Oncology Flashcards
What is a neoplasm?
A mass of tissue that grows faster than normal in an uncoordinated manner
What is a tumour
- Literally means ‘swelling’ (Latin)
- Now primarily used to describe a mass / growth of tissue.
- This growth can be either malignant or benign.
Explain why developed countries display higher cancer rates.
This emphasises the link to environment, lifestyle, diet, medications
and drugs.
Discuss the following statement:
‘Cancer is the result of underlying causes’.
Cancer is the result of underlying cause.
The underlying cause of cancer ultimately promote the mutations of multiple genes but it is not the mutations of multiple genes that cause the cancer.
This is where it is essential to explore the interaction of the patient’s genes with the environment.
Explain the role of ‘oncogenes’ in the development of cancer.
Tumour suppressor genes become inactivated and new genes called oncogenes are formed that cause overproduction of growth factors and increase cell division
Explain what is meant by ‘angiogenesis’.
Formation of new blood vessels
Describe 3 terrain environments that allow cancer cells to thrive:
Acidic environment
Red meats, processed foods, dairy, sugar, salt and smoked foods add to the acidity of the body.
Cancer cells thrive in acidity
Anaerobic environment
Lacking oxygen - Stress, breathing, diet, exercise.
Glucose-rich environment
Malignant cells are dependent on glucose for their own metabolism. These cells have many more glucose receptors on their membrane.
Explain the relationship between ‘contact inhibition’ and cancerous cells.
Cancerous cells lose contact inhibition.
Proteins are normally produced by cells which give it contact inhibition that prevents them from dividing beyond the space available.
Define mutation.
The change in the genetic information.
(change in DNA sequence / number).
List FOUR mutagenic agents.
A mutagenic agent in an agent that changes the genetic information.
Mutagens can be:
- Radiation – X-Rays, microwaves, mobile phones
- Chemicals – environmental, household, drugs, vaccines
- Environmental hazards
- Viruses
- Inflammation
- Defective Immunity
- Stress/emotional trauma
Describe how the following factors could increase the risk of cancer:
a. Chronic inflammation:
b. Smoking
c. Gastrointestinal dysfunction
d. Chronic stress
e. Alcohol
f. Obesity
g. Red meats
h. Low fibre
i. Refined sugar
j. Diary
k. Immune suppression
Chronic inflammation:
* promotes proliferation of cancer cells.
* inflammatory bowel diseases, gastro-oesophageal reflux disease, gastritis, etc
Smoking
Causes one mutation every 15 cigarettes
Gastrointestinal dysfunction
* liver (detoxifies substances)
* Intestines (excrete body wastes, absorb nutrients and immune function).
Chronic stress
Elevates cortisol levels which would suppress the immune system.
Alcohol
e.g. for mouth, oesophageal, breast and colorectal).
Obesity
Excess body fat changes hormone metabolism»> higher oestrogen »> drives oestrogen-positive tumours
e.g. breast cancer in post-menopausal women
Red meats
* Especially for colorectal, prostate, bladder, breast, gastric and pancreatic cancers
* Higher risk if charcoal cooked / smoked and at high temperatures
Low fibre
* Fibre is high in phytochemicals;
* clears toxins and hormones (e.g. oestrogen) through the bowel.
Refined sugar
* Feeds cancer cells and promotes growth
* Increases acidity with promotes cancer cell growth
Diary
* Pro-inflammatory
* Contains IGFs (insulin- like growth factors) that promote tumour growth.
Immune suppression
Chronic immunodeficiency can increase the risk for cancer.
* Cytotoxic T-lymphocytes, NK cells and macrophages are needed to destroy abnormal cells.
* HIV targets CD4 cells (T-helper cells and macrophages), which, therefore, compromises the host immune system.
- A healthy, functioning immune system is essential to providing support against malignant cell development.
Describe THREE key differences between ‘benign’ and ‘malignant’ tumours
Cells
Benign:
*differentiated
* appear similar to normal cells
* may be functional.
Malignant:
* undifferentiated
* non- functional cells
* varied shapes and sizes and large nuclei
Growth/Reproduction
Benign: Grows very slowly and does not spread
Malignant: Cells reproduce much faster than normal
Spread
Benign:
* Very often encapsulated therefore no metastases.
* Systemic effects rare
Malignat:
* Not encapsulated therefore infiltrates other tiisues (metastases).
* Often systemic and can spread very quickly to other organs
Threat to life
Benign: Not life threatening but can result in compression of tissues and intercranial brain pressure
Malignant: Life threatening due to tissue destruction and spread
Using definitions explain the difference between ‘grading’ and ‘staging’ of cancer.
Grading is the measure of the degree of cell differentiation / abnormality from Grade 1 to grade 4.
Staging is the classification of malignant tumours according to the extent of the disease at the time of diagnosis from stage 0-4
What are the grades in cancer
Grading is the measure of the degree of cell differentiation / abnormality. Goes from grade 1 to 4 where
1 is where tumour cells are still similar to original. Cells are differentiated and specialised (i.e., benign tumour).
4 is where tumour cells are undifferentiated with many abnormal cells varying in size and shape.
What are the stages in cancer?
Staging is the classification of malignant tumours according to the extent of the disease at the time of diagnosis
Stage 0 – Pre-cancerous cells
Stage 1 – Cancer limited to tissue of origin
Stage 2 – Limited local spread of cancerous cells
Stage 3 – Extensive local and regional spread
Stage 4 – Distant metastases
Explain the TNM staging system
(Think: T, N, and M).
**T **(1-4) – TUMOUR : Size of primary tumour
N (0-3) – NODE : Degree of lymph node involvement
**M **(0-1) – METASTISIS: 1 Means yes
List TWO local effects of a tumour.
A tumour with no function damages the space it occupies.
How?
- Compress blood vessels leading to necrosis of surrounding tissues.
- Malignant cells do not adhere to each other so they metastasise.
- Pain is not usually an early symptom of cancer. If it occurs, it is caused by pressure or inflammation.
- Obstruction may occur in tubes or ducts in the body.
- Infection - Tissue ulceration / necrosis may produce infection perhaps due to compromised immunity from treatment .
Describe the following systemic effects in cancer:
a. Cachexia
b. Para-neoplastic syndrome
c. Anaemia
d. Infections
a. Cachexia – weight loss and muscle atrophy (hence fatigue and weakness)
b. Para-neoplastic syndrome - Symptoms that occur at site distant from a tumour or metastases because the cancer has a knock on effect.
Eg: lung cancers may produce ACTH leading to excess corticosteroids produced by lung tumour cells and resulting in Cushing’s syndrome
c. Anaemia – malnutrition, bleeding, bone marrow suppression
d. Infection: Host resistance compromised, giving way to infections; e.g. pneumonia.
List TWO ways by which malignant tumours spread in the body.
Blood
Lymph
List FOUR common sites of metastasis in the body.
Often first metastases appear in regional lymph nodes.
- lungs and liver due to venous and lymphatic flow
- bone
- brain.
Discuss the following statement:
‘Tumour markers can provide an absolute diagnosis of cancer’.
Tumour markers found in the blood, urine, stools or tissues must be used within the context of the patient presentation and other clinical findings.
- A tumour marker measures substances (usually proteins) produced by tumours
- Some markers are found in non-cancerous conditions, whilst other tumour markers might indicate a malignancy.
- Some tumour markers are more sensitive / more indicative of some types of cancer; e.g. CA-125 and ovarian cancer.
List ONE blood borne tumour marker which may be elevated in Colorectal cancer
- CEA
- It has a low sensitivity and specificity and so is used more for monitoring than screening or diagnosing
- Other conditions it may be elevated in: Pancreatitis; ulcerative colitis, liver cirrhosis
List ONE blood borne tumour marker which may be elevated in Prostate cancer
PSA
- Used to assist in the diagnosis of prostate cancer, although it often produces false positives.
- PSA testing can be used to monitor tumour progression and metastasis
- May be elevated in benign prostate hyperplasia
Name ONE tumour marker used to diagnose testicular cancer.
- HCG
- Males do no normally produce it
- Used for other cancers – pancreas, pituitary and placenta
Name a tumour marker elevated in Ovarian cancer
CA25
- Elevated in many cases on ovarian cancer
- can use for be monitoring
Name a tumour marker elevated in Breast cancer
CA15-3
- can be used for monitoring
Name ONE stool tumour marker which can be used as a screening method for colorectal cancer.
Stool analysis looks for:
- Occult blood
- M2-PK
