Cancer

Question 1

Why is difficult to find out which gene mutations in cancers cells result in cancer growth

Answer 1

The cell replication in cancers has made so many errors that is hard to see which one attributed to cancer growth because there are also many mutations that are not a cause just a consequence

Question 2

What is the difference in mutation between oncogenes and tumour suppressor genes

Answer 2

Mutation in one of the two chromosomes of a proto-oncogene can already lead to increased cell proliferation, while mutations in both copies of the tumour suppressor genes are required to prevent inhibition of cell cycle by products of these genes. The mutation in oncogene is therefore dominant and the mutation in tumour suppressor gene recessive.

Question 3

How does the process of micro-evolution in cancer work

Answer 3

The cancer cells that have a proliferative advantages over other cells outcompete the normal cells and when more mutations occur even more advantaged cancer cells might outcompetes first tumour cells and outcompetes normal cells for resources even more.

Question 4

What enzymes do malignant tumour cells secrete and what is its effect

Answer 4

Malignant tumour cells secrete proteases that break down the extracellular matrix and enable the tumour cells to migrate through tissue and grow through tissue architecture

Question 5

Which two processes are inhibited in cancer cells

Answer 5

The programmed cell death after to much DNA damage and cell cycle arrest to repair DNA are inhibited in cancer cells, causing rapid cell cycles and replication where the cell makes many mistakes in DNA replication that causes mutations

Question 6

What is the definition of a lesion

Answer 6

Region of the body that has suffered body due to injury or disease

Question 7

What is the definition of a tumour

Answer 7

Any lump forming lesion in the body

Question 8

What three causes can a tumour have

Answer 8

Tumour can be neoplastic, it can be hamartomatous and it can be inflammatory

Question 9

What is a hamartomatous lesion

Answer 9

A hamartomatous lesion is a local benign malformation of tissue architecture

Question 10

What is the definition of neoplasm

Answer 10

A tissue that has autonomous growth after escaping the constraints of cell proliferation

Question 11

In what two categories can neoplasms be divided and what do both types do

Answer 11

Benign, local neoplasm that remains situated in tissue and do not invade surrounding cells, and malignant, which invades cells of surrounding tissue and/or metastasises to different locations

Question 12

By which process do malignant neoplasms spread to other sites

Answer 12

Metastasis

Question 13

How can you palpate if a breast cancer is likely to be benign or malignant

Answer 13

If lump in breast is clearly demarcated and can be moved, it is a benign non-invasive tumour, but when it is fixed to the muscle or skin and is not clearly demarcated it is probably a malignant invasive tumour

Question 14

Which type of malignant cancers have a very low chance of metastasising

Answer 14

Skin cancers, melanomas

Question 15

Which type of benign tumours can prove to be fatal

Answer 15

Benign tumours in the brain can press against brain regions carrying out vital body function and so lead to death

Question 16

Are hamartomas architectural or cytological abnormalities

Answer 16

Hamartomas are architectural abnormalities, because the cell lack the dysplastic features that neoplasms do, they only form aberrant overgrowtg structures within tissues

Question 17

What is a heterotopia

Answer 17

A heterotopia is when a structure of normal tissue is found in an abnormal location of the body

Question 18

What are the primary and secondary descriptions of neoplasms

Answer 18

The primary description of a neoplasm depends on its cell origin, the secondary description determines if its a benign or malignant tumour

Question 19

What does the suffix “oma” mean in neoplasms and what does this distinguish

Answer 19

Suffix “oma” means that neoplasm is benign and so its distinguishes malignant and benign tumours

Question 20

What is transitional epithelium and where is it found

Answer 20

Transitional epithelium is also called uroepithelium and is epithelium that can change shape due to mechanical stress

Question 21

How would neoplasms in epithelial tissues in squamous, glandular and transitional epithelium be called

Answer 21

A benign squamous epithelium neoplasm would be squamous epithelioma, malignant squamous carcinoma, a benign glandular epithelium neoplasm adenoma, malignant adenocarcinoma, a benign transitional epithelium neoplasm transitional epithelioma, malignant transitional carcinoma

Question 22

How would neoplasms in connective tissue in smooth muscle and bone tissue be called

Answer 22

A benign smooth muscle neoplasm leiomyoma, malignant leiomyosarcoma, a benign bone neoplasm osteoma, malignant osteosarcoma

Question 23

What are haematologic benign neoplasms called

Answer 23

This is very uncommon

Question 24

What are teratomas, what do they consist of and where can they be found

Answer 24

Teratomas are tumours that consist of multiple cell types of three different germ cell layers, give rise to any tissue, both mature and immature, and are most commonly found in the ovaries and testicles

Question 25

Are teratomas benign or malignant neoplasms

Answer 25

Teratomas can be both benign and malignant neoplasms

Question 26

Which neoplasms with the suffix “oma” are always malignant

Answer 26

Lymphomas and melanomas are always malignant, hepatomas too but preferred name liver cell cancer

Question 27

What are the four differences between benign and malignant tumours

Answer 27

Benign neoplasms does not invade surrounding tissue while malignant neoplasms do, benign tumours do not metastasise while malignant neoplasms do, benign neoplasms are very similar in morphology (well differentiated) to surrounding tissue while malignant neoplasm cells can be very aberrant, benign neoplasms have very similar tissue architectural structure to surrounding normal tissue while malignant neoplasms can have very different tissue structure from original tissue

Question 28

What is carcinoma in situ

Answer 28

Most severe form of dysplasia before cancer, where very abnormal cells are found in tumour but do not invade surrounding tissues

Question 29

What distinguishes dysplasia or carcinoma in situ from cancer

Answer 29

Cancer cells invade surrounding tissues, where dysplastic cells and carcinomas in situ do not

Question 30

When does dysplasia turn into cancer

Answer 30

When dysplastic cells break through basement membrane of tissue and invade other tissues, it turns into cancer

Question 31

What is the difference in nuclear-cytoplasmic ratio between normal cells and tumour cells

Answer 31

Dysplastic and cancer cells have much larger nuclei and smaller cytoplasm as compared to normal cells

Question 32

What is the difference in mitosis between normal cells and tumour cells

Answer 32

Cancer cells may have abnormal mitosis, for instance tripolar mitosis, while normal cells have a bipolar mitosis

Question 33

What is nuclear pleomorphism

Answer 33

The variety in nuclear shapes and sizes

Question 34

How does the malignancy of a tumour relate to the architecture of the tissue

Answer 34

A malignant tumour resembles the tissue it originates from much less than a benign tumour does

Question 35

Why is the prognosis of a patient with metastasised cancer much worse than with local cancer

Answer 35

Because surgery to remove the tumour is virtually impossible if the tumour has spread to multiple organs, and also because metastasises can differentiate and mutate differently and not respond to chemotherapy in the same manner

Question 36

What are five routes by which cancers can spread

Answer 36

1. The direct extension, where cancers directly invade architecture of surrounding tissue, 2. haematogenous, where cancer cells enter the blood stream at site of initial tumour and metastasise to a distant location, 3. lymphatic, where cancer cells enter the lymphatic system at site of initial tumour and metastasise to a distant location, 4. transcoelomic, where cancer cells metastasise through body cavities that are easy to migrate through such as pleural and peritoneal cavities 5. perineural, where cancer cells proliferate in or along nerves through tissues

Question 37

What is iatrogenic spread of tumours

Answer 37

The spread of cancer cells through body through a medical procedure where cancer cells are by mistake dropped in surrounding tissues where they can proliferate

Question 38

What is the response of the body to direct extension spread of tumour called

Answer 38

The stromal response

Question 39

What are the three aspects of the stromal response to a tumour

Answer 39

The desmoplastic response, which produces collagen fibres around the tissue, angiogenesis, which increases formation of new vasculature around the tumour, and an immune response, which will try to destroy cancer cells

Question 40

What is the desmoplastic response in direct extension of tumours

Answer 40

In the desmoplastic response, fibroblasts will produce a network of collagen fibres that cancer cells can use as scaffolding mechanism to spread throughout a tissue

Question 41

Which blood vessels are often invaded in haematogenous spread of tumours

Answer 41

The capillaries and venules are often invaded, because those have thinner vessel walls and are hence easier to invade

Question 42

What is the difference in route of metastasis between sarcomas and carcinomas

Answer 42

Carcinomas often first spread via the lymphatic system, while sarcomas spread via the blood circulation

Question 43

What role does the location of a tumour play in preventing metastasis via lymphatic route

Answer 43

Where tumour is located determines which lymph node it will spread to first, so looking at draining lymph node to particular area of body can detect if metastases have taken place

Question 44

What is transcoelomic spread of cancer and what are the two most common examples

Answer 44

In transcoelomic spread of cancer, cells metastasise through body cavities that are easy to migrate through such as pleural and peritoneal cavities, because there is a lot of movement and it always moist which decreases resistance.

Question 45

What is the peritoneal cavity and how does this facilitate metastasis

Answer 45

The abdominal cavity that contains all abdominal organs. The organs in this cavity move a lot due to ventilation that causes changes in diaphragm and body movements that involve pressure to the abdomen. Additionally this is a very moist cavity which decreases resistance for metastasis.

Question 46

In which tumour is perineural route of metastasis often seen

Answer 46

Hepatic cancer

Question 47

What is TNM system and how does it assess stage of tumour spread

Answer 47

The system that assesses the severity and the stage of a cancer. It changes for every type of cancer and depends on the tumour size and invasion of local tissue, nodes invaded and presence of metastases

Question 48

What are the two most important features in assessing tumour prognosis and what is the most important of the two

Answer 48

Grade, how well differentiated tumour cells are and stage, how far and how much tumour has spread. Stage is more important, but the two are very related.