Cancer

What is cancer?

aberrant uncontrolled/unregulated growth of cells

What are tumour suppressor proteins (TSP)?

proteins which normally function to restrict (stop/slow) cell growth

What are the classes of tumour suppressor proteins?

• caretakers

• gatekeepers

What are caretaker tumour suppressor proteins?

DNA repair proteins that control the maintenance of the genetic information integrity

What are gatekeeper tumour suppressor proteins?

proteins that control the speed of cell division (cell cycle regulators)

What are examples of caretaker tumour suppressor proteins?

ATM, BRCA, PARP1

What are examples of gatekeeper tumour suppressor proteins?

p53, APC, PTEN

What type of cell is most susceptible to cancer?

differentiated cells (though can theoretically occur in any cell)

What is benign growth?

a growth that is confined to a specific site within tissue (encapsulated, localised), gives no evidence of invading adjacent tissue

What is malignant growth?

a growth that shows evidence of being locally invasive and possible metastatic, consists of poorly differentiated cells that grow and divide rapidly

What are the main forms of cancer?

• carcinoma

• sarcoma

• leukaemia

• lymphoma

What is carcinoma?

a form of cancer that originates from epithelial cells found at internal and external linings

What is adenocarcinoma?

a type of carcinoma that develops from simple epithelial cells of an organ or gland (e.g. breast, lung, liver, colon, prostate, endometrium)

What is adenoma?

benign form of adenocarcinoma

What is squamous cell carcinoma?

a type of carcinoma that develops from squamous epithelial cells of organs (e.g skin, oesophagus, oral)

What is a papilloma?

a benign form of squamous cell carcinoma

What is sarcoma?

a form of cancer that originates from connective tissue cells (non-epithelial cells)

What is a fibroma?

a benign tumour that originates from fibroblasts

What is fibrosarcoma?

a type of sarcoma that develops from fibroblasts

What is lipoma?

a benign tumour that originates from fat cells

What is liposarcoma?

a type of sarcoma that develops from fat cells

What is osteoma?

a benign tumour that originates from bone cells

What is osteosarcoma?

a type of sarcoma that develops from bone cells

What is leiomyoma?

a benign tumour that originates from smooth muscle cells

What is leiomyosarcoma?

a type of sarcoma that develops from smooth muscle cells

What is leukaemia?

cancer of the blood that originates from cells of the bone marrow (leukocytes)

What are the different types of leukaemia?

• acute myeloid (granulocytes/monocytes) leukaemia

• chronic myeloid (granulocytes/monocytes) leukaemia

• acute lymphoid (lymphocytes) leukaemia

• chronic lymphoid (lymphocytes) leukaemia

What is lymphoma?

cancer of the lymphatic system that originates from lymphocytes not from bone marrow (forming solid tumours)

What are the main hallmarks of cancer?

1) sustained proliferative signalling

2) evading growth suppressors

3) resisting cells death

4) enabling replicative immortality

5) inducing angiogenesis

6) activating invasion and metastasis

7) reprogramming cellular metabolism

8) evading immune destruction

What are the stages in the progression of a carcinoma?

1) healthy cells

2) hyperplasia (over-replication of cells)

3) dysplasia (cells look abnormal)

4) carcinoma in situ (cells are cancerous but contained)

5) invasive carcinoma

What are somatic mutations?

mutations only found in tumour cells that originate in non-germ line cells and cannot be inherited

What are germline mutations?

mutations present in gremlin cell (egg, sperm), which can make the individual pre-disposed to cancer and can be inherited

What are the different cancer evolution theories?

• clonal theory

• genetic predisposition theory

• host predisposition theory

What are the different approaches to treating cancer?

• surgery

• radiotherapy

• chemotherapy

• targeted therapy (small molecule inhibitors, antibodies)

• immunotherapy