Rectal Cancer

Question 1

What is TME?

Answer 1

Procedure performed during low anterior resection for middle/low rectal tumor, in which mesorectum is removed along with rectum to the level of elevators

Question 2

Evidence for TME

Answer 2

reduce risk of local recurrence 
improves survival (5 year and overall disease free survival) 

Landmark: Heald Lancet 1986)

Question 3

Quirke grading of TME specimen

1) Gradings
2) Criteria
3) Evidence

Answer 3

1) 3-Good, 2-Moderate, 1-Poor
2)
- intactness of mesorectum
- defects in specimen
- bulk
- coning
- irregularity of CRM
3) Quirke 2009 Lancet

Question 4

Clearance margins for rectal tumors

Answer 4

Distal 2cm mucosal margin
Proximal 5cm
CRM >2mm
Excision of CRM 5cm beyond distal margin

Question 5

Defunctioning stoma, pros and cons of

1) loop ileostomy
2) transverse colostomy

Answer 5

1)
+less risk of prolapse
-high output stoma
2)
- prolapse
-risk of compromised marginal artery on closure

Question 6

Low rectal cancer

Answer 6

MRI confirms lower edge of tumor below origins of the levator

Question 7

TAMIS

Answer 7

use of single-site port transanally in conjunction with ordinary laparoscopic instruments/camera, standard lap CO2 insufflator

Question 8

What is the mesorectum?

Answer 8

perirectal tissue composed of fat, lymphatics and blood vessels contained within the endopelvic visceral fascia, extending the whole length of rectum down to pelvic diaphragm and attaches the rectum to pelvic sidewall and sacrum

Question 9

Indications for local excision of early rectal cancer

Answer 9

T1N0 or less
well - mod diff tumor
size < 4cm
clear margin feasible
tumor involving < 30% rectal wall circumference

Question 10

Evidence for MRI for assessment of CRM involvement

Answer 10

MERCURY study (BMJ 2006)

MRI 92% specificity for predictions of clear CRM

Question 11

Preoperative CRT for rectal cancer

1) Advantages
2) Disadvantages

Answer 11

1)
-sterilization fo mesorectal lymphatic channels
-downstaging
-exclusion fo small bowel from radiation field
-superior function of non-irradiated neo-rectum
2)

Question 12

What is SCPRT? What is the regimen?

Answer 12

Short course preoperative radiotherapy

• 25 Gy total dose at 5Gy/fraction during 1 week
• Followed by immediate surgery <10 days after first radiation fraction

Question 13

What is the regimen of long course chemoradiotherapy?

Answer 13

• 1.8-2Gy over 25-28 days with concurrent chemo as radiosensitizer
• Radical surgery delayed for 6-8 weeks

Question 14

What is pCR? What percentage of patients achieve pCR after neoadjuvant chemo?

Answer 14

Pathological complete response

25%

Question 15

T3a

Answer 15

<1mm invasion beyond muscularis propria

Question 16

T3b

Answer 16

1-5mm invasion beyond muscularis propriae

Question 17

T3c

Answer 17

6-15mm invasion beyond muscularis propria

Question 18

T3d

Answer 18

>15mm invasion beyond muscularis propriae

Question 19

What is cCR?

Answer 19

Clinical complete response

• absence of any palpable tumour or
• no irregularity at DRE,
• no visible lesion at proctoscopy except a flat scar/ telangiectasia / whitening of the mucosa.

Question 20

What is watch and wait approach?

Answer 20

Non operative strategy of intensive surveillance after achieve pCR

Question 21

What is the optimal time after CRT for surgery?

Answer 21

6-12 weeks

Shorter: inadequate tumour shrinkage, side effects from CRT

Longer: fibrosis leading to higher surgical morbidity, disease progression

Question 22

Theoretical advantages of neoadjuvant chemoradiotherapy

Answer 22

• downstaging to allow resectiability + sphincter preservation
• sterilization of mesorectal lymphatics
• radiosensitizer
• better function of the non-irradiated neorectum

Question 23

Theoretical disadvantages of preop CRT

Answer 23

• Pathological understanding leading to subsequent under-treatment
• tumor progression between period of neoadjuvant tx and surgery
• perioperative complications

Question 24

Choice of chemotherapy with RT

Answer 24

Fluoropyrimidine

• 5-FU
• Capecitabine

Question 25

Choice of chemotherapy with RT

Answer 25

Fluoropyrimidine * 5-FU * FOLFOX: infusional 5FU * XELOX: infusional + oral * FLOX: bolus 5FU * Capecitabine

Question 26

Evidence for SCPRT

Answer 26

* Swedish Rectal Cancer Trial 1997 NEJM * Dutch TME Trial 2001 NEJM * MRC (CR07) -NCIC (CTGC016)

Question 27

Evidence for long course CRT

Answer 27

* German Rectal Cancer Study Group 2004 NEJM * NASBP R-03 * Korean trial

Question 28

What is TNT?

Answer 28

Total neoadjuvant therapy ## Footnote oxaliplatin-based chemotherapy combined with long-course CRT or short-course RT for locally advanced rectal cancer, with high risk for margin positive resection

Question 29

Complications of acute toxicity in RT

Answer 29

* GI disturbance * Radiation enteritis * Lethargy/weakness * Leukopenia * Skin reaction

Question 30

Late complications of RT

Answer 30

* Bowel stricture * Chronic diarrhea * Thromboembolism * AVN of hip * Secondary cancer * Pelvic floor dysfunction * Infertility/ Erectile Dysfunction / Dyspareunia

Question 31

Purposed of colonic stenting

Answer 31

Bridge to surgery Palliative intent

Question 32

Advantages of stenting for bridge to surgery?

Answer 32

* Convert emergency to elective, reduce surgical mortality * Allow nutrition boost * Time for full bowel evaluation * lower stoma rate

Question 33

Risks of stenting

Answer 33

* Perforation 5% * Bleeding 5% * Stent migration 5-10% * Stent occlusion * Technical success 70-90% * Mortality 0-1 %

Question 34

Time to surgery after stenting

Answer 34

5-10 days (ESGE guidelines) Some centres up to 2-4 weeks

Question 35

Concerns with stenting

Answer 35

Oncological risk: Several RCT/prospective studies show higher recurrence rate No different in overall survival

Question 36

Would you recommend stenting as bridge to elective surgery?

Answer 36

In general as evidence points to worsening disease free survival, stenting as bridge to elective surgery **not recommended** compared to emergency surgery EXCEPT in selected cases of **left sided obstructing tumor** where patient **high risk of postoperative mortality** (ASA III, Age \> 70)

Question 37

Contraindications to stenting

Answer 37

Peritonitis Suspected perforation Low rectal tumors

Question 38

Median duration of stent patency

Answer 38

106 days (68-288)

Question 39

Surveillance after resection of colorectal cancer

Answer 39

* FU 4-6wks after surgery * Minimum 2 sets of CT TAP in first 3 years * CEA at least 6mthly in first 3 yrs * CLN 1 year after OT then 5 years then dependent on CLN findings * Reinvestigate prn if clinical/ radiological/ biochemical suspicious of recurrence

Question 40

What is the management of local recurrent of rectal cancer?

Answer 40

* MDT * Curative surgery vs +/- neoadjuvant if no hx of RT * Aim R0 resection * Inoperable =\> palliative CRT