Rectal cancer is the second most common cause of cancer death after lung cancer. It occurs most often in those over 50 years old. Adenocarcinoma makes up 98% of rectal cancers. Diagnostic workup includes physical exam, proctoscopy, colonoscopy, MRI or CT scan to determine tumor stage. Treatment depends on stage but may include surgery such as transanal resection or total mesorectal excision, with the goal of removing the tumor and lymph nodes. Chemotherapy and radiation therapy are also often used. Prognosis depends on stage, with 5-year survival rates over 90% for early stage but less than 3% for metastatic disease.

1. Rectal Cancer
Dr. Sultan Zahir

2. Rectal Cancer
 Rectal cancer is a disease in which cancer cells form in
the tissues of the rectum; colorectal cancer occurs in the
colon or rectum. Adenocarcinomas comprise the vast
majority (98%) of colon and rectal cancers; more rare
rectal cancers include lymphoma (1.3%), carcinoid
(0.4%), and sarcoma (0.3%).
 Second most common cancer death after lung cancer.
 Lifetime risk
 1 in 10 for men
 1 in 14 for women
 Generally affect patients > 50 years (>90% of cases)

3. WHO Classification of Rectal Carcinoma
 Adenocarcinoma in situ / severe dysplasia
 Adenocarcinoma
 Mucinous (colloid) adenocarcinoma (>50%
mucinous)
 Signet ring cell carcinoma (>50% signet ring cells)
 Squamous cell (epidermoid) carcinoma
 Adenosquamous carcinoma
 Small-cell (oat cell) carcinoma
 Medullary carcinoma
 Undifferentiated Carcinoma

4. Clinical Presentation
 Bleeding is the most common symptom of rectal cancer,
occurring in 60% of patients. However, many rectal cancers
produce no symptoms and are discovered during digital or
proctoscopic screening examinations.
Other signs and symptoms of rectal cancer may include the
following:
 Change in bowel habits (43%): Often in the form of diarrhea;
the caliber of the stool may change; there may be a feeling of
incomplete evacuation and tenesmus
 Occult bleeding (26%): Detected via a fecal occult blood test
(FOBT)
 Abdominal pain (20%): May be colicky and accompanied by
bloating

5.  Back pain: Usually a late sign caused by a tumor invading or
compressing nerve trunks
 Urinary symptoms: May occur if a tumor invades or
compresses the bladder or prostate
 Malaise (9%)
 Pelvic pain (5%): Late symptom, usually indicating nerve
trunk involvement
 Emergencies such as peritonitis from perforation (3%) or
jaundice, which may occur with liver metastases (< 1%)
 ( Rectal metastasis travel along portal drainage to liver via
superior rectal vein as well as systemic drainage to lung via
middle inferior rectal veins.)

6. Examination
Signs of primary cancer
 Abdominal tenderness and distension – large bowel
obstruction
 Intra-abdominal mass
Digital rectal examination – most are in the lowest 12cm and
reached by examining finger
 Rigid sigmoidoscope
Signs of metastasis and complications
 Signs of anaemia
 Hepatomegaly (mets)
 Monophonic wheeze
 Bone pain

7. Clinical Staging
TNM Primary Lymph-node Distant Dukes
stage tumor metastasis metastasis stage
Stage 0 Tis N0 M0 A A
Stage I T1 N0 M0 A A1
T2 N0 M0 A B1
Stage II T3 N0 M0 B B2
T4 N0 M0 B B2
Stage III
A any T N1 M0 C C1/C2
B any T N2, N3 M0 C C1/C2
Stage IV any T any N M1 D D
Astler-Coller
modified
Dukes stage

8. Dukes classification-
Dukes A: Invasion into but not through the bowel wall.
Dukes B: Invasion through the bowel wall but not involving
lymph nodes.
Dukes C: Involvement of lymph nodes
Dukes D: Widespread metastases
Modified astler coller classification-
Stage A : Limited to mucosa.
Stage B1 : Extending into muscularis propria but not
penetrating through it; nodes not involved.
Stage B2 : Penetrating through muscularis propria; nodes not
involved
Stage C1 : Extending into muscularis propria but not
penetrating through it. Nodes involved
Stage C2 : Penetrating through muscularis propria. Nodes
involved
Stage D: Distant metastatic spread

9. Tis T1 T2 T3 T4
Extension
to an adjacent
organ
Mucosa
Muscularis mucosae
Submucosa
Muscularis propria
Subserosa
Serosa
TNM Classification

10. Stage and Prognosis
Stage 5-year Survival (%)
0,1 Tis,T1;No;Mo > 90
I T2;No;Mo 80-85
II T3-4;No;Mo 70-75
III T2;N1-3;Mo 70-75
III T3;N1-3;Mo 50-65
III T4;N1-2;Mo 25-45
IV M1 <3

11. Diagnostic Workup
 History—including family history of colorectal cancer or
polyps
 Physical examinations including DRE and complete
pelvic examination in women: size, location, ulceration,
mobile vs. tethered vs. fixed, distance from anal verge
and sphincter functions.
 Proctoscopy—including assessment of mobility,
minimum diameter of the lumen, and distance from the
anal verge
 Biopsy of the primary tumor

12. Colonoscopy or barium enema
Figure: Carcinoma of the rectum. Double-
contrast barium enema shows a long
segment of concentric luminal narrowing
(arrows) along the rectum with minimal
irregularity of the mucosal surface.
To evaluate remainder of large bowel to rule out synchronous
tumor or presence of polyp syndrome.

13. Transrectal ultrasound –EUS
 use for clinical staging.
 80-95% accurate in tumor staging
 70-75% accurate in mesorectal
lymph node staging
 Very good at demonstrating layers of
rectal wall
 Use is limited to lesion < 14 cm from
anus, not applicable for upper
rectum, for stenosing tumor
 Very useful in determining
extension of disease into anal canal
(clinical important for planning
sphincter preserving surgery)
Figure. Endorectal
ultrasound of a T3 tumor of
the rectum, extension
through the muscularis
propria, and into perirectal
fat.

14. CT scan
 Part of routine workup of patients
 Useful in identifying enlarged pelvic lymph-nodes
and metastasis outside the pelvis than the extent or
stage of primary tumor
 Limited utility in small primary cancer
 Sensitivity 50-80%
 Specificity 30-80%
 Ability to detect pelvic and para-aortic lymph nodes
is higher than peri-rectal lymph nodes.

15. Figure: Mucinous adenocarcinoma of the
rectum. CT scan shows a large
heterogeneous mass (M) with areas of
cystic components. Note marked luminal
narrowing of the rectum (arrow).
Figure: Rectal cancer with uterine
invasion. CT scan shows a large
heterogeneous rectal mass (M) with
compression and direct invasion into the
posterior wall of the uterus (U).

16. Magnetic Resonance Imaging (MRI)
 Greater accuracy in defining extent of rectal cancer
extension and also location & stage of tumor
 Also helpful in lateral extension of disease, critical in
predicting circumferential margin for surgical excision.
 Different approaches (body coils, endorectal MRI &
phased array technique)
 Mercury study:
 711 patients from 11 European centers.
 Extramural tumor depth by MR & histo-pathological evaluation
equivalent.

17. Figure: Mucinous adenocarcinoma of
the rectum. T2-weighted MRI shows high
signal intensity (arrowheads) of the
cancer lesion in right anterolateral side
of the rectal wall.
Figure: Normal rectal and perirectal
anatomy on high-resolution T2-weighted
MRI. Rectal mucosa (M), submucosa
(SM), and muscularis propria (PM) are
well discriminated. Mesorectal fascia
appears as a thin, low-signal-intensity
structure (arrowheads) and fuses with the
remnant of urogenital septum making
Denonvilliers fascia (arrows).

18. PET with FDG
 Shows promise as the most sensitive study
for the detection of metastatic disease in
the liver and elsewhere.
 Sensitivity of 97% and specificity of 76% in
evaluating for recurrent colorectal cancer.
cancer
rectum
prostate pubic bone
bladder
Small bowel

19.  CEA: High CEA levels associated with poorer survival
 Routine investigation
 Complete blood count, KFT, LFT
 Chest X-ray

20. Treatment
Surgery Chemotherapy Radiotherapy

21. Surgical Options
 Trans-anal resection
 Anterior resection/CAA
 Abdomino-perineal

22. ■ Local excision
• Transanal
• Total mesorectal excision
■ Direct contact radiotherapy
■ Electrocautery
Local Treatment (Low Rectal Cancer)

23. ■ Tumor < 8 cm from anal verge
■ Tumor size < 3 cm ( < 1/3 circumference)
■ Histology; well or moderately differentiated
■ UT1 or UT2 with or without radiotherapy
■ Absence of lymph nodes
■ Nonulcerated tumors
■ Mobile
Ideal Criteria for Curative Local Treatment of
Rectal Cancers

24. ■ Full thickness disc excision
■ 2 cm margin
■ Full thickness stay sutures
■ Use electrocautery
■ Closure of incision may implant or bury microscopic tumor
Transanal Excision of Rectal Cancer

25. Transanal excision
 For T1 or T2 tumors
 Somewhat controversial
 due to higher local
 recurrence rates
 Only routinely used in older
 patients or those with
 co-morbidity

26. Surgical principles
 High vascular ligation
(Corder, Br J Surg, 1992)
 Remove lymph node basin
(Total Mesorectal Excision)
 “En bloc” resection if necessary

27. Total Mesorectal Excision

28. Total mesorectal excision
 Standardized technique
 4 to 9% local recurrence rate
 Heald, Lancet 1986
 Lavery, Surgery 1997
 Heald, Arch Surg 1998
 Dutch Trial suggests benefit with
XRT

29. Abdomino-perineal resection

30. Anterior resection
 Cancer of the rectum
 Join colon to low rectum
 Permanent colostomy
if tumor too low

31. Colorectal Anastomosis
 Suture by hand
 Staple with instrument
 Sometimes protect with temporary
ostomy

32. Colonic J-pouch
 Proposed by Parc and
Lazorthes 1986
 6cm vs 12 cm pouch
 Increases reservoir
 Improves short term
function, reduces leak rate

33. Coloplasty
Fazio et al, DCR 2000

34. Concerns regarding Laparoscpic
Surgery
 Learning curve
 Reduced ability to define distant disease
 Difficulty localizing lesion
 Adequacy of resection
 OR time and costs
 Port implantation of tumor