Sporadic colorectal cancer Flashcards Preview

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Flashcards in Sporadic colorectal cancer Deck (8)
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1
Q

How does sporadic colorectal cancer arise?

A

Accumulation of acquired “driver” mutations

2
Q

Explain adenom-carcinoma sequence

A

Normal (APC mutation) early stage adenoma (KRAS mutation) larger adenoma (18q mutation SMAD2/4) larger adenoma (TP53 mutation) high grade, late stage adenoma

3
Q

In adenoma-carcinoma sequence why do mutations appear in a certain order?

A

Each mutation must have a selective advantage at that stage

4
Q

Testing performed for sporadic colorectal cancer

A

Sequencing of mutational hotspots in KRAS, NRAS, BRAF, PIK3CA (sanger or pyro)

5
Q

Treatment offered to individuals who are WT for all four genes tested

A

Anti-EGFR monoclonal antibody treatment (cetuximab)

6
Q

What is the EGFR pathway?

A

It is a signalling pathway that promotes cell division when a mutation is present

7
Q

Can you target EGFR if KRAS has a mutation?

A

No, can only target EGFR if downstream genes WT

8
Q

Explain Dukes colorectak cancer staging

A

A- invasion into but not through bowel wall
B-Invasion through bowel wall but not involving lymph nodes
C - involvement of lymph nodes
D - widespread metastases