5. Diagnosis and treatment of colorectal cancer Flashcards
what is the survival rate for CRC?
53%
how many cases of CRC are preventable?
54%
why is prevention the best way to treat CRC?
over 50% of cases are driven by environmental factors that can be changed
how is the descriptive Epidemiology of CRC changing?
- CRC is reducing in older age groups but increasing in early onset cases
- age groups under 40 show higher rates of CRC
- CRC rates are not effected by gender
- younger people tend to have more advanced disease with lower survival after 5 years
- early onset CRC patients die from the cancer but late onset patients tend to die from other things so 5 year survival is not a good comparison
define the adenoma carcinoma sequence?
the multistep process leading to CRC
what is the adenoma carcinoma sequence?
- normal epithelium
- loss of APC and FAP
- Hyper proliferative epithelium
- DNA hypo methylation
- early adenoma
- K-Ras/BRAF mutation and inflammation
- intermediate adenoma
- loss of 18q/SMADs/CDC4
- late adenoma
- loss of 17q/TP53
- early carcinoma
- additional mutations
- late carcinoma
how long does adenocarcinoma take to develop?
around 10-15 years giving you time to detect it early
what determines how fast CRC will develop?
the type of mutations and the order it obtains them
what is the 2 week wait pathway?
a fast cancer diagnosis pathway
Political policy
have to be seen within 2 weeks
implemented because the UK have poor cancer outcome compared to the rest of Europe
the symptomatic diagnosis pathway
- large numbers of patients go to the gp with GI symptoms
- so use FIT test and persisting symptoms
- 10-30% of CRC patients present as an emergency
- develop a blockage/perforation
- if you reach this 2x more likely to be stage 3 or 4
what is the FIT test?
tests for human blood in the stool
invite to colonoscopy
for every 1200 people given this 1 will have CRC
why is the screening program good?
16% less at risk of dying when you have gone through the screening program
mostly picks up the early asymptomatic tumours which when removed prevent development of CRC
what is the polyp classification?
helps to determine which are at high risk of malignancy
haggit
kikuchi
paris
kudo
how many biopsies are taken from each tumour for diagnosis?
around 8 but they must be in the correct clinical context for diagnosis
ie important in metastatic disease to ensure CRC is the primary tumour
what kind of people are in a MDT?
- oncologist
- Pathologist
- radiologist
- nurses
- surgeon
- psychologist