PBL Block 9 Week 5

Question 1

HPV virus

Answer 1

Naked double-stranded DNA virus which replicates in the nucleus of the host cell and has an icosahedral shape

Question 2

How does HPV affect the cervix?

Answer 2

It infects the basal squamous cells of the cervix and replicates by hijacking the replication process of keratinocytes and as it ascends the epidermal junctions synthesises capsid proteins.

Question 3

Cervical cancer complications

Answer 3

Metasases to the inguinal lymph nodes and result in leg oedema. The tumour may compress onto the bladder or bowel and cause urinary problems. Fluid build up can occur around the kidney due to issue with urinary outflow and cause hydronephorosis.

Question 4

Cellular features of cancer

Answer 4

Scarce cytoplasm which reduces cell adhesion, prominent nucleoli due to fast rate of replication, large nucleus, poorly differentiated and irregular morphology. Increase in ribosomes and mRNA and mitochondria and poorly developed Golgi apparatus. More mitochondria but these are abnormal and results in abnormal glycolysis. Increase of smooth ER but this decreases along with rough ER

Question 5

How does cancer progress?

Answer 5

Hyperplasia: increase in size due to tissue growth
atypia: abnormal cell characteristics
metaplasia: change in one cell type to another
dysplasia: excessive non-neoplastic proliferation
Benign tumour
Malignant tumour

Question 6

What is cancer stage?

Answer 6

Extent of spread of tumour in the body

Question 7

What is cancer grade?

Answer 7

Level of differentiation.

Question 8

Cervical cancer symptoms

Answer 8

-> Abnormal heavy vaginal bleeding after sex that becomes more frequent and spontaneous
-> Red/brown vaginal discharge due to inflammatory response
-> Vaginal discomfort like irritation and pain
-> Dysuria: pain while urinating
-> Urinary retention

Question 9

Early cancer features

Answer 9

Night sweats, unexplained weight loss, unexplained bleeding, hyperplasia, appetite loss, breathlessness, prolonged healing, persistent pain.

Question 10

What are the UK cancer screening programmes?

Answer 10

Bowel cancer
Cervical cancer
Breast cancer

Question 11

What are the cancer cellular changes?

Answer 11

Scarce cytoplasm, prominent nucleoli due to fast rate of replication, large nucleus, poorly differentiated and irregular morphology.
Increase in ribosomes and mRNA and abnormal; mitochondria and poorly developed Golgi apparatus. Abnormal glycolysis. Increase of smooth ER but this decreases along with rough ER

Question 12

In situ melanoma

Answer 12

Hasn’t reached basement membrane

Question 13

Ex situ melanoma

Answer 13

Reached the basement membrane and can be invasive

Question 14

Eczema

Answer 14

Type 1 hypersensitivity reaction caused by deficiency in filaggrin protein present in the epidermis and junction abnormalities. This allows allergens to infiltrate the skin and induce Th1 immune response where Th2 are recruited. The dermis becomes damaged over time thickenings which causes lichenifications when there is excessive itching that leads to damage.

Question 15

Superficial spread melanoma

Answer 15

Present on the limbs of younger people due to intermittent high UV exposure.

Question 16

Lentigo melanoma

Answer 16

Melanoma restricted to the epidermis.

Question 17

What are the subtypes of cervical cancer?

Answer 17

Squamous carcinoma which is most common
Adenocarcinoma which has glandular characteristics

Question 18

What form of cervical cancer is inherited?

Answer 18

Squamous cell carcinoma which occurs in the ectocervix, which contains squamous epithelia

Question 19

What is an adenocarcinoma?

Answer 19

Malignant tumour in the mucous producing cells. In cervical cancer, this occurs in the endocervix, which contains glandular epithelia

Question 20

What is the epidemiology of cervical cancer?

Answer 20

Affects younger women aged 30-34, deprived areas, White women, low income countries, later stage diagnosis in Ethnic minorities

Question 21

Early cancer features

Answer 21

Night sweats due to inflammation as immune defence builds against tumour
Weight loss unexplained: this is a paraneoplastic syndrome called cachexia where the immune system is depleted of resources fighting the tumour, utilising protein stores in muscle tissue and fat oxidation. This can lead to fatigue
* Unexplained bleeding and bruising due to tumour angiogenesis or systemic effects of the tumour because of tissue damage eg, blood in urine, stools to metasases
* Lump or mass due to tumour hyperplasia
* A new mole or changes to existing moles
* Appetite loss
* Breathlessness and persistent cough
* Prolonged healing of injuries
* Persistent pain
* Change in bowel habits
* Difficulty swallowing
* Persistent bloating

Question 22

Melanoma risk factors

Answer 22

Type 1 skin that easily burns and freckles
High intermitted/long term UV exposure
Family history
Previous history of moles
Tanning beds
Genetics
Immunosuppression
Airline workers
Obesity

Question 23

Epidemiology of melanoma

Answer 23

Older white people, specifically men with fair skin, red hair and blue eyes. Australia has the highest incidence

Question 24

Types of tumour spread

Answer 24

Haematogenous spread, more prominent in veins than arteries due to thinner walls so metasases follows venous flow.
Lymphatic system is the most common route for carcinomas to spread throughout the body.
Transcolemic via the body cavities such as pleural, arachnoid, pericardial space which leads to organ compression and organ failure.

Question 25

What happens in metasasis?

Answer 25

It separates from the main tumour and infiltrates the basement membrane to enter the bloodstream, typically the veins and enter the lymphatic system to gain entry into the distant organs and result in the formation of new lesions and induce angiogenesis.

Question 26

Types of malignant tumours?

Answer 26

Carcinoma: due to altered epithelial cells, found on skin surface and internal organs
Sarcoma: change in muscle, bone, fat or connective tissue
Leukemia: malignant WBCS
Lymphoma: cancer of lymphatic system cells from bone marrow
Myeloma: Cancer of WBCS which produce antibodies

Question 27

Bacterial causes of skin infection

Answer 27

Staphylcoccal and streptococcal. and corynebacterium
Corynebacterium causes erythema

Question 28

How does squamous cell carcinoma present?

Answer 28

Scaly red patches, open red sores

Question 29

Lower limb malignant melanoma

Answer 29

Superficial spread

Question 29

Face malignant melanoma

Answer 29

Lentigo maligna melanoma

Question 29

Trunk malignant melanoma

Answer 29

Nodular

Question 30

What is CDK4?

Answer 30

Cell cycle and apoptosis mediator

Question 31

K-ras

Answer 31

Oncogene which causes adenoma formation in bowel cancer

Question 32

DCC

Answer 32

Colorectal cancer suppressor receptor when mutated leads to carcinoma

Question 33

What is the suicide enzyme?

Answer 33

DNA repair enzyme used in direct reversal, coded for by the human MGMT gene. Reduced expression of MGMT by cancer cells increases response to alkylating agents

Question 34

What is the most common category of mutation in cancer?

Answer 34

Somatic mutation due to compounds or spontaneous mutation

Question 35

Cause of FAP

Answer 35

Mutation of gatekeeper APC

Question 36

Cause of HNPCC

Answer 36

Mutation of caretaker MSH2 and MSL1

Question 37

Cell count for cancer death

Answer 37

10^12

Question 38

Cancer count for clinical detection

Answer 38

10^9 -> 10^12

Question 39

How does cancer drug resistance occur?

Answer 39

Subclones of the least resistance tumours are killed

Question 40

What is a subclone?

Answer 40

Clone from a founding clone which has an acquired mutation