Rectal Carcinoma

1. Rectal Carcinoma
Pranjal Rokaya
Resident General Surgery
KIST MCTH
Moderator
Assoc. Prof. Dr. Deepak
18th January, 2023

2. Outline
• Introduction
• Epidemiology
• Risk factors
• Pathogenesis
• Clinical presentation
• Investigations
• Pretreatment staging
• AJCC classification
• Neoadjuvant therapy
• Surgical treatment
• Adjuvant therapy
• Post-treatment surveillance
• Prognosis

3. Introduction
• Carcinoma: Tumor arising from the epithelial cells.
• The majority of rectal cancers are adenocarcinoma.

4. Anatomy of rectum
Rectum and relation to anal canal

5. Arterial and venous distribution Lymphatic drainage

6. Colorectal cancer: Epidemiology
• 2nd most common malignancy globally; affecting more than a million people
every year.
• 150,000 new cases of large bowel cancer diagnosed annually in USA.
• 1/3rd of them arise from rectum.
• Mortality rate of 1.2% per year.
• 3rd most common cause of cancer deaths in the USA.

7. Risk factors
• Age
• Hereditary syndromes
• IBD
• Abdominopelvic radiation
• Renal transplantation
• Diabetes mellitus
• Red and processed meat
• Smoking and alcohol
Protective factors
a. Physical activity
b. Diet high in fruits and vegetables
c. High fibre diet
d. Folic acid, Vitamin B6
e. Coffee intake; garlic
f. NSAIDS and Aspirin

8. Pathogenesis

9. Types of Carcinoma spread
a. Local spread : Circumferentially rather than longitudinally.
b. Lymphatic spread : Mostly in an upward direction
c. Venous spread : Liver (34%), Lungs (22%)

10. Clinical presentation
1. Suspicious signs and symptoms.
2. Asymptomatic individuals are discovered by routine screening.
3. Emergency admission with intestinal obstruction, perforation, or rarely acute
GI bleed.

11. Symptoms from local tumor
Right sided tumor Left sided tumor
a. Iron deficiency anemia
b. Malena
a. Alteration in bowel habits
b. Hematochezia
c. Tenesmus
d. Pain with defecation
 Abdominal pain
 Weight loss

12. Examination
a. General and Systemic examination
b. Abdominal examination
Ascites and Hepatomegaly: signs of metastasis.
Signs of acute bowel obstruction.

13. Examination
Digital rectal examination
• 90% of rectal cancers can be felt by DRE.
Fixation of the lesion to the anal sphincter.
Relationship to anorectal ring.
Fixation to the rectal wall and pelvic wall
Correct and Incorrect method of DRE

14. Investigations
1. . Proctoscopy
• Can accurately determine the distance between
distal tumor margin, top of the anorectal ring, and
dentate line.
2. Flexible sigmoidoscopy

15. Investigations
C. Colonoscopy
Most patients are diagnosed by
colonoscopy after presenting with lower GI
bleeding.
Most tumors appear as an endoluminal
mass arising from mucosa and protruding
in lumen.
The mass may be exophytic or polypoid.
If the mass is noted, a biopsy is taken.

16. Synchronous lesions
• Present in 3-5 % of patients.
• Two or more distinct primary tumors
separated by normal bowel and not
due to direct extension or metastasis.

17. Tumor markers
• Carcinoembryonic antigen (CEA)
Sensitivity: 46%
Specificity: 89%
• Not used as a screening or diagnostic test.
• Preoperative CEA > 5ng/ml has a worse prognosis.
• Elevated preoperative CEA that doesn’t normalize after resection implies
persistent disease.

18. Management

19. Pretreatment staging

20. Imaging evaluation
• MRI of pelvis (3mm)
Preferred imaging for evaluating the
extent of primary tumor.
Provide information on depth of
transmural invasion, presence of
suspicious regional lymph nodes,
status of CRM, and invasion of other
organs.
• Transrectal endoscopic USG
Alternative for early-stage tumors (T1-
2,N0).
For advanced disease, may be limited
by the bulkiness of tumor and lack of
depth to assess invasion of other
organs.

21. Other imaging modalities
• CT scan
Helpful for evaluating distant
metastatic spread and for tumor-
related complications.
Provides limited local tumor and
nodal staging information.
Performed for chest, abdomen, and
pelvis.
• PET scan
Not been shown to add significant
information to conventional imaging
for initial locoregional staging of rectal
cancer.

22. Colorectal cancer staging: AJCC 8th edition
Primary tumor (T)
Tx Tumor cannot be assessed.
T0 No evidence of primary tumor.
Tis Carcinoma insitu(Intramucosal carcinoma).
T1 Tumor invades submucosa.
T2 Tumor invades muscularis propria.
T3 Tumor invades into pericolorectal tissues.
T4a Invades through visceral peritoneum
T4b Invades or adheres to adjacent organs

24. Colorectal cancer staging: AJCC 8th edition
Regional lymph node (N)
Nx Regional LN couldn’t be assessed.
N0 No regional LN metastasis.
N1a One regional LN positive.
N1b Two to 3 regional LN positive.
N1c Tumor deposits in subserosa, mesentery, perirectal
tissue.
N2a Four to six regional LN positive.
N2b Seven or more regional LN positive.

26. Colorectal cancer staging: AJCC 8th edition
Distant metastasis
M0 No distant metastasis.
M1a Mets to one organ without peritoneal mets.
M1b Mets to 2 or more organs w/o peritoneal mets.
M1c Mets to peritoneal surface.

27. Prognostic group staging

28. Neoadjuvant therapy

29. Neoadjuvant therapy: Indications
Patients with clinical T3-T4 tumors: preoperative CRT or rt followed by adjuvant
therapy.
Patients with node (+) disease regardless of primary tumor stage.
The tumor appears to invade the mesorectal fascia.
Poor surgical candidate or decline APR for distal T1-2, N0 tumor.

30. Management of complete clinical responders
• If no evidence of residual tumor on DRE, rectal MRI, and direct endoscopic
evaluation, may be considered for the initial nonoperative approach.
• If nonoperative management is chosen, repeat above mentioned examinations
every 3 months for 2 years; then every 6 months for 5 years.

31. Surgical treatment
• A cornerstone for curative therapy for rectal adenocarcinoma.
• Depending upon the stage, size and location can be treated with local or radical
excision.
• Local excision: Transanally
• Radical excision: Transabdominally
a. Sphincter sparing procedure (e.g. Low anterior resection)
b. Abdominoperineal resection

32. Preoperative preparation
• Counseling and siting of stoma.
• Correction of anemia and electrolyte disorders.
• Arranging and cross-matching blood.
• Bowel preparation.
• DVT prophylaxis.
• Prophylactic antibiotics.

33. Selecting surgical treatment
Distance of cancer from the anal verge.
Presence of invasion into lateral pelvic walls/other organs.
Size of cancer.
Presence of regional lymph node metastasis.
Patient’s pelvic anatomy.
Presurgical anorectal sphincter function.
Whether the patient can tolerate transabdominal surgery.

34. Local excision
Criteria
Superficial T0 or T1 tumor.
Tumor less than 3 cm in diameter.
Involves less than 30% of bowel
lumen circumference.
The tumor is mobile and nonfixed.
Able to achieve clear margins.
Favorable histological features.
No evidence of metastasis.
Compliant with postoperative
surveillance.

35. Local excision: Basis
• Involves full-thickness excision, ideally with a 10 cm grossly normal
circumferential margin.

36. Transanal excision
 Amenable tumors range from 6-8 cm above the anal verge.

37. Transcoccygeal excision
Used for larger or more proximal lesions within middle or distal 3rd of rectum.
Anterior lesion Posterior lesion

38. Transanal endoscopic microsurgery
• Useful for small lesions in the mid and proximal
rectum that are too high for traditional excision.
• Rigid operating proctoscope of diameter 40 mm,
length 12/20 cm used.
• Designed to provide exposure to a lesion that is
down relative to optic scope.

39. Local excision: Outcomes
• Local recurrence
 T1 lesions: 7- 21 %.
T2 lesions: 26-47%

40. Low anterior resection (LAR)
Criteria
Invasive rectal cancer (T2-T4)
If a negative distal margin can be achieved.
Adequate presurgical anorectal sphincter function.

41. LAR: Basis
• Entails partial or total resection of the rectum
followed by colorectal or coloanal anastomosis.
• Total mesorectal excision
Involves sharp dissection in the avascular plane
between fascia propria which encompasses
mesorectum and parietal fascia overlying pelvic
wall structures.
Emphasizes autonomic nerve preservation, and
avoids violation of mesorectal envelope.

42. Patient positioning

43. Mobilization and division of left colon

44. Mobilization and dissection around the rectum

45. Division of rectum and colorectal anastomosis

46. Special considerations
• Diverting loop ileostomy considered for low-lying anastomosis; a/w increased
rates of anastomotic leaks.
• Drain placement is recommended in extremely low resection.
• Anastomosis around the anorectal ring results in impaired QOL.
Colonic pouch
Transverse coloplasty

47. LAR: Outcomes
• The local recurrence rate of less than 10%.
• Lower recurrence a/w use of meticulous surgical techniques (achieving adequate
margins, performing TME and adjuvant chemo radiotherapy.

48. Abdominoperineal resection (APR)
Criteria
• Patients with T2-4 tumor:
A negative distal margin of 1 cm can’t be achieved by any other procedures.
Locally advanced low-lying rectal cancer.
Locally recurrent low-lying rectal cancer.
Poor presurgical anorectal function.

49. APR: Basis
• Entails en bloc resection of sigmoid colon, rectum and anus followed by
reconstruction of a permanent colostomy.

50. Steps in perineal dissection

51. …Steps in perineal resection

52. Postoperative care
• Not allowed to sit for 5 days.
• Perineum cleaned daily with hydrogen peroxide.
• Foley catheterization for 3 -5 days.
• Wound complications in up to 25% of cases.
• Stoma complications: Ischemia, retraction, hernia, stenosis, prolapse
• Operative mortality of APR: less than 2%

53. Multivisceral resection
Criteria
Locally advanced rectal cancer involving adjacent organs or body structures.
Locally recurrent rectal cancer.

54. Multivisceral resection: Basis
• Involves resection of the rectum with one or more adjacent pelvic organs or bony
structures.
• Total pelvic exenteration removes all pelvic organs.

55. Treatment: Newly diagnosed T1 rectal cancer

56. …Newly diagnosed T1 tumor

57. Treatment: Newly diagnosed T2 tumor

58. …Treatment: Newly diagnosed T2 tumor

59. Treatment:Locally advanced tumor( T3/4; N1/2)

60. Adjuvant therapy
• Following resection, all patients who received neoadjuvant should receive 4
months of adjuvant chemotherapy.
• Those with stage 2/3; who directly underwent surgery: 4 months of chemo
followed by six weeks of chemoradiotherapy.

61. Post-treatment Surveillance
Rationale
Early identification of patients who might potentially be cured by further surgical
intervention.
Screen for second primary cancers or polyps.

62. Post-treatment Surveillance: Stage wise
Stage 1 disease
Most don’t require surveillance beyond interval colonoscopy.

63. Post-treatment Surveillance: Stage wise
Stage II/III disease
F/u every 3-6 months first 3 years; then every 6 months during 4th to 5th year.
History and examination (incl. DRE) in each visit.
Serum CEA at each f/u for 1st two to three years.
Colonoscopy within few months after resection; then at 1st year.
Annua CT scan of chest and abdomen for at least 3 years.

64. Post-treatment Surveillance: Stage wise
Resected stage IV disease
No high evidence data for recommendation.
Surveillance strategy individualised.

65. Prognosis

66. References
• National Comprehensive Cancer Committee guidelines 2022.
• European Society of Medical Oncology guidelines 2022.
• Bailey and Love text book of the surgery 28th edition.
• Sabiston textbook of surgery.
• Maingot text book of abdominal operations.

67. Thank You.