Rectal cancer is defined as cancer within 12 cm of the anal verge. The document outlines the anatomy, history, examination, investigations, staging, and treatment guidelines for rectal cancer according to the NCCN. Treatment may involve local excision for early stage disease, or transabdominal resection with total mesorectal excision along with adjuvant chemotherapy depending on stage. Ablative techniques or resection may be considered for metastatic disease.

1. Rectal Adenocarcinoma
NCCN guidelines
Dr Ali Haider
Resident General Surgery
SU-2

2. NCCN defines rectal cancer as cancer located within 12 cm of the anal
verge by rigid proctoscopy.

3. Anatomy
• Length 12 cm to 15 cm
• 3 folds, namely the valves of Houston,
 Superior (at 10 cm to 12 cm)
 Inferior (at 4 cm to 7 cm)
[located on the left side]
 Middle fold (at 8 cm to 10 cm)
[located at the right side]

5. Introduction
• Colorectal cancer (CRC) is the fourth most frequently diagnosed
cancer.
• It is the second leading cause of cancer death in the United States

6. History
 Change in bowel habits (74%)
 Rectal bleeding (51%)
 Occult bleeding (26%)
 Rectal mass (24.5%)
 Abdominal mass (12.5%)
 Iron deficiency anemia (9.6%)
 Abdominal pain (3.8 %)

7. Examination
 Digital rectal examination (DRE)
• The average finger can reach approximately 8 cm above the dentate
line.
• Rectal tumors can be assessed for size, ulceration, and presence of
any pararectal lymph nodes.
• Fixation of the tumor to surrounding structures (eg, sphincters,
prostate, vagina, coccyx and sacrum) also can be assessed.
• DRE also permits a cursory evaluation of the patient's sphincter
function.

8. Cont.
 Rigid proctoscopy
• performed to identify the exact location of the tumor in relation to
the sphincter mechanism.

9. Investigations

10. Workup
 Rigid or flexible proctoscopy is recommended for all rectal tumors.
 Critical characteristics to be documented, in conjunction with digital rectal
examination, include
• tumor size,
• distances from the anal verge and the anorectal ring,
• orientationwithin the rectal lumen (eg, anterior-posterior, laterality) and/or
• degree of circumferential involvement,
• extent of obstruction,
• extent of fixation to the rectal wall,
• degree of sphincter involvement and
• sphincter tone.

11. Chest CT and abdominal CT or MRI
• Evaluate local extent of tumor or infiltration into surrounding
structures.
• Assess for distant metastatic disease to lungs, thoracic and
abdominal lymph nodes, liver, peritoneal cavity, and other
organs.
• If IV iodinated contrast material is contraindicated because
of significant contrast allergy, then MR examination of the
abdomen with IV gadolinium-based contrast agent (GBCA)
can be obtained instead.

12. Pelvic MRI with or without contrast or endorectal
ultrasound (only if MRI is contraindicated [eg,
pacemaker])
• Assess T and N stage of the primary rectal tumor.
• Pelvic MRI or CT can be used for workup of synchronous metastatic
disease.

13. Consider PET/CT (skull base to mid-thigh)
• If potentially surgically curable M1 disease in selected cases.
• In patients considered for image-guided liver-directed therapies for
liver metastases (ie, ablation, radioembolization).
• If liver-directed therapy or surgery is contemplated, a hepatic MRI
with intravenous routine extracellular or hepatobiliary GBCA is
preferred over CT to assess exact number and distribution of
metastatic foci for local treatment planning.

14. Staging of newly diagnosed rectal cancer

15. Screening for occult bleeding

16. Screening guidelines for colorectal syndromes

17. Dukes Staging
• Those limited to the rectal wall (Dukes A)
• Those that extend through the rectal wall into extra-rectal tissue
(Dukes B)
• Stage B was divided into B1 (tumor penetration into muscularis
propria) and B2 (tumor penetration through muscularis propria).
• Those with metastases to regional lymph nodes (Dukes C).
• Stage C was divided into C1 (tumor limited to the rectal wall with
nodal involvement) and C2 (tumor penetrating through the rectal wall
with nodal involvement).
• Stage D was added to indicate distant metastases

18. TNM Staging

19. Stage wise management
algorithms

20. Treatment for newly diagnosed cT1 rectal cancer

21. Treatment of newly diagnosed cT2N0 rectal adenocarcinoma or
cT1 disease not amenable to local excision

22. Treatment of newly diagnosed locally advanced rectal
adenocarcinoma (cT3-4Nx, TxN1-2)

23. According to NCCN guidelines

24. • If a pedunculated or sessile polyp is present with invasive cancer on
histopathology, transanal or transabdominal excision can be done as
follows,

25. For resectable lesion,

26. Management according to histopathology of transanal
excision

27. Management according to histopathology of transabdominal
excision

38. Local surgical techniques
The distal 10 cm of the rectum are accessible transanally.
Indication: Non circumferential, benign, villous adenomas, selected T1, and some T2, carcinomas.
Transanal endoscopic microsurgery (TEM) and transanal minimally invasive surgery (TAMIS)
Indications:
• Limit local excision of Ti lesions to patients with well to moderately differentiated small lesions
(<3 cm) and/or in patients medically unfit for radical resection.
• Should be considered excisional biopsy

39. Transanal Local Excision
Criteria
• <30% circumference of bowel; <3 cm in size; Margin clear (>3 mm);
• Mobile, nonfixed; Within 8 cm of anal verge; T1 only; Endoscopically
removed polyp with cancer or indeterminate pathology; No
lymphovascular invasion or PNI; Well to moderately differentiated; No
evidence of lymphadenopathy on pretreatment imaging; Full-thickness
excision must be feasible
• When the lesion can be adequately localized to the rectum, local excision
of more proximal lesions may be technically feasible using advanced
techniques, such as transanal endoscopic microsurgery (TEM) or transanal
minimally invasive surgery (TAMIS).

40. Limitations
• Local excision does not allow pathologic examination of the lymph
nodes and might therefore understage patients.
• Local recurrence rates are high after transanal excision, and salvage
surgery, while often curative, has been reported to be associated with
poorer survival than with initial radical surgery.

41. Ablative techniques
• Ablative techniques, such as electrocautery or endocavity radiation,
also have been used.
• The disadvantage of these techniques is that no pathologic specimen
is retrieved to confirm the tumor stage.
• Fulguration is generally reserved for extremely high-risk, symptomatic
patients with a limited life span who cannot tolerate more radical
surgery.

42. Transabdominal Resection:
• Abdominoperineal resection or low anterior resection or coloanal
anastomosis using total mesorectal excision (TME)

43. Lymph node dissection
• Clinically suspicious nodes beyond the field of resection should be
biopsied and/or removed, if possible.
• Extensive resection of M1 lymph nodes is not indicated.
• Extended lymph node resection is not indicated in the absence of
clinically suspected nodes.

44. Liver
• Hepatic resection is the treatment of choice for resectable liver metastases
from colorectal cancer.
• When hepatic metastatic disease is not optimally resectable based on
insufficient remnant liver volume, approaches using preoperative portal vein
embolization or staged liver resections can be considered. Ablative techniques
may be considered alone or in conjunction with resection
• All original sites of disease need to be amenable to ablation or resection,
arterially directed catheter therapy, and in particular yttrium-90, microsphere
selective internal radiation, Ablative external beam radiation therapy (EBRT)

45. Lung
• Complete resection based on the anatomic location and extent of
disease with maintenance of adequate function is required.15-18
• Ablative techniques may be considered alone or in conjunction with
resection for resectable disease. All original sites of disease need to
be amenable to ablation or resection.
• Ablative techniques can also be considered when unresectable and
amenable to complete ablation.
• Ablative EBRT may be considered in highly selected cases

46. Adjuvant therapy
mFOLFOX
• Oxaliplatin, leucovorin
• Repeat every 2 weeks to a total of 6 month perioperative therapy.
CAPEOX
• Oxaliplatin, Capecitabine
• Repeat every 3 weeks to a total of 6 months perioperative therapy.
FOLFIRINOX
• Oxaliplatin, leucovorin, irinotecan, fluorouracil.
• Repeat every 2 weeks.
Modified FOLFIRINOX
• Oxaliplatin, leucovorin, irinotecan, fluorouracil.
• Repeat every 2 weeks.