Colorectal cancer

1. Rectal Cancer

2. Anatomy of Colon

3. Risk Factors for Colorectal Cancer
• Average risk: Hamartomatous polyposis
syndromes; Age 50 years and older; Peutz-Jeghers
syndrome; Asymptomatic Juvenile polyposis
• Increased risk: Family history; Inflammatory bowel
disease; Colorectal cancer; Chronic ulcerative
colitis; Colorectal adenomas; Crohn disease, long-
standing; Hereditary nonpolyposis colorectal cancer;
Familial adenomatous polyposys (including Gardner
and Turcot syndromes); Personal history; Breast,
ovarian, or uterine cancers

4. Anatomic Areas of Large Intestine and
Correlating Colorectal Symptoms
• Right colon: Microcytic anemia; Occult blood in
stool; Palpable mass in right lower quadrant
• Left colon: Hematochezia; Obstructive
symptoms; Small-caliber (pencil-size) stools;
Cramps; vague abdominal pain; Change in
bowel habits
• Rectum: Rectal bleeding; Change in bowel
habits; Pain; Change in stool caliber;
Tenesmus

5. THE LARGE INTESTINE
• Symptoms such as altered bowel habit, rectal bleeding, abdominal pain, weight loss
and anemia may indicate serious colonic disease. Colonoscopy and barium studies
are complementary and equally useful but their deployment depends to a large
extent on the availability of colonoscopy services. Many clinicians use the barium
enema as the first-line diagnostic investigation and either combine this with flexible
fibreoptic sigmoidoscopy or reserve a full colonoscopy for those instances where a
barium study is inconclusive or where a lesion shown radio-logically requires
further direct examination and biopsy.
• Barium studies require full bowel preparation using one of a variety of cleansing
techniques (fecal residue may mimic polyps or tumors). A double-contrast
technique involves inflation of the colon using air or carbon dioxide, and peristaltic
activity is temporarily abolished using a short-acting atropine-like pharmacological
agent.
• Colonoscopv provides direct access to lesion- or suspicious areas of mucosa for
biopsy: small polypoid lesions may be amenable to removal during the same
diagnostic procedure. The examination may not be complete because in a
significant proportion (10-30%) the caecum is not reached and there are also
‘blind’ spots at points of angulations of the colon. Advanced diverticular disease
produces deformity and narrowing that is difficult to assess both in barium studies
and during colonoscopy.
• Colonoscopy has a significantly higher risk of complications than barium enema,
and the procedure is more time consuming.

6. Common disorders of the large
intestine
• Carcinoma: Most are irregular strictures with ‘shouldering’. Destroyed
mucosal pattern, proximal dilatation and obstruction. Invasion of adjoining
tissues and organs. May appear as polyp, usually more than 2 cm with
complex surface pattern. Long-standing ulcerative colitis and familial
polyposis coli are predisposing conditions.
• Diverticular disease: Multiple diverticula particularly in sigmoid region,
but may be widespread. Narrowing and deformity. Common, so may
coexist with cancer. May bleed or perforate, or form fistulae, e.g. with
bladder.
• Ulcerative colitis: Diffuse, uniform fine ulceration; loss of haustra, giving
featureless tubular colon. Toxic megacolon and carcinoma are
complications. May only involve distal colon or rectum in some cases.
• Crohn’s disease: Areas of narrowing, deep ulceration, strictures. Perianal
disease is common. Prone to form fistulae. Coexists with small bowel
disease often.
• Ischaemic colitis: Cause of profuse bleeding and acute abdominal pain.
Narrowing of lumen, often affecting localised segment, with mucosal
edema (‘thumb-printing’). Occasionally difficult to distinguish from
Crohn’s disease

7. CRC: Diagnostic Workup Procedures
• Staging workup procedures:
Colonoscopy and/or double-contrast barium enema
(used to identify synchronous carcinomas and
adenomas); Chest-radiograph; CT scan (in
staging rectal cancer, it is helpful to evaluate local
spread to adjacent organs, pelvic bones, or liver);
MRI (for staging rectal cancer); Endoluminal
ultrasonography (useful for finding local spread into
rectal wall and occasionally for detecting perirectal
nodes); Biopsy of lesion; Cystoscopy (for low
sigmoid or rectal lesions); HIV testing (anal cancers
are associated with acquired immunodeficiency
disease syndrome)

8. CRC: Diagnostic Workup Procedures
• Laboratory studies:
CBC with differential and platelet count
Liver enzymes (SGOT, SGPT, alkaline
dehydrogenase, and lactate
dehydrogenase)
Electrolytes
PT and PTT
BUN and creatinine
CEA

9. TNM Clinical Classification
T - Primary tumor
T0 No evidence of primary tumor
Tis Carcinoma in situ
T1 Tumor invades submucosa
T2 Tumor invades muscularis propria
T3 Tumor invades through muscularis propria into subserosa or into non-
peritonealized pericolic or perirectal tissues
T4 Tumor directly invades other organs or structures and/or perforates
visceral peritoneum
N - Regional lymph nodes
N0 No regional lymph node metastases
N1 Metastasis in 1-3 regional lymph node
N2 Metastasis in 4 or more regional lymph node
M - Distant metastasis
M0 No distant metastasis
M1 Distant metastasis

10. Stage grouping
Stage 0 TisN0M0
Stage I T1-2 N0M0 Dukes A
Stage IIA T3N0M0 Dukes B
Stage IIB T4N0M0 (surv. 50-65%)
Stage III A T1-2N1M0 Dukes C
Stage III B T3-4N1M0 (15-40%)
Stage III C any T N2M0
Stage IV Any T Nx-2 M1 Dukes D
(< 5%)

11. Colonoscopy: polyps

12. Endoscopic polypectomy

13. Rectal Cancer: lymphatic ways

14. Patient’s position for surgery on rectum

15. Surgery of Rectal Cancer: Step 1

16. Surgery of Rectal Cancer: Step 2

17. Surgery of Rectal Cancer: Step 3

18. Scheme of abdomino-perineal resection of
rectum (Quenu-Miles operation)

19. Colostomy

20. Anterior resection of rectum

21. Anterior resection of rectum

22. End-to-end stapled anastomosis

23. Scheme of abdomino-perianal resection with
coloanal anastomosis

24. Coloanal anastomosis

25. Posttreatment Monitoring and Surveillance For
rectal Cancer
Interim history and physical examination including DRE every 3
mo for 2 yr, then every 6 mo to 5 yr;
CBC + chemistries every 3 mo for 2 yr, then every 6 mo to 5 yr;
If CEA elevated at diagnosis or within 1 wk of colectomy, repeat
CEA every 6 mo for 2 yr, then annually for 5 yr;
Chest radiograph every 12 mo to 5 yr of treatment if stage B2
or C, or every 6 mo to 5 yr of treatment if liver or abdominal
metastases resected, or every 3 mo to 5 yr of treatment if
lung metastases resected;
Abdominal CT every 6 mo to 5 yr, then annually for 3 yr if liver
or abdominal metastases resected, or every 6 mo to 5 yr,
then annually for 3 yr if rectal tumor resected;
Chest CT every 6 mo to 5 yr if lung metastases resected;
Colonoscopy in 1 yr if negative for multiple synchronous polyps;
repeat in 1 yr if negative, then repeat every 3 yr.