Colorectal Cancer Flashcards
Risk factors for CRC? (10)
Always Categorise.
Demographics: Age, diet (red-meats), Smoking, Alcohol
Comorbidities: IBD, Diabetes, Obesity, ImmSx, RTx (to abdo/pelvis), Urinary diversion (e.g. ileal conduit)
Endoscopic: previous polyps - how many, how large
FH of CRC/ familial syndromes
Colorectal cancer - PRIC MCP?
P: from surveillance, constitutional symptoms, PR bleed, obstruction, abdo pain, change in bowel habit, symptomatic anaemia. Stage?
R: risk factors for CRC (demographic, FH, comorbidities)
I: latest colonoscopy, PET scan. If pre-op, work-up for operation (e.g. TTE/PFT)
C: complications of the disease (perforation, anaemia/collapse/GI haemorrhage) or of therapies (chemo, MABs, RTx)
M: current Tx, previous Tx (chemo, imm, surg, RTx)
C: latest disease/functional status, freq of F/U, plan for next-line of therapy, how is patient/family affected / work
P: insight into prognosis, complications of therapies, ACD
Surveillance guidelines based on the index colonoscopy?
No polyps or small hyperplastic polyps (<1cm) - 10 years
1-2 small TAs (<1cm): 5-10y
3-10 small polyps (<1cm): 3y
1 or more with ≥1cm: 3y
>10: 1-2y
What is the screening strategy for average, moderate, or high risk of CRC?
- Average = FOBT from 50 (consider q5y flexi-sig?)
- Moderate = FOBT from 40; Colonoscopy q5y from 50 (or 10y younger than 1st dx CRC in family)
- High = FOBT from 35; Colonoscopy q5y from 45
What constitutes a moderate risk of CRC? (FH)
- 1 FDR with CRC <55 or
- ≥2 relatives (1st or 2nd) at any age
What constitutes high risk of CRC? (4)
- ≥3 FDR or SDR with at least one dx <55
- ≥3 FDR at any age
- ≥1 relative with endometrial or ovarian cancer (HNPCC)
- Suspected or documented FAP in the family
Patient with FAP - 4 additional questions to ask?
- Soft tissue or bony tumours? (Gardiner’s syndrome)
- Tumours in CNS (Turkot’s syndrome)
- Both are variants of FAP.
- Whether they are on surveillance Gastroscopy for duodenal/periampullary cancers every 1-3 years (from age 25)
- Whether offsprings are screened (DNA testing for APC gene mutation)?
What is Lynch syndrome?
AD disorder caused by germline mutation in MMR genes (MLH1, MSH2, MSH6, PMS2)
The most common inherited CRC susceptibility syndrome (3% of newly diagnosed CRC)
Associated with other extra-colonic tumours - especially endometrial Ca.
When should you suspect HNPCC (Lynch syndrome) for further evaluation? (5)
The current guidelines - Amsterdam or Bethesda are limited in identifying individuals at risk → suspect when:
- Synchronous or Metachronous CRC
- CRC <50y
- Multiple Lynch syndrome-associated cancers
- Family clustering of Lynch-associated cancers
- Fulfills criteria in guidelines - e.g. 3-2-1 rule of Amsterdam (3 affected members, 2 generations, 1 <50y)
What is the recommended criteria for colonoscopic surveillance in HNPCC (Lynch) patient? (1)
Annual colonoscopy from age 20-25, or 10y before 1st cancer in the family.
What are Lynch-associated cancers? (3 broad)
GU: Endometrial, Ovary, Renal tract (pelvis/ureter)
GI: entire GI tract (Gastric, HPB, SB, CRC)
Brain (glioma)
Peutz-Jeghers syndrome? (3) surveillance strategy? (1)
Haematomas of the GIT
Mucocutaneous pigmentation
Increased risk of cancers of colon, SB and gyneocological Cas (breast, uterine, ovarian)
Surveillance endoscopy 3 yearly from 18y of age.
Amsterdam II criteria for HNPCC?
3-2-1 rule
3 affected members of HNPCC associated cancers
2 generations or more
1 or more CRC before age of 50.
Start screening at 25yo
Why is it important to identify those with MSI instability tumours?
Better prognosis and response to chemo
What is the initial screening test for patient suspected of having HNPCC?
Testing for presence of MSI in a tumour or adenoma
Positive test should undergo genetic screening
