Cancer Flashcards
What is cancer defined as
A collection of diseases caused when cells divide uncontrollably and spread into surrounding tissues
What is a carcinoma
a type of cancer that affects epithelial tissue often seen in breasts lungs and livers. It is the most common form of cancer.
What is Sarcoma
A cancer that affects the connective tissue often seen in bones and muscle
what is a hematological malignancy
a type of tumor caused by the disruption of normal hematopoeitic function e.g. myeloma, lymphoma and leukemia
what is myeloma
a type of hematological malignancy that can be seen in plasma cells in the bone marrow tissue
what is leukaemia
a type of hematological malignancy that affects the white blood cells and red blood cells in the bone marrow
If a condition ends in the term oma what does this indicate
lipoma and adenoma are examples of this convention and highlights a benign tumour
what is a benign tumour
stay in their primary location without invading other tissues
what is a malignant tumur
tumors that spread beyond their initial site and are considered more dangerous
define the term neoplasm
a new disorganized growth often related to cancer where there is a net increase in cells.
what is carcinogenesis
the prcess of forming a cancer
what is a proto-oncogene
Genes that normally help cells grow and divide to make new cells and when mutated can cause cells to become cancerous.
What is an oncogene
term given to genes which when mutated or are over expressed can cause cancer.
Describe the phases of the cell cycle
M phase: mitosis and cytokinesis
G0 Resting cells
G1 RNA and protein synthesis req’d for s phase
S phase DNA synthesis
G2 RNA and protein synthesis required for Mitosis and cytokinesis
what are the different parts of M phase
within the mitosis stage before cytokinesis there are 4 stages
Prophase,
metaphase,
anaphase,
telophase
describe the prophase stage
the chromosomes condense while centrosome assemble with the nuclear membrane begins to break down
describe the metaphase stage
the chromosomes align and attach to the spindle
describe the anaphase stage
chromotids pull apart and migrate to poles
describe telophase stage
chromotids de condense and new nuclear membrane forms
describe the four stages of mitosis and what happens during cytokinesis
During prophase the chromosomes condense and the centrosome assemble. The nuclear membrane then begins to break down before metaphase begins.
The chromosomes then align and attach to the spindle as anaphase causes chromotids to pull apart and migrate the chromosomes to poles of the cell
the telophase then occurs which involves the chromotids de condensing and new nuclear membrane forms before cytokinesis
cytokinesis is the act of a contractile pinching and dividing the mother and daughter cell before entering into g0 of the cell cycle.
Describe the 6 hallmarks of cancer
Self sufficiency in growth signals - losing the need for growth factors. This often due to a change in the receptor or signaling pathway.
Insensitivity to growth inhibitors - cells lose the ability to control abnormal cell proliferation which may result from the loss of tumour suppressor genes e.g. pRB or the upregulation of positive cell cycle regulators.
evading apoptosis - under normal conditions it is triggered in cells by dna damage and infection and are avoided through the gain of function of pro survival factors.
limitless replicative potential - under normal conditions cell proliferation limited by telomere length. In tumor cells they can rebuild their telomeres using the enzyme telomerase.
sustained angiogenesis - an increased level of angiogenesis provides blood to the tumor to keep the
tissue invasion and metastasis - metastasis is the spread of he cancer to different sites.
Describe how mutation of the RAS oncogene can lead to continuous cell proliferation
In the presence of growth signals RAS (oncogene) is activated and triggers other signaling events that lead to cell proliferation.
When it is mutated it is switched on all the time leading to a constant proliferation even in the absence of a growth factor
What are some other notable oncogenes
BCR-ABL
myc
SRC
PI3 Kinase
RAS
Name 3 Tumour suppression genes
pRB,p53 BRCA
Explain how cancer can cause us harm
Cancer can cause us harm through 3 methods
Disrupting organ function
Interfering with metabolic processes
Muscle wasting
Cancers can disrupt organ function through obstructing them, depriving them of nutrients or apply unwanted physical pressure
Cancers can disrupt metabolic processes by causing malnutrition or calcium changes,
by disrupting the production of blood cells or hormones
and through interfering with the liver enzyme function
Describe why cancer can take a while to develop
A single mutation is not enough to lead to the progression of cancer
in actuality a cell will need to undergo multiple mutations to gain most of the hallmarks of cancer in order to progress
Define what a mutation is
A mutation is a change that occurs to DNA, there are multiple types of mutation that alter the DNA sequence e.g. point mutation, alteration and deletions
Name the 5 different types of mutation
Point mutations, insertions and deletions can occur in gene coding regions
Alterations in transcription/splicing
Amplification/deletions of chromosomal regions
Chromosomal trasnlocations
DNA modification e.g. methylation
describe what factors can cause mutations
UV + other radiation
Free radicals
Viruses
Chemicals
Repair errors
what cancers are affiliated with the papovavirus family
warts
carcinoma of the uterine cervix
what cancers are affiliated with the hepadnavirus family (hep b and c)
liver cancer
what cancers are affiliated with herpesvirus
burkitts lymphoma
nasopharyngeal carcinoma
what cancers are affiliated with the retrovirus family
t cell leukemia and lymphoma
kaposi’s sarcoma
what are the three stages of cancer
initiation where the first mutations promoting a increased proliferation occurs
promotion in which additional mutations promote further proliferation
initiation and promotion are part of carcinogenesis (process of developing a cancer)
progression which sees the growth and the invasion of a tumour
Describe why survival rates are improving amongst cancer patients
Earlier diagnosis attribute to a higher survival rate through better screening and scanning for biomarkers
Better treatments through surgery,chemo and radiotherapy
what are some risk factors for cancer
smoking
lack of physical activity
obesity
alchohol
diet
infection
