Lecture 35: Characteristics of Tumours Flashcards
What is a tumour?
a swelling or mass of any kind
What is neoplasia?
New, uncontrolled growth of cells that is not under physiologic control.
Can be benign or malignant.
Define Cancer.
a generic term for a large group of diseases characterized by the growth of abnormal cells beyond their usual boundaries that can then invade adjoining parts of the body and/or spread to other organs
What are the 8 hallmarks of cancer?
- Sustaining proliferative signalling
- Evading growth suppressions
- Avoiding immune destruction
- Enabling replicative immortality
- Activating invasion and metastasis
- Inducing angiogenesis
- Resisting cell death
- Deregulating cellular energetics.
What 2 factors causes mutations to accumulate?
- Environmental factors causing mutations
- Inherited genetic mutations
What is embryological histogenesis?
The formation of differentiated tissues from undifferentiated
endoderm, ectoderm and mesoderm cells.
What is tumour histogenesis?
tumours are named according to the tissues from which they arise
Where does a carcinoma arise from?
Endoderm
Where do sarcomas arise from?
Mesoderm
Where do melanomas arise from?
Ectoderm
What is differentiation?
the extent to which aneoplasmresembles its tissue of origin
What is well-differentiated?
neoplasm closely resembles tissue of origin
What is moderately differentiated?
neoplasm shows some resemblance to tissue of origin
What is poorly differentiated?
neoplasm does not resembletissue of origin
What is anaplasia?
a neoplasm that is poorly
differentiated
AND highly
pleomorphic
What are the most common cancer in women in 2016 excluding non-melanoma skin cancers?
- Breast
- Lung
- Bowel
What were the 3 most common causes of death by cancer in women in 2017?
- Lung (21%)
- Breast (15%)
- Bowel (10%)
What are the most common cancers in men in 2016 excluding non-melanoma skin cancer?
- Prostate
- Lung
- Bowel
What were the 3 most common causes of death by cancer in male in 2017?
- Lung (21%)
- Prostate (14%)
- Bowel (10%)
What are the neoplasm characteristics
in terms of invasion if its benign?
Neoplasm does NOT invade surrounding tissues
What are the neoplasm characteristics in terms of invasion if it is malignant?
Neoplasm DOES invade surrounding tissues
Do benign tumour metastisise?
No
Do malignant tumours metastasise?
May metastasise
-Lymphatic
-Haematogenous
-Direct Seeding
What is the rate of growth of a benign tumour?
Slow rate of growth
What is the rate of growth in a malignant tumour?
Fast rate of growth (Division exceeds cell death)
Are benign tumour well differentiated?
Usually well differentiated
Are malignant tumours well differentiated?
A range of differentiation
Well Moderate Poorly differentiated anaplastic
What is usually the prognosis of benign tumours?
Rarely fatal (unless CNS)
What is usually the prognosis of a malignant tumour?
Often fatal
What are the three complications of tumours?
- Effects of primary tumours
- Effects of distant metastases
- Paraneoplastic syndromes
What are the primary effects of a tumour?
- Invasion into and replacement of normal tissues/ organs>failure of that organ to function (eg bone marrow, liver)
- Pressure on normal tissue - failure of that organ to function (esp in brain)
- Invasion into blood vessels>bleeding
- Pressure on blood vessels>ischaemia
- Pressure/ invasion into nervesàloss of nerve function / pain
- Grow into a lumenàobstruction (eg colon)
What are the effects of distant metastases?
When a cancer spreads to different parts of the body forming new (secondary) tumours
Invasion into tissues/ pressure on tissues/ Invasion into blood vessels etc
What are paraneoplastic Syndromes?
Signs and symptoms that are NOT related to local effects of the primary or metastatic tumours
What two factors causes the development of paraneoplastic syndromes?
- Proteins/ hormones secreted by tumour cells
- Immune cross reactivity between tumour cells and normal tissues
What is the stroma?
cells that support the
parenchyma
What is an organ?
parenchyma + stroma
What is the parenchyma?
cells that perform actual function of an organ eg cells that do gas exchange (pneumocytes)in the lungs, cells that contract in the heart (myocytes)
What are the main 3 cell types that the stroma contains?
-Blood vessels
2. Fibroblasts (And the collagen they make)
3. Immune cells
Is a tumour stroma similar to normal stroma?
Tumour stroma composed of the same cells types as normal stroma, but the stromal cells have different functions.
How is tumour stroma important?
Tumour stroma is required for a cell to acquire the ‘hallmarks of cancer’ and become malignant
