rectal cancer

Question 1

Hereditary syndromes:
-causes
-types

Answer 1

-cause 10-15% of colorectal cases
-Lynch Syndrome (1 in 300)
APC gene (1 in 7000)

Question 2

Screening:
why ?

Answer 2

-75% of patients have no apparent risk factors except older age
- 5-yr survival < 60% in most EU countries

Question 3

screening:aim

Answer 3

Detect localised cancers or pre-malignant adenomas from which 80% of cancers arise

Question 4

ireland bowel screening programme

Answer 4

-Free
-men and women 60-69
-Home test kit (Faecal Immunochemical Test-FIT )
-every 2 years

Question 5

Pathology

Answer 5

-Adenocarcinoma (95%)
-Other
§ Squamous Cell Carcinoma
§ Small cell
§ Undifferentiated
§ Lymphoma
§ Carcinoid

Question 6

Cancer of the rectum is defined as

Answer 6

from the rectosigmoid junction(S3) to anus

Question 7

Presenting Signs and Symptoms

Answer 7

-abdominal pain
-changes in bowel habits
-bleeding on defaeacation
-unexplained anemia

Question 8

Rectal Cancer:
Natural History

Answer 8

-Local invasion
◦ Within wall
◦ Through wall
-Lymphatic invasion
-Distance metastases
◦ Rectal cancer: lungs > liver

Question 9

Goal of staging

Answer 9

-depth of tumour penetration
-lymph node involvement
-extensive mets

Question 10

Pelvic MRI

Answer 10

indicated
shows relationship of tumour to:
-muscularis propia
-extension of rectal wall
-mesorectal fascia MRF
-involvement of lymph nodes and vessels

Question 11

CT

Answer 11

indicated
detects metastatic disease in nodes, liver and lungs

Question 12

Assessment of the Circumferential Resection Margin (CRM)

Answer 12

depth of penetration of tumour thru rectal wall

defined surgically by dissection

Question 13

how is the assessment carried out

Answer 13

imaging b4 surgery, reported on MRI as distance to mesorectal fascia (MRF)

Question 14

CRM is a Key prognostic indicator.. why?

Answer 14

+ CRM increases the risk of recurrence by 3.5-fold
and doubles the risk of death from disease

Question 15

CRM involvement on MRI is normally defined as

Answer 15

distance from tumour to MRF of <1 mm

This indicates that there is a risk that the CRM will be involved after surgery …ie clear margins cannot be achieved

tumour downstaged before surgery if possible because at surgery, MRF is the resection plane and it has to be tumour-free

Question 16

CRM NEGATIVE

Answer 16

distance between the tumour and MRF > 2mm

Question 17

Other Workup pt1

Answer 17

-Colonoscopy
-family / medical history
-biospy

Question 18

Other Workup pt2

Answer 18

-DRE=Most accurate for defining the location of mid and lower rectal tumours

-FBCs= Tumour marker: serum CEA (carcinoembryonic antigen)
…. Preop CEA >5ng/mL have a worse prognosis stage for stage

Question 19

Traditional Treatment Options:
Neoadjuvant

Answer 19

-CRT
-RT
-none

Question 20

Traditional Treatment Options:
definitive

Answer 20

surgery

Question 21

Traditional Treatment Options:
Post-op Adjuvant Therapy

Answer 21

observation
CRT
chemo

Question 22

Types of Surgery

Answer 22

1.local extension
2.Trans-abdominal resection
a) Sphincter-preserving resection
b) Abdominal perineal resection (APR)

Question 23

Criteria for surgical option:

Answer 23

◦ Depth of tumour invasion and MRF involvement
◦ Size
◦ Tumour location
◦ Regional lymph node involvement
◦ Invasion of adjacent pelvic organs

Question 24

Local Excision

Answer 24

-Transanal endoscopic microsurgery (TEM) may be
used
-Minimally invasive
-local excision of rectal cancer between 4cm to ~8cm from the anal verge
-No lymph nodes removed

Question 25

Criteria for local excision

Answer 25

-Superficial T0 or T1
-<30% circumference of bowel
-Within 8cm of anal verge
-Well to moderate differentiated
- <3cm in size
-N0

Question 26

2 types of trans-abdominal resection:

Answer 26

A. Sphincter-preserving resection (including TME)
B. Abdominoperineal resection (including TME)

Question 27

Principles of Resection

Answer 27

◦Invasive cancer cT2-4
◦ Wide resection to achieve negative margins
◦ A total mesorectal excision (TME) and resection of local lymph nodes w A or B
◦ Anorectal sphincter function should be preserved if negative distal margins can be achieved for a

Question 28

Examples of sphincter-sparing procedure :

Answer 28

◦ Low anterior resection (upper to middle 1/3)
◦ Very low anterior resection (distal rectum)

Question 29

Criteria for performing sphincter-sparing procedure :

Answer 29

-Invasive beyond the submucosa
- negative distal margin

Question 30

Criteria for performing: Abdominoperineal resection

Answer 30

-If negative distal margin (1-2cm) of resection cannot be achieved with a
-Salvage procedure for local recurrence or locally advanced rectal cancer
-Includes TME

AKA Permanent colostomy

Question 31

Total Mesorectal Excision (TME)

Answer 31

-reduces local recurrences and perioperative morbidity

• if resection margin is free of tumour…best surgical treatment

Question 32

Surgery and Site:Upper Third

Answer 32

Anterior or low anterior resection

Question 33

middle Third

Answer 33

Very low /Low anterior resection

Question 34

Lower Third

Answer 34

Very low anterior resection
APR

Question 35

Why does Low rectal cancer have a higher local recurrence rate ?

Answer 35

-distal tapering of the mesorectal fat tf more easily invades the mesorectal fascia, pelvic wall and surrounding organs
-more difficult to get a tumour free resection