Colorectal Cancer

1
Colorectal Cancer
By GILUR RAHMAN
2
Introduction

• Second most common cause of cancer deaths in the
  UK.
• Each year 30,000 new cases diagnosed (68 colon,
  32 rectal)
• Disease more common in westernised countries then
  Asia or Africa

3
Aetiology

• Age (56 gt70yrs old)
• Colorectal polyps
• Family history
• Genetic
• Hereditary non-polyposis colorectal cancer
  (HNPCC)
• Familial adenomatous polyposis (FAP)
• Previous colorectal cancer
• Ulcerative colitis /colonic crohns disease
• Diet hit fat/low fibre
• Smoking
• Alcohol drinking
• Lack of exercise

FAP- http//cancerquest.org/images/CancerByType/pi
cs/colon_fap.jpg
4
Pathology/Pathogenesis

• Adenoma-carcinoma sequence
• Synchronous tumours found in 2 of cases
• Most of the tumours found on the left side of the
  colon
• Spread is through local invasion through the bowl
  wall and via local lymphatics, blood (portal vein
  into liver) and transcoelomic.
• Histology shows well differentiated glandular
  epithelium with mucin production. Signet rings
  common characteristics

5
Symptoms

• Left sided tumour
• Tenesmus
• Blood in stool (fresh red blood)
• Obstructive symptoms
• Change in bowl habit
• Colicky abdominal pain
• Nausea vomiting
• Right sided tumour
• Weight loss
• Anaemia
• Abdominal mass (late stage)

6
Investigations

• Rectal examination
• Bloods tests
• - FBC (can show anaemia)
• - CEA (carcino embryonic antigen tumour marker
  normally used to monitor treatment)
• - LFTs (show liver secondaries)
• - faecal occult blood
• proctoscopy
• Barium enema
• Sigmoidoscopy tumours in the last 15cm of GI
  tract
• Colonoscopy can take biopsys
• Ultrasound/CT used to stage look for metastasis
  (liver)
• CT colonography less invasive then colonoscopies

7
Staging

• Dukes
• Type A tumour confined to mucosa/sub mucose
• Type B invaded through bowl wall but lymph
  nodes clear
• Type C regional lymph nodes involved
• Type D - Distant metastasis

8
TNM Staging System (Tumor, Node, Metastisis)

• Tumor
• T1 Tumor invades submucosa. T2 Tumor invades
  muscularis propria. T3 Tumor invades through
  the muscularis propria into the subserosa, or
  into the pericolic or perirectal tissues. T4
  Tumor directly invades other organs or
  structures, and/or perforates.
• Node
• N0 No regional lymph node metastasis. N1
  Metastasis in 1 to 3 regional lymph nodes. N2
  Metastasis in 4 or more regional lymph nodes.
• Metastasis
• M0 No distant metastasis. M1 Distant
  metastasis present.

9
Stage Groupings

• Using the TNM criteria colorectal cancers are
  placed in to 4 stages
• Stage I T1 N0 M0 T2 N0 M0
• Stage II T3 N0 M0 T4 N0 M0
• Stage III any T, N1-2, M0
• Stage IV any T, any N, M1

http//homepage.ntlworld.com/watson-jones/portfoli
o/illustration-08.html
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Management

• Surgery
• Right colon tumours right hemicolectomy
• Transverse colon tumours extended right
  hemicolectomy
• Descending colon tumours left hemicolectomy
• Sigmoid tumours - Sigmoid colectomy

11

• Right rectal tumour anterior resection (tumour
  removed colon anastomosed with remaining rectum)
• Low rectal tumour - Abdomioperoneal resection
  excise rectum and anus leaving patient with a
  permanent colostomy

12

• The idea is to remove entire section of bowl
  supplied by same blood vessel as tumour to ensure
  clearance of all cancer cells.
• Adjuvant chemotherapy increases survival in Dukes
  B and C.
• Neo-adjuvant radiotherapy can be used for rectal
  tumours, difficult to use with colonic tumours
  due to the colon not being fixed in a certain
  position.
• Total mesorectal excision (TME) inproves prognosis

13
Prognosis

• Depends upon stage of the cancer
• Over 95 survival in dukes A tumours that have
  been resected
• When cancer has spread to lymph nodes far from
  the colon or rectum, to the lining of the
  abdominal cavity, or to other organs, the cancer
  cannot be cured by surgery alone. Survival time
  is typically only about 7 months