs or glands capable of secretion.
Where is epithelial tissue found?
Epithelial tissue is found throughout the body. It is present in the skin, as well as covering the lining of organs and internal passageways, such as the GI tract
Why are cancers likely to be frequently found in epithelial tissues ?
Epithelial cells are constantly replicating and dividing so are ideal sites for tumour growth.
What is a sarcoma?
A cancer that originates in supportive and connective tissues such as bones, tendons, cartilage, muscle and fat.
In what type of people are sarcomas most common?
Young adults
Describe the appearance of Sarcomas.
Usually resemble the tissue in which they grow.
What is myeloma?
Cancer that originates in the plasma of cells of the bone marrow.
What is Leukaemia ?
Cancer of the bone marrow.
Describe changes in the blood composition of patients with Leukaemia and what consequences are caused?
Often associated with the overproduction of immature white blood cells. These immature white blood cells do not perform well and mean that patients are prone to infection.
Red blood cells are affected and often results in poor blood clotting and fatigue due to anaemia.
What is the technical name for the group of ‘liquid cancers’?
Leukaemia
Where do lymphomas develop?
Lymphomas develop in the glands or nodes of the lymphatic system, a network of vessels, nodes, and organs (specifically the spleen, tonsils, and thymus) that purify bodily fluids and produce infection-fighting white blood cells, or lymphocytes.
Are lymphomas solid or liquid?
Solid
Are leukaemias solid or liquid?
Liquid
What are the 2 sub categories of lymphoma?
Hodgkin lymphoma and non-hodgkin lymphoma
Why may cancers named by their primary site not be accurate?
Cancers named by primary site are not accurate because they do not state the type of tissue involved. Simply indicates where the cancer is located.
What are the hallmarks of cancer?
Sustaining proliferative signalling.
Evading growth suppressors.
Activating invasion and metastasis.
Enabling replicative immortality.
Inducing angiogenesis.
Resisting cell death.
What is meant by the term ‘hallmarks of cancer’?
The hallmarks of cancer comprise six biological capabilities acquired during the multistep development of human tumors.
Describe what is meat by growth signal autonomy and how mutations mean this process is affected within mutations.
Normal cells need external signals from growth factors to divide. But acquired mutations in cancer cells circumvent this and this leads to uncontrolled growth.
Many cancers also develop the ability to produce growth factors.
What are oncogenes?
Genes that promote autonomous cell growth in cancer.
How are oncogenes derived and what do they do?
Oncogenes are derived by mutations in proto-oncogenes and are characterised by the ability to promote cell growth in the absence of normal growth-promoting signals.
What are the products of oncogenes and how are they different from the normal products of proto-oncogenes?
Oncoproteins resemble normal products of proto-oncogenes except that oncoproteins are devoid of important regulatory elements and their production in transformed cells does not depend on growth factors or other external signals.
How is growth signalling altered within cancer cells?
Normally growth factors are made by one type of cell in order to act on another type of cell. Cancer cells can acquire the ability to create and secrete their own growth factors which stimulates a feedback loop in which more cancer cells can divide and so on.
How many growth factor reception be altered in cancer cells?
Cancer cells can have mutations in growth factor receptors. A larger number of receptors are present on the surface of cancer cells. Cancer cells become hyper-responsive to ambient levels of growth factor. Cells are constantly signalled to grow and divide.
By what mechanisms is growth in cancer cells different than normal cells?
Cancer cells can alter the level of growth signal produced. Produce excessive growth signal via a positive feedback loop.
Over-expression of growth factor receptors.
Structural alteration of growth factor receptors.
How may structural alteration of growth factor receptors lead to tumour formation?
The growth factor receptors could be structurally altered, lacking regulatory regions which result in them being permanently ‘turned on’. Constantly signalling for cells to grow and divide.
What is the most common gene in human cancer?
Mutant Ras
Describe how cancer cells evade growth inhibitory signals and describe the effects this has
Most normal cells respond to inhibitory signals to maintain homeostasis, placing cells in G0.
Some cells permanently exit the cell cycle, moving to a post-mitotic state and will not divide again.
In most cells antigrowth factors block cell growth by cellular quiescence through G0 or by using the post-mitotic state. H
However, acquired mutations in cancer cells can remove this block to allow cell growth to continue.
What are the 2 methods that antigrowth factors use to block cell growth in healthy cells?
Cellular quiescence though G0
Using the post-mitotic state
What causes cyclins to be produced?
Growth factors
What is the main function of cyclins?
Once cyclins are produced in response to growth factors, they bind and activate CDKs. CDKs then release transcription factors.
How does retinoblastoma work and what is it?
Retinoblastoma is a tumour supressor protein.
During the G1/S checkpoint, cells monitor their microenvironment to choose whether to continue in the cell cycle and enter G0 or enter a post-mitotic state.
Any antigrowth signals that may be used at this stage are funnelled through the Retinoblastoma protein.