Colon cancer Flashcards
Treatment of Stage I (T1-2, N0, M0) colon cancer
Surgery then surveillance
Adjuvant therapy
- Start 6-8 weeks post operatively
- in high risk stage 2 or stage 3/4 (for micro-metastatic disease)
- FOLFOX (5FU with oxaliplatin) CAPOX (capecitabine + oxaliplatin)
- MOSAIC trial - better to add oxaliplatin
- IDEA trial - 3 months not inferior to 6m CAPOX (but not FOLFOX), high risk groups 6 months
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Microsatellite instablity (MSI-H)
No benefit of adjuvant chemo in stage II CRC
Implications of microsatellite stability in CRC
- Most colon cancers are microsatellite stable (MSS)
- MSI is measured best by checking for the 4 MMR genes:
- MLH 1, MSH2, MSH 6, PMS2
- A deficiency (dMMR) in 1 or more of these genes makes a tumour have microsatellite instability in it (i.e MSI-H = HIGH)
- MSI-H is seen in Lynch syndrome (HNPCC) but it is commonly seen in sporadic colon cancer as well due to MLH1 hypermethylation
- Having a MSI-H Stage II tumour confers LACK OF BENEFIT with adjuvant 5FU/capecitabine chemotherapy
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Treatment of Stage III CRC
- Standard adjuvant chemotherapy: 6 months of FOLFOX
- Single agent 5FU should not be used in stage II dMMR CRC
- Low risk stage III bowel cancer is 3 months of CAPOX, high risk patients 6 months oxaliplatin based chemo (SCOT trial and IDEA analysis)
FOLFOX (5FU with oxaliplatin)
CAPOX (capecitabine + oxaliplatin)
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Left or right sided CRC - which agent
Left - EGFR (osimetinib, gemfitinib)
Right - Bevacizumab (VEGF)
Colorectal Ca - screening guidelines
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Colonic polyps surveillance
![](https://s3.amazonaws.com/brainscape-prod/system/cm/323/193/191/a_image_thumb.jpg?1602045454)
CRC Screening
- general population
- high risk, inc what defines high risk
![](https://s3.amazonaws.com/brainscape-prod/system/cm/323/194/959/a_image_thumb.jpg?1602047334)
Treatment of Colon Cancer
![](https://s3.amazonaws.com/brainscape-prod/system/cm/323/208/459/a_image_thumb.jpg?1602065301)
Fluorouracil (5FU) Drug info
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Most common extracolonic manifestation of Lynch syndrome
Endometrial cancer!
Recommended Screening in Lynch Syndrome
![](https://s3.amazonaws.com/brainscape-prod/system/cm/323/208/807/a_image_thumb.jpg?1602065827)
Colorectal Cancer: Risk Factors
![](https://s3.amazonaws.com/brainscape-prod/system/cm/323/263/723/a_image_thumb.jpg?1602102459)
Management of Early Stage CRC
Adjuvant chemotherapy in stage II CRC - limited benefit
- Consider if high risk:
- T4 Primary tumour
- Perforation/obstruction
- lympho-vascular and perineural invasion
- poorly differentiated tumou
- inadequatelt sampled nodes (<12 LN)
- High pre op CEA?
- Single agent fluoropyrimidine (5FU or capecitabine)
![](https://s3.amazonaws.com/brainscape-prod/system/cm/323/264/856/a_image_thumb.jpg?1602102766)