Colorectal Carcenoma - Copy.pptx..knowledge

for the under and postgraduate medical students

1. Colorectal Carcinoma Cadet Ye Htut Cadet Ye Sithu Aung Year 5 – Group B 22.7.2024

2. Contents Anatomy Epidemiology Aetiology Pathology Spread Staging Clinical features Investigations Management

3. Anatomy of Colon Length – 1.5m (5 feet) Parts – Caecum with appendix, ascending colon, hepatic flexure, transverse colon, splenic flexure, descend colon, sigmoid colon Characteristic features 3 taneniae coli Appendices apiploicae haustration

4. Blood supply Ileo -colic artery Right colic artery Middle colic artery Left colic artery Sigmoid artery Superior rectal artery Marginal artery of Drummond

5. Anatomy of Rectum Length – 12-18cm Start – S3 End – Coccyx (anorectal junction) Parts Upper third 4 cm Middle third 4cm (ampulla of rectum) Lower third 4 cm

6. Relations of the rectum Anterior Bladder Seminal vesicles and prostate (males) Denonvillier’s fasia (males) Pouch of Douglas and rectovaginal septum (females) Uterus and cervix (females) Ureters Lateral Lateral ligaments and middle rectal artery Obturator internus muscle and side wall of pelvis Pelvic autonomic plexus Levator ani muscle

7. Relations of the rectum Posterior Sacrum and coccyx Waldeyer’s fascial condensation Superior rectal artery and lymphatics Hypogastric nerves

8. Relations of the rectum

9. Blood supply Superior rectal artery Middle rectal artery Inferior rectal artery

10. What is colorectal cancer? Colorectal cancer starts in the colon or the rectum. Colon cancer and rectal cancer are often grouped together because they have many features in common. Cancer starts when cells in the body start to grow out of control.

11. Epidemiology Second most common causes of cancer death in UK One-third of diseases in rectum and two-thirds in colon Men : women = 3 : 1 Peak age of incidence 45-65 but is increasing in younger ages Occurs frequently in resource-poor world than in resource-rich countries

12. Aetiology Genectics APC (adenomatous polyposis coli) gene mutation(chromosome 5) – 60% of cases FAP (familial adenomatous polyposis) Autosomal dominant inherited disease due to mutation of APC gene >100 colonic adenomas are diagnostic Prophylactic surgery is indicated to prevent colorectal cancer Polyps and malignant tumours can develop in the duodenum and small bowel

13. FAP (Familial adenomatous polyps)- usually visible on sigmoidoscopy by the age of 15 years.

14. HNPCC (hereditary non-polyposis colorectal cancer) or Lynch’s syndrome Autosomal dominant Mutation in one of the DNA mismatch repair genes Increase risk of colorectal cancer and cancers of endometrium, ovary, stomach and small intestine Risk of cancer – 80% Mean age – 45 years Site – proximal colon Females – 30-50% risk of Ca endometrium

15. Aetiology Diets dietary fibres decrease risk dietary animal fat increases risk Life style Smoking alcohol drinking Predisposing conditions Inflammatory bowel diseases (UC and Crohn) Cholecystectomy Strong family history of colorectal cancer

16. Pathology Macroscopically Annular Tubular Ulcer Cauliflower Microscopically Columnar cell adenocarcinoma

17. Distribution of colorectal cancer by site Most large bowel cancers arise from the left colon

18. Spread Direct spread Ureter, duodenum and posterior abdominal wall muscles Adjacent organs or anterior abdominal wall Lymphatic spread Progress from closest to central nodes Blood-borne metastases Liver by portal vein, lung, ovary, brain, kidney and bone Transcoelomically spread From the serosa of bowel or subperitoneal lymphatics Peritoneum, ovary and omentum

19. Staging colon cancer Based on pathological reporting to predict prognosis and guide adjuvant treatment Two systems Dukes’ classification TNM system TNM system is regarded as the international standard.

20. Staging colon cancer Dukes’ staging for colorectal cancer A : invasion of but not breaching the muscularis propria B : breaching the muscularis propria but not involving the lymph nodes C : lymph node involved Dukes himself never describes a stage D, but this is often used to describe metastatic disease.

21. Dukes’ staging for colorectal cancer

22. Staging colon cancer TNM classification for colonic cancer T Tumour stage T1 Into submucosa T2 Into muscularis propria T3 Into pericolic fat or subserosa fat but not breaching serosa T4 Breach serosa or directly involving another organ N Nodal stage N0 No nodes involved N1 1-3 nodes involved N2 Four or more nodes involved M Metastases M0 No metastases M1 Metastases

23. TNM classification for colonic cancer

24. Clinical features Depends on site of the tumour Right sided (caecum and ascending) location Mass in RIF Iron deficiency anaemia Descending-sigmoid location PR bleeding – typically dark red, mixed with stool, sometime clotted Change in bowel habit – typically increase frequency, varieable consistency, mucus PR, bloating and flatulence Colicky abdominal pain Abdominal distension

25. Clinical features Transverse location Mass in epigastrium Iron deficiency anaemia Emergency presentations Occurs in 20% of cases Large bowel obstruction (colicky pain, bloating, bowel not open) Perforation with peritonitis Acute PR bleeding

26. Clinical features Features due to blood-borne metastases Liver – hepatomegaly and jaundice Lungs – cough, chest pain and haemoptysis Bone – bone pain Brain – fits and headache

27. Investigations Screening Faecal occult blood test (FOBT) Flexible sigmoidoscopy Colonoscopy Air contract barium enema (ACBE) CT colonography

28. Endoscopy Good for direct visualization of tumour Can take biopsy for histological assessment Two types of scope for lower GI Flexible sigmoidoscopy (60 cm long ) Colonoscopy (120-180 cm long ) - gold standard investigation highly sensitive and specific and can detect adenomas, polyps, synchronous tumours

29. Radiology Barium enema X ray useful for visualizing of right side of large bowel persistent irregular filling defect with apple core deformity biopsy is no possible and small lesions may be missed

30. CT scan virtual colonoscopy, which is extremely sensitive in picking up polyps down to a size of 6mm used as a diagnostic tool in patients with palpable abdominal masses CT of the chest, abdomen and pelvis represents the standard means of staging colorectal cancer biopsy cannot be taken PET scan Good for assessment of locoregional lymph nodes, primary tumour and distant metastasis

31. Ultrasound abdomen Shows metastasis in liver before and after surgery Detects tumour , ascites, lymph node enlargement and hydronephrosis MRI Requires additional staging for local spread

32. Laboratory For preoperative assessment Blood for complete picture BTCT, PT Sugar, electrolyte Urea and creatinine Liver function test ECG Grouping and matching

33. Management Potentially curative treatment suitable for technically resectable tumours with no evidence of metastasis Surgical resection (with lymphadenectomy) is the only curative treatment. Typical operations are Right and transverse – right or extended right hemicolectomy Left - left hemicolectomy Sigmoid – sigmoid colectomy Laparoscopic surgery Short-term benefits for patient recovery Reduced hospital stay, earlier return of bowel function Reduced morbidity in comparison with open surgery

34. Extended right hemicolectomy Left hemicolectomy

35. Sigmoid colectomy

36. Preoperative preparation Optimus fitness General condition of patient Respiratory and nutritional status If obstructed emergency, resuscitation, adequate rehydration, correction of electrolytes imbalance Counselling and consent Bowel preparation For 48 hours before surgery, liquid diet only and two sachets of picolax to purge the colon Rectal washout In emergency, on-table colonic lavage

37. Prophylactic antibiotics Immediately before the start of surgery Prophylactic lower molecular weight heprin For deep vein thrombosis prevention Neo-adjuvant therapy

38. Emergency surgery In the obstructed emergency cases , the primary relief of obstruction with a primary resection or colostomy is done In right sided , usually possible to perform a right hemicolectomy and anastomosis in the usual manner If perforation , bring out an ileocolostomy rather than forming an anastomosis In left sided , the decision lies between a Hartmann’s procedure or resection and anastomosis An expanding endoluminal metal stent can be treated Three stage procedure – primary decompression, resection of tumour at a later date and closure of colostomy

39. Postoperative care Hydration and monitoring of electrolytes Prophylactic antibiotics – cephalosporin and metronidazole Analgesia Catheterization Careful nursing and dressing wound Early enteral feeding DVT prophylaxis Care of colostomy

40. Palliative treatment For unresectable metastases or unresectable tumours , right sided - ileocolic bypass left sided - colostomy Radiotherapy Chemotherapy Hepatic Metastasis Can be resected and series have demonstrated 5 year survival of over 30% in resectable disease

41. Staging of rectal cancer Dukes’ staging A : The growth is limited to rectal wall (15%) B : The growth extends to extra rectal tissues, but without metastases to the regional lymph node (35%) C : Secondary deposit in the regional lymph node. C1 : Local para rectal lymph node alone are involved. C2 : The nodes accompanying the supplying blood vessels to their origin from the aorta are involved.

42. Staging of rectal cancer TNM staging – radiological staging T represents the extent of local spread TX : Primary tumour cannot be assessed. T0 : No evidence of primary tumour Tis : intraepithelial or invasion of the lamina propria T1 : tumour invades the submucosa T2 : tumour invades the muscularis propria T3 : tumour invades through the muscularis propria to the pericolorectal tissues T4a : tumour penetrates the surface of the visceral peritoneum T4b : tumour directly invades or is adherent to other organs or structures

43. N describes the nodal involvement NX : regional node cannot be assessed N0 : no regional lymph node metastases N1 : metastases in 1-3 regional lymph nodes N1a : in one regional lymph node N1b : in 2-3 regional lymph nodes N1c : tumour deposit in the subserosa , mesentery or pericolic or perirectal tissues without regional nodes metastases N2 : metastases in 4 or more regional lymph nodes N2a : in 4-6 regional lymph nodes N2b : in 7 or more regional lymph nodes

44. M indicates the presence of metastasis M0 : no distant metastasis M1 : distant metastasis M1a : metastasis confined to one organ or site M1b : metastasis in more than one organs

45. Clinical features Features due to primary tumour Bleeding per rectum – earliest and most common symptom Sense of incomplete defecation – important early symptom Alteration of bowel habit – increasing constipation and early morning bloody diarrhea Pain – late symptom Colicky pain : IO due to advanced carcinoma of rectosigmoid junction Severe pain in SPA : invasion of prostate or bladder Back pain or sciatica : invasion of sacral plexus

46. Features due to blood-borne metastases Liver – hepatomegaly and jaundice Lungs – cough, chest pain and hemoptysis Bone – bone pain Brain – fits and headache

47. On PR examination Early case – a nodule with an indurated base Ulcerated type – shallow depression with raised and everted edges Lower margin of tumour – distant from anal verge Examining finger – smeared with blood stained mucopurulent discharge On proctoscopic examination, good for Direct visualization of tumour Can take Punch biopsy ( Yeoman’s biopsy forcep ) For female, vaginal examination and bimanual examination done for anterior tumour

48. Investigations Endoscopy Rigid sigmoidoscopy Colonoscopy Radiology Barium enema X ray CT scan MRI for staging PET scan for distant metastasis

49. Laboratory For preoperative assessment Blood for complete picture BTCT, PT Sugar, electrolyte Urea and creatinine Liver function test ECG Grouping and matching

50. Management Curative procedure Surgical resection Palliative procedure Surgical by pass and stoma Radiotherapy chemotherapy

51. Surgery Surgery remains the mainstay of curative treatment for carcinoma of rectum Surgical management depends on the stage and location of the tumour within the rectum The general principles of a surgical approach remain the removal of all gross and microscopic disease with negative proximal, distal, and circumferential margins Reserve intestinal continuity and the sphinter mechanism whebever possible while still maximizing tumour control

52. Different surgical options For early cancers ; limited surgeries like Polypectomy Transanal excision Transanal endoscopic microsurgery (TEM) For advanced cancers Low anterior resection (LAR) or Abdominoperineal resection (APR)

53. Trans-anal excision Selected T1, N0 early stage cancers Small (<3cm) Well to moderately differentiated tumours Within 8cm of the anal verge Limited to less than 30% of the rectal circumference No evidence of nodal involvement

54. Abdominoperineal resection (APR) The gold standard for surgical resection of distal rectal cancer located within 6cm of the anal verge. This procedure requires a transabdominal as well as a transperineal approach with removal of the entire rectum and sphincter complex. A permanent end colostomy is created and the perineal wound either closed primarily or left to granulate in after closure of the musculature

55. Low anterior resection Sphincter saving operation Suitable for tumours of upper third, middle third and even some tumour of lower third Laparoscopic resection Short-term benefits for patient recovery Reduced hospital stay, earlier return of bowel function Reduced morbidity in comparison with open surgery

56. Other operations Hartmann’s operation Palliative colostomy Adjuvant therapy Only radiotherapy Radiotherapy + chemotherapy Other palliative procedures Self expanding metal stent (SEMS)

57. Prognosis

58. References Bailey and Love’s Short Practice of Surgery ( Norman S. Williams, Ronan O’Connel , Andrew W. McCaskie ).27 th Edition. 2018 Oxford Handbook of Clinical Surgery. 4 th Edition. 2013 Harold Ellis and Vishy Mahadevan’s Clinical Anatomy. 13 rd Edition. 2013 www.radiopaedia.com

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