Neoplasia and cancer

Question 1

What is neoplasia?

Answer 1

Abnormal, mass tissue, the growth of which exceeds and is uncoordinated with that of normal tissue and persists in the same excessive manner after cessation of the stimuli which evoked the change.

Question 2

Describe features that distinguish benign and malignant tumours

Answer 2

Benign
Non-cancerous cell
Grow slowly
few mitoses
They don't metastaisze(spread) 
Tend to have a good progosis

Malignant
Cancerous cells
Grow rapidly
Many mitoses 
They metastasize (spread)
Poor prognosis if left untreated

Question 3

Define the key hallmarks of cancer cells(not how they look like)

Answer 3

1) They resist cell death
2) They avoid the immune system
3) Induce angiogensis in tumour cells
4) Evading growth suppressors
5) Somatic mutation

Question 4

Define cancer as a genetic disease

Answer 4

Dominant genetic disease that is caused by genetic mutations that can be inherited by offsprings

Question 5

Define and give examples of tumour suppressor genes and oncogenes in cancer

Answer 5

Oncogene-a gene that is likely to cause cancer. It is a gene in it mutated form of a normal gene cell growth.
E.g Ras

Tumour suppressor genes-
A type of gene that regulates cell growth. When a tumour suppressor gene is mutated, uncontrolled cell growth may occur. This may contribute to the development of cancer.
E.g.p53

Question 6

Describe how mutations in Ras promote cancer

Answer 6

Ras normally controls growth,proliferation and migration.So when it becomes mutated it has an uncontrolled growth and proliferation.

Question 7

Describe how mutations in p53 promote cancer

Answer 7

P53 is normally activated by cell stress and it turns off cells that are stressed.And it cause apoptosis of damaged cell via binding to BAX.But when it becomes mutated it can cause cancer cells to grow spread in the body.

Question 8

Describe the basis and treatment of CML with reference to the underlying chromosomal abnormality characterised by BCR-ABL

Answer 8

CML is a type of cancer that affects the white blood cells and tends to progress over many years. In CML the bone marrow produces many myeloid cells-immature white blood cells that are not fully developed and do not work properly. This is caused by a mutation called translocation within the DNA known as a Philadelphia chromosome.
The treatment for CML include small molecular inhibitor -imatinib( tyrosine kinase inhibitor)

Question 9

Appreciate how genetic heterogeneity contributes to cancer progression and cellular heterogeneity

Answer 9

Genetic heterogeneity is when there is genetic diversity within tumours. The major cause genetic heterogeneity in a cancer genome is because genomic instability. This can lead to to an increased mutation rate and can affect the cancer pathway.

Question 10

Describe the two hit theory of inherited tumours

Answer 10

Non-hereditary cancer
This is when both parents are have healthy chromosomes. You eventually have two separate occurrence of mutation to DNA before getting cancer.

Hereditary cancer
This is one parent is a carrier and the other isn’t. This child only need one more mutation and it will develop into cancer because they were already born with the first mutation.

Question 11

Describe some of the screening approaches for diagnosing cancer

Answer 11

1) Screening for cancer will depend where symptoms are e.g. mammography for breast cancer and HPV testing cervical cancer. 2)However liquid tumour need a blood test.
3) Cytologic studies
4) Immunohistochemistry
5) Gene profiling techniques

Question 12

Describe in detail the pathogenesis of breast cancer

Answer 12

This is a malignant tumour that starts in the cells of the breast. A risk factor could be damage to the DNA, genetic mutations and could have inherited defects in the DNA like BRCA1,BRCA2 and P53.

Question 13

Describe some of the therapeutic approaches for the treatment of cancer including cell-cycle specific and non-specific chemotherapies

Answer 13

1) Surgery
2) Radiation therapy
3) Hormone therapy
4) Small molecule inhibitors
5) Chemotherapy
6) Immunotherapy

Question 14

Be able to describe the concept of immunotherapy

Answer 14

There are two types of immunotherapy;
Passive- this is when the patient is given a drug. These drugs have antibodies so they can fight off the cancer cells. E.g monoclonal antibodies

Active- this is when you are activating the immune system to eradicate cancer cells

Question 15

Describe how nivolumab is able to promote cancer regression through blockade of PD-1;PD-L1 interaction

Answer 15

Nivolumab blocks the activity of a molecule called PD1. PD1 is protein that prevents T cells from recognizing and attacking inflamed tissue and cancer cells. It does this by turning off the t cell when binds to PD-1 via the PD-L1 .It can trick your immune system into overlooking cancerous cells as normal cells.

Question 16

Appreciate the importance of monoclonal antibodies as an area of research for cancer.

Answer 16

Monoclonal antibodies are used to treat cancer. They are a type targeted cancer therapy so the specific to its targets.