An introduction to Cancer (Pathology) Flashcards
How many people get some form of cancer?
1 in 3
What is the disease definition of cancer?
A group of diseases which share certain biological and pathological features
Define neoplasm
Abnormal mass of tissue, the growth of which exceeds and is uncoordinated with that of the normal tissues, and persists in the same excessive manner after cessation of the stimuli that evoked the change
What are the signs of breast cancer?
Nipple is indrawn
Swelling under the nipple
Hard lump (due to the connective tissue in the tumour)
What does an CRC look like?
It arises from the lining of the colon
Big lesion which oozes blood
What does advanced colon cancer look like?
The muscle coat is destroyed
There is white tissue which is the invading tissue
Doesn’t go into the lumen, invades into the wall
What does oestosarcoma of the femur cause?
Destruction of the hard cortical bone and this leads into the thigh muscle
Phenotype of melanoma
melanocytes darken and are ~1cm
Issue with liposarcoma
They can grow for years before they show a phenotype and it is very reoccuring
What is atrophy?
Cell loss > cell growth
How do tumour cells overcome the inability for oxygen to disease into the cell when they get to big?
When they undergo hypoxia they release stress signals and this causes the production of further vascular formation so that they are able to receive oxygen
What is the structure of a normal cell wall?
Mucosa at the top
Smooth muscle in the middle
A muscle coat at the bottom
How does stomach cancer metastasise?
There are glands which invade from the stomach outwards and drop into the paritoneal cavity
This commonly forms gastric or ovarian cancer
How are daughter cells of cancer different from their parents?
They have 3 identical spindles instead of 2 so they are unable to be identical to their parent
How can you distinguish mitotically active nuclei of cells on histology?
Their size and shape vary
What is an aneuploid population?
A group of cells who all have a different number of chromosomes
What chromosomes are associated with B-cell lymphoma?
Chromosome 11 is translocated onto chromosome 14
What is an adenoma?
Improper proliferation of the epithelial cells - they do not invade outwit the epithelial
What is dysplasia?
A preinvasive stage in a developing cancer
Process to develop an invasive tumour
Normal cell -> Initial event -> Early dysplasia -> Severe dysplasia -> Invasive malignancy
Phenotype of dysplasia
The nuclei are bigger
The cells are bigger in general
The cells are crowded
2 forms of single cell movement
Mesenchymal migration
Amboeboid movement
What is mesenchymal migration?
Proteolysis/ traction
What is amboeboid movement?
Propulsion/ utilise defects
How do groups of cells migrate?
- Require cell-cell adhesion and communication
- Predominates in well differentiated carcinomas
- Inner cells protected from immunological assault
- High levels of autocrine pro-migratory factors and of proteolytic enzymes
- Heterogeneous sets of cells invade together
Mechanisms cancer cells use to invade
Autocrine
Paracrine
Chemotactic factors
Proteolytic factors - degrade the connective tissue
Adhesion molecules - can pull themselves through
How can epigenetic factors effect cancer formation?
Histone modification and DNA methylation
Global hypomethylation
Tumour suppressors can be silenced by hypermethylation
What carcinogen can induce head and neck cancer?
Human papilloma virus
How does p53 regulate angiogenesis?
Represses VEGF and stimulates thrombospondin-1 expression
How doe ras and myc influence angiogenesis?
Stimulates VEGF production -> increase angiogensis
What is poor differentiation associated with?
A bad prognosis
What is the grading scale for differentiation?
1 - well differentiation
2 - moderately differentiated
3 - poor differentiation
How many doublings have to occur for a cancer to be clinically detectable?
30
How many doubling have to occur for the cancer to turn into an advanced cancer?
40
Where do primary CNS tumours spread to?
They stay within the CNS
What route do carcinomas favour to metastasise?
The lymphatic route
What route do sarcomas favour to metastasise?
haematogenous route
What therapy targets Her2 in breast cancer?
Trastuzumab
What is the issue with Her2 inhibitors?
Expensive
Only help a minority of patients
What cancers are associated with Epstein Barr virus (EBV)?
Lymphoma - usually high grade B cell
How do viral infections promote cancer?
- Stimulates increased proliferation
- Generates proteins which inhibit tumour suppressor function
- Integration into viral DNA
How do tumour cells evade the immune system?
Selection for less antigenic clones Reduce expression of MHCI Reduce expression of co-stimulatory molecules Immunosuppression Antigen masking Expression of FasL
How do tumour cells cause immunosuppression?
Oncogenic agents e.g. radiation and chemicals
Tumour products e.g. TGF-beta
Immune/ inflammatory responses e.g. IL-10 suppresses T cells
How does tumour cells cause antigen masking?
They produce mucopolysaccharides
How does FasL expression evade the immune system?
Will stimulate apoptosis in T cells which express Fas
