Wk 1: Oncology nursing #1

Question 1

Define cancer

Answer 1

• a group of diseases characterised by any bodily cell acquiring the ability to divide and multiply in an uncontrolled way forming tumors and masses.

Question 2

What is significant about cancer cells?

Answer 2

They are derived from normal cells that have undergone a neoplastic transformation.

Can invade near by tissues

Question 2

Briefly outline the cell cycle

Answer 2

Gap 1-> post mitotic/pre synthesis phase
- growth

Synthesis
- DNA replication

Gap 2-> Post synthesis/Pre mitotic phase
- errors in replication are erased

Mitosis
- prophase
- metaphase
- anaphase
- telophase

Resting phase

Question 3

What are the two types of normal cell communication that must occur for correct cell function?

Answer 3

Indirectly: exchange of messenger compounds such as hormones or growth factors
Directly: cell to cell contact via cell adhesion molecules and to exchange messenger molecules though cell to cell portals called gap junctions- this allows them to feel what other cells are doing.

Question 4

Outline the initial process of cancer developing.

Answer 4

Cancer cells are normal cells in which the genetic code has a mix-up/abnormlaitities

This initiates the transformation of the normal cell by interrupted cell to cell communication; in turn upsetting the normal regulatory controls for cell division.

Once transformation occurs and an autonomous cancer cells is born, it divides to produce daughter cells which also divide exponentially, and soon there is a population of cancer cells characterized by uncontrolled growth and spread.

Question 5

Define doubling time and what does this mean for cencers?

Answer 5

Time taken for the tumour to double its volume

• the average time for most solid tumours being 2-3 months.
• Tumours are usually not clinically detectable until they have doubled around 30 times, equaling about 1 cm in size and around 1 gram in weight.

This may take years, depending on the type of cancer.

Death of the host usually occurs (due to excessive tumour burden) at around 40 doublings.

Question 6

Define growth fraction

Answer 6

the ratio of the total number of cells to the number of dividing cells.

As a rule, the higher the growth fraction, the more rapidly tumour mass increases.

Question 7

What is the gompertzian tumor growth curve?

Answer 7

= describes the decrease in cell doubling time as tumour progression occurs. This curve is also useful in describing tumour response to treatments.

Question 8

Describe the metastatic cascade.

Answer 8

1) Growth and progression of the primary tumour.

2) Cells detach from the primary tumour and motile cancer cells invade and enter the bloodstream or lymphatic vessels.

3) If they successfully evade the immune system, blood and lymph transport them to distant sites where the cells then extravasate and lodge in areas such as bones, lungs or liver,

4)Angiogenesis occurs and a blood supply to the new tumour site is established; feeding the tumour and resulting in further aggressive growth.

Question 9

What are some physical responses to getting a diagnosis

Answer 9

• Sleep disturbance
• Appetite changes
• Altered sexual interest
• Headaches
• Heart Palpitations
• Feeling ‘stressed’ and ‘on edge’
• Wanting to be around others/ social withdrawal
• Substance use / abuse

Question 10

What are the 5 domains of supportive psychological care

Answer 10

Physical
social
Psychological
Spiritual
Informational

Question 11

Describe cell differentiation and why this is significant for cancer

Answer 11

Differentiation: Normal cells acquire certain specialized characteristics of their tissue of origin.

Well differentiated= tumour cells reproduce these features well and look more like the normal cells of the tissues they began to grow in– ie.. Breast cells

Poorly differentiated – tumour cells reproduce these features poorly and are very different from the original cells they started growing in.– ie.. Difficult to tell the cell of origin
- agressive
- immature
- undeveloped

Question 12

Define Proto-oncogenes?

Answer 12

= are the normal genetic genes that help cells grow and develop normally.
- Promote health growth of cells
- Control the cell cycle
- Promote normal cell survival
- Tell us what needs to be killed of and what needs to be grown

Question 13

What is oncogenes

Answer 13

= genes that encourage changes to cells that are mutated form of proto-oncogenes

Question 14

Explain the progression from oncogenes to proto oncogenes

Answer 14

Proto-oncogenes become oncogenes when inappropriately activated by mutations in themselves or other genes normally controlling their function

Question 15

What is the P53 gene?

Answer 15

=a ‘gatekeeper’ gene that gets rid of mutations that may cause defective cells/cancer cells.
= encondes proteins that block the growth promoting proteins
- a turmor supressor gene
- known as the thoughest advanced defence mechanise

• Normally, p53 functions by halting the cell cycle in the G1 phase, allowing DNA repair genes to correct mistakes in DNA copying. If mistakes cannot be corrected, p53 induces apoptosis. When p53 is mutated, cells are able to replicate without repairing DNA damage, resulting in uncontrolled abnormal cell growth

*some cancers switch off P53 gene and thus enable the cancer to advance.

Question 16

Define neoplasm

Answer 16

an abnormal growth of tissue that can be benign (noncancerous) or malignant (cancerous).

Question 16

What is a tumor suppressor cell and what is the process?

Answer 16

= encondes proteins that block the growth promoting proteins
- When function lost, uncontrolled growth occurs Ie. when a mutation occurs in a tumour suppressor gene, the cell loses its ‘switch off,’ allowing cell growth to proceed unabated.

Question 17

Why are tumor cells continually proliferating despite this not being a normal cell function.

Answer 17

Because they fail to abide by normal cell restraints and due to their ‘loss of cellular surface contact inhibition’ or inability to proceed to the resting phase

Question 18

What is the metastic cascade

Answer 18

The metastatic cascade
- Tumour initiation
- Progression
- Proliferation (rapid growth and reproduction of new parts)
- Angiogenesis (formation of new blood vessel)
- Invasion / Intravasation
- Extravasation
- Colony Formation
- Evasion of host defenses

Question 19

What is a complete carcinogen?

Answer 19

just itself is a carcinogen e.g. cigarette smoke.

Question 20

What is the TNM staging system?

Answer 20

T (Tumour )
Size
Extent of Primary Tumour
E.g. (T1)

N (Nodes)
Number of nearby lymph nodes that contain cancer/cells
E.g. N3 (3 nodes)

M (Metastasis)
Spread to other sites and organs

Question 21

When staging a tumor, what is considered?

Answer 21

• Location of Tumour
• Type of Cells (such as germ cells or adenocarcinoma)
• Tumour Grade (how abnormal cells look compared to normal cells)
• Measurement of tumour size
• Lymph node spread of tumour cells
• Metastatic spread to other sites

Question 22

What are the current cancer screening and prevention running in australia?

Answer 22

1) breast screen

2) National bowel cancer screening program

3) cervical screening

Question 23

Explain key features of the breast screening program.

Answer 23

Women > 40 yrs.
Focus= 50-69 yr age group due to risk of breast cancer death for this age range.

Question 24

Explain key features of the National bowel screening program

Answer 24

• people aged 50-74 yrs receive a FOBT approximately every 5 years

Question 25

Explain key features of the cervical screening screening program

Answer 25

• Changes now suggest if HPV screening test is negative, pap testing can be delayed and testing completed less frequently.
• Direct result of HPV vaccination. If HPV positive, alternative screening suggested.
• Specific screening related to familial/genetic cancer risk.

-2 yearly

Question 26

What are the 5 phases of the cell cycle?

Answer 26

1. Gap 1
2. Synthesis
3. Gap 2
4. Mitosis
5. Resting

Question 27

What occurs in Gap 1 phase of the cell cycle?

Answer 27

Post mitotic/pre synthesis phase
- Growth phase
- Cytoplasm, mitochondria, proteins increases in side/numbers
- 18-13 hrs
- Time from end of mitosis to DNA synthesis
cells start to make enzymes for DNA synthesis and prepare for entry into the S phase

Question 28

What occurs in Synthesis phase of the cell cycle?

Answer 28

• Lasts 7 – 20 hours
• Proteins containing DNA are copied
• Synthesis of DNA leads to doubling of the total amount (DNA is replicated)
• Normal cell reproduction is dependant upon orderly synthesis of genetic material
• Cells are most vulnerable to damage during the S phase

Question 29

What occurs in Gap 2 phase of the cell cycle?

Answer 29

Post synthesis/Pre mitotic phase

• 2nd gap period.
• Lasts from 2 – 10 hours
• Errors in replication are corrected
• Specialised proteins and RNA are synthesised
• Cells are basically awaiting entry into the mitotic phase

Question 30

What occurs in Mitosis phase of the cell cycle?

Answer 30

• Stage of chromosomal duplication anc cell seperation
• Lasts 30 minutes to 2 hours
• Cell division occurs
• Duplication of the DNA MUST be complete before cells enter the mitotic phase

4 subphases :
Prophase *
Metaphase *
Anaphase *
Telophase *

Question 31

What occurs in go phase of the cell cycle?

Answer 31

Some cells do not enter the G1 pool, but enter the Go state, where they become temporarily or permanently quiescent/dormant.

• not active in the cell cycle
• Lasts from a few hours to a few years.
• Since at any given time, only 15-30% of cells are cycling, the Go cells are the largest population
• Some cells turn quiescent when they develop and form their function for the rest of the organisms life.