Big 4 and oncological emergencies Flashcards
Most common colorectal cancer type?
How common in CR cancer and who is affected?
Pathophysiology?
Adenocarcinoma
4th most common cancer: 2nd most common cause of UK deaths. Mainly affects adult >60. M:F equally affected. M
Originates from the epithelial cells in the colon or rectum.
Most colorectal cancers develop via a progression of normal mucosa to colonic mucosa to invasive adenocarcinoma- this is the adenoma-carcinoma sequence
Spread of CRC
Risk factors for CRC?
Spread occurs via lymphatic, blood (liver, lung, bone) or transcoelomic
Neoplastic polyps
IBD (Crohn’s or UC)
Genetic predisposition e.g. FAP and HNPCC (Dominant condition which gives you a higher risk of colon and other cancers)
Peutz-jeghers syndrome: Pigmented spots on lips and buccal mucosa. Small intestinal polyps may bleed obstruct or cause intussusception
- Main predisposing genes are:
- Adenomatous polyposis colic (APC): A tumour suppressor gene, mutation of the APC gene results in growth of adenomatous tissue- this is associated with FAP (familial adenomatous polyposis)
- HNPCC: A DNA mismatch repair gene, mutation to HNPCC leads to effects in DNA repair- associated with Lynch syndrome
Diet: Low fibre or high consumption of red and processed meats
Alcohol
Smoking
Previous cancer
Inactivity
Polyps are removed to prevent later development to cancer
Where are most tumours located in CRC?
Symptoms/ red flags
Left side of the colon
Alteration in bowel habit Colicky abdo pain Rectal bleeding/ Melaena Change in bowel habit Vague abdominal pain Mucous PR Anorexia/Weight loss Abdo or rectal mass
Signs of CRC?
Abdominal mass Perforation Haemorrhage Fistula Anaemia: systemic sign of cancer Left side: Bleeding/mucus PR, altered bowel habit, obstruction, tenesmus, mass PR Right side: Decreased weight
Investigations for CRC?
FBC: To assess for macrocytic anaemia (unusually large red blood cells)
LFT
FIT
Colonoscopy: Gold standard: suspicious lesions are biopsied/ tattooed for surgery
Sigmoidoscopy: Endoscopy of the rectum and sigmoid colon only
CT colonography: bowel prepped with contrast but less detailed and can’t take biopsy
If family history of FAP refer for DNA test once >15
Carcinogenic Antigen: CEA: should not be used for diagnosis but should be used to monitor progression
CT CAP/TAP, will show evidence of metastasis or mass if present
MRI rectum: definitive imaging test for rectal cancer, will demonstrate soft tissue more appropriately. Will show vascular invasion n(V1-V5), enlarged lymph node or tumour extension out of the bowel wall
Test for RAS and BRAF V600E mutations in all people with metastatic colorectal cancer suitable for systemic anti-cancer treatment
Medical treatment for CRC?
- Mostly used in palliation for colonic cancer
- Consider pre-op SACT (neo-adjuvant) for people with CT4
- Stage III: CAPOX regimen FOR 3 months (capecitabine +oxaliplatin) or if not suitable, Folfox regimen: Fluorouracil, folinic acid and oxaliplatin. If not suitable
- Single agent fluoropyrimidine for 6 months
- Bevacizumab (Anti-VEGF antibody) improves survival when added to combination therapy
- Cetuximab and Panitumumab- anti-EGFR agents improve survival in Kras wild type metastatic colorectal cancer
Surgical options for CRC?
- Right hemicolectomy for caecal ascending or proximal transverse tumours
- Left hemicolectomy for tumours in distal transverse or descending colon
- Sigmoid colectomy for sigmoid tumours
- Abdomino-perineal resection for tumours low in the rectum: removes anus and rectum: sutures over the anus leaving a permanent colostomy
- Endoscopic stenting: should be considered for palliation in malignant obstruction
- Harman’s surgery: complete resection of the recto-sigmoid colon with the formation of an end colostomy and the closure of the rectal stamp. Emergency procedure often used for acute obstruction of a tumour/ significant diverticular disease
What staging system is used for CRC? What are the stages?
Complications of surgical treatment for CRC?
Duke’s Staging:
- Dukes A: Limited to muscularis mucosae
- Dukes B: Extension through muscular mucosae
- Dukes C: Involvement of regional lymph nodes
- Dukes D: Distant metastasis
- Bleeding, infection and pain
- Damage to nerves, bladder, ureter or bowel
- Post-operative ileus
- Anaesthetic risks
- Leakage or failure of procedure
What’s the 2ww criteria for colorectal Ca?
For referral: Nice recommends:
- > 40 years with unexplained weight loss and abdo pain
- > 50 years with unexplained rectal bleeding
- > 60 years with iron deficiency anaemia or change in bowel habit
- Positive occult blood test screening
- Age <50 w/ rectal bleeding and 1 of: abdo pain, bowel change, weight loss and irondef anaemia
- Sole IDA without any other explanation is an indication for a 2 week wait referral for colonoscopy and gastroscopy
Occult blood screening-
- Age >50 with unexplained abdo pain or weight loss
- Age <60 with bowel change or Fe def anaemia
What’s the follow up for patients who have had CRC?
For local recurrence and distant metastasis for the first 3 years- follow up should include serum carcinoembryonic antigen (CEA) and CT chest abdo pelvis for the first 3 years
Monitor for lower anterior resection syndrome to people who will potentially have sphincter preserving surgery; symptoms include: increased frequency of stool, urgency with or without incontinence, incomplete emptying, fragmentation of stool and difficulty in differentiating between gas and stool
What test should be conducted prior to starting patients on 5FU?
DPD testing: dihydropyrimidine dehydrogenase
All patients receiving 5FU chemotherapy tested for DPD enzyme deficiency- heterozygous: this results in an inability to metabolise 5FU: severe toxicity and patients have a severe reaction
How common is prostate cancer and who is mainly affected?
80% men >80 years old
Lifetime incidence of 1 in 8 men
Affects black men at the highest incidence
Pathophysiology of prostate cancer:
Genes responsible, pattern of spread, location of most prostate cancers?
What type of cancer is prostate cancer?
Genes include BRCA1 and BRCA2, mismatch repair and HOXB13
Spread may be local (seminal vesicles, bladder and rectum), lymph or haematogenously- sclerotic bony lesions
Most adenocarcinomas arise in the peripheral prostate (95%)
It’s an Androgen dependent cancer
RFs for prostate cancer?
Increasing age (esp >50)
Black ethnicity (afro-caribbean) = 1 in 4 lifetime incidence
Positive FamHx: 1st degree, increases risk by 2.5 times
FamHx of other heritable cancers e.g. breast/ colorectal
High levels of dietary fat
BPH, BRCA2, PTEN gene: tumour suppressor gene
Prostate Ca symptoms ?
Nocturia Terminal Dribbling Haematuria Hesitancy Obstruction Poor Stream Frequency Haematospermia Lower back pain/ bone pain: due to mets
