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
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
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