Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Y2 - CANCER > Cancer as a Disease – Colorectal Cancer > Flashcards

Cancer as a Disease – Colorectal Cancer Flashcards

1
Q

What type of carcinoma are most colon cancers?

A
  • Adenocarcinoma
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is a polyp?

A
  • Any projection from a mucosal surface into a hollow viscus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is an adenoma?

A
  • Benign neoplasm of the mucosal epithelial cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the different types of colonic polyp?

A
  • Metaplastic/hyperplastic
  • Adenoma
  • Juvenile
  • Peutz-Jegher
  • Lipomas
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

State some characteristics of hyperplastic polyps

A
  • These are VERY COMMON 90% of all colonic polyps
  • They have NO malignant potential
  • 15% have K-ras mutations
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the different types of colonic adenoma?

A
  • Tubular
  • Tubulovillous
  • Villous
  • NOTE: the more villous it is the worse it is
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the different shapes of colonic adenomas?

A
  • Pedunculated – looks like a tree
  • Sessile – looks like a hedge
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the difference between tubular and villous adenomas?

A
  • Tubular– COLUMNAR cells with nuclear enlargement, elongation, multi-layering and loss of polarity + increased proliferative activity + reduced differentiation
  • Villous– MUCINOUS cells with nuclear enlargement, elongation, multi-layering and loss of polarity. May be exophytic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Describe dysplasia, and what are the 3 stages of dysplasia?

A
  • Abnormal growth of cells with some features of cancer for example……
  • Disorganisation including pseudostratification where unexpected, hyperchromatic nuclei with a high nuclear : cytoplasmic ratio
  1. Indefinite
  2. Low grade
  3. High grade
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the most famous condition that causes an increased number of colonic polyps?

A
  • Familial Adenomatous Polyposis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What gene mutation is FAP caused by?

A
  • Mutation in 5q21 - APC mutation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What do adenomas often progress into?

A
  • Often progress into carcinomas
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the two genetic pathways in colorectal cancer?

A
  1. Adenoma-carcinoma sequence = presence of adenomas will increase the risk of colorectal cancer
  2. Microsatellite instability
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are microsatellites?

A
  • Repeat sequences of DNA that are prone to misalignment
  • Some microsatellites are found in coding sequences of genes which inhibit growth or are involved in apoptosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Describe adenoma-carcinoma progression

A
  • Dysplastic cells in adenoma
  • There is accumulation of damage to the DNA leading to loss of control of proliferation
  • The cells become invasive as well
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

State two genetic diseases that predispose to colorectal cancer

A
  • Familial adenomatous polyposis – inactivation of the APC tumour suppressor gene
  • Hereditary Nonpolyposis Colorectal Cancer (HNPCC or Lynch syndrome) – microsatellite instability (affects mismatch repair genes)
17
Q

State some dietary factors that can increase the risk of colorectal cancer - i.e. things that are bad in the diet - not in regards deficiencies

A
  • High fat
  • Low fibre
  • High red meat
  • Refined carbohydrates
18
Q

State two dietary deficiencies that can increase the risk of colorectal cancer and how they increase the risk

A
  1. Folates– important for nucleotide synthesis and DNA methylation
  2. MTHFR
  • Deficiency leads to disruption of DNA synthesis and DNA instability (this leads to mutation)
  • It also causes decreased methionine synthesis leading to genomic hypomethylation and focal hypermethylation – this can have gene activating and silencing effects
19
Q

Give 4 anti-cancer elements in food and how they work to have anti-cancer benefits

A
  1. Vitamin C: ROS scavenger - scavenges free radicals that would otherwise damage DNA
  2. Vitamin E: ROS scavenger - scavenges free radicals that would otherwise damage DNA
  3. Isothiocyanates (found in cruciferous vegetables)
  4. Polyphenols (green tea, fruit juice) - activate MAPK
20
Q

What is the clinical presentation of colorectal cancer?

A
  • Change in bowel habit
  • PR bleeding
  • Unexplained iron deficiency anaemia
21
Q

Describe the distribution of colorectal cancer

A
  • RECTOSIGMOID –55%
  • Caecum/Ascending –22%
  • Transverse –11%
  • Descending –6%
22
Q

What are the 3 subtypes of adenocarcinoma in colorectal cancer?

A
  1. Mucinous carcinoma
  2. Signet ring cell
  3. Neuroendocrine
23
Q

Describe the Dukes classification of colorectal cancers

A

DUKES A

  • Growth is limited to the wall (muscularis propria)
  • Nodes negative

DUKES B

  • Growth beyond the muscularis propria
  • Nodes negative

DUKES C1

  • Nodes positive
  • Apical nodes negative

DUKES C2

  • Apical nodes positive
24
Q

State some clinical features that affect the prognosis of colorectal cancer

A
  • Bowel obstruction (diminished prognosis)
  • Age < 30 (diminished prognosis)
  • Distant metastases (diminished prognosis)
25
Q

State some pathological features that affect the prognosis of colorectal cancer

A
  • Depth of bowel wall penetration
  • Number of regional lymph nodes involved
  • Venous invasion
  • Lymphatic invasion
26
Q

What are the criteria for a screening programme?

A
  • Condition should be important with respect to the seriousness and/or frequency
  • The natural history of the disease must be known in order to:
  • Identify where screening can take place
  • To enable the effects of any intervention to be assessed
27
Q

What are the characteristics of a screening test?

A
  • Simple and acceptable to the patient
  • Sensitive and selective
  • Cost effective
  • Screening population should have equal access to the screening procedure
28
Q

What does the NHS colorectal cancer screening look for?

A
  • Faecal occult blood (FOB)
  • If positive and 55-60 years = sigmoidoscopy
  • If positive and over 60 years = full colonoscopy

Y2 - CANCER (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions