Tumour Pathology 2

Question 1

What genes are lost in cancer cells?

Answer 1

Tumour suppressor genes such as adenomatous polyposis (APC), retinoblastoma (Rb) and BRCA1.

Question 2

What function is gained by cancer cells?

Answer 2

The gain of function of oncogenes such as
B-raf
Cyclin D1
ErbB2
Myc
K-ras and N-ras

Question 3

What are properties of cancer cells?

Answer 3

They have altered function and abnormal morphology.
The cells are capable of independent growth.
No single feature is unique to cancer cells which makes it difficult to treat.

Question 4

How does a cancer cell‘s function change?

Answer 4

There is loss of cell to cell and cell to matrix adhesion.

Tumour related proteins are produced.

Question 5

Name four tumour biomarkers

Answer 5

Onco-fetal proteins are expressed in foetal tissues then switched off but in cancers they’re switched on.
Oncogenes are switched on in cancers.
Growth factors and receptors are abundant in cancers.
Immune checkpoint inhibitors can be targeted by drugs.

Question 6

How can be tumour biomarkers be used clinically?

Answer 6

Screening (asymptomatic)
Diagnosis (symptomatic)
Prognostic (likely outcome)
Predictive (drug to use and response)

Question 7

Name four tumour biomarkers and what they can be used for in cancers

Answer 7

Alpha-fetoprotein is produced in teratoma of testes so is used to monitor therapies. It is used in hepatocellular carcinoma to diagnose it.
Carco-embryonic antigen is used to monitor patients with colorectal cancer.
Oestrogen receptor is in breast cancer and drugs can target these if it is positive for it.
Prostate specific antigen is used to diagnose prostate cancer and monitor therapy.

Question 8

What are predictive tumour biomarkers for different cancers?

Answer 8

Kras for colorectal cancer.
Braf for melanoma.
EGFR and PD-L1 for lung cancer.
Her2 for breast and gastric cancer.

Question 9

What is the morphology of cancer cells?

Answer 9

Cellular and nuclear pleomorphism which is marked Variation in size and shape.
Mitoses present and abnormal.

Question 10

Describe tumour angiogenesis

Answer 10

It is new blood vessel formation by tumours to sustain tumour growth. It also provides a release of tumour cells into circulation. More blood vessels in a tumour means a poorer prognosis.

Question 11

Describe tumour apoptosis

Answer 11

Mechanism of active programmed single cell death. It regulates tumour growth and is involved in chemotherapy and radiotherapy.

Question 12

What are some steps in invasion and metastasis?

Answer 12

Increased matrix degradation by proteolytic enzymes.

Altered cell to cell and cell to matrix adhesions.

Question 13

What are the main modes of spread of cancers?

Answer 13

Local spread (invading into adjacent structures)
Lymphatic spread
Blood spread
Trans-coelomic spread

Question 14

What is trans-coelomic spread?

Answer 14

It is a form of local spread but the tumour cells spread across body activities (pleural or peritoneal).
Tumours of lung, stomach, colon and ovary show trans-coelomic spread and it happens very rapidly.

Question 15

What are some common sites for metastasis?

Answer 15

Liver
Lung
Brain
Axial bone
Adrenal gland
Omentum (fatty lining in abdominal cavity)

Question 16

What are some uncommon sites of metastasis and what do they prove?

Answer 16

Spleen
Kidney
Skeletal muscle
Heart
They prove that metastasis is not solely related to blood flow as all structures receive lots of blood.

Question 17

Which different tumours metastasis to certain areas?

Answer 17

Breast and prostate tumours metastasise to the bone.
Colorectal tumours metastasise to the liver.
Ovary tumours metastasise to the omentum.