Alternative Surgical Approaches for Rectal Cancer

Dr. John Migaly - general surgeon at Duke talks about Surgical Approaches for Rectal Cancer.

Rectal Overview

40k cases in us, 8k deaths per year

local recurrence in 10-40%

sexual dysfunction is a risk with surgery and should be evaluated preopertatively

7% risk of synchronous carcinoma, 30% risk of synchronous adenomatous change, therefore colonoscopy recommended.

 

Standard Approaches

• T1 - transanal excision can be considered in T1
  

• T2 - radical resection +/- postop RT
  

• T3 or N1, or greater - preop CTRT followed by radical resection
  

 

EUS

Due to this EUS is necessary for appropriate selection T stage accuracy 83%, N stage accuracy 75%, however, this is extremely operator dependent.

T stage is usually overstaged with EUS, usually with T2s being read as T3.

MRI with coil may be close to EUS, perhaps slightly better for N stage.  This is being be utilized in the UK in particular to direct treatment selection.  According to CW, LP and the speaker, this should be considered more in the US.

 

TME

Reviewed Dr. Heald's advocacy of the TME technique. (TME - Total Mesorectal Excision)

Mesorectum - LN, tumor foci, local extension, site of ECE from nodes.  Bounded by Denonviller's Fascia.

Lateral resection margins are important for survival and local control.  <1mm margins - 40% LR, >1mm margins 15% LR.  Similarly overall survival is improved with <4mm margings (Cawthorn, lancet 1990).

Arbmann BJS 1996 - TME improved LR and OS.

Stockholm I-II - (Martling, Lancet 2000) trials of preop RT followed by surgery.  TME was taught to all surgeons participating in the TME project.  both TME and RT greatly improved LRC in cross trial comparison.  APR rates also dropped from 60% to 27% when TME adopted.

 

Dutch TME trial proved the improvement in LRC with RT preoperatively (5Gy x 5), compared to TME alone.  MRC trial also demonstrates this as well.

 

CW brings up the risk of leaks with TME and diverting colostomies.  Diversion results in leak rates of ~5%, which is an improvement from prior.  We may be detecting more radiographically evident leaks with the adoption of regular CT scans in the post op setting, though clinically these may never have been relavent.

 

TME needs to be standard, but penetrance in the community is lagging.  Experience matters (K. Ludwig paper out of Duke shows ~5 fold improvement in sphincter preservation when >10 rectal resections are performed/year, compared to <3).

 

Need 1-2 cm margin to perform LAR, otherwise APR necessary.

 

Reconstruction

J-pouch or side to end are primary options for rectum reconstructions.  Transverse coloplasty another option.  Leaks will often occur at the most caudal end of a J pouch.  Straight colo-anal anastomosis has poor reservoir capabilities.  Note if 6-8cm of rectum left, J-pouch probably not necessary.

Lightning Review of RCTs (Randomized Controlled Trials)

1. J-pouch vs straight coloanal RCT - 89 pts (Hallbook, Ann Surg, 1996): Improvement in QOL with J-pouch.
   

2. J-pouch vs coloplasty RCT - More leaks
   

3. J-pouch vs side to end RCT - No difference
   

 

Laparoscopic TME:

Meticulous technique necessary, visualization may be superior.  Instrumentation improving.  Trendelenburg positioning necessary as this reduces the amount of small bowel in the field.  Outcomes still coming in.  Leak rates reported from 5-20%.  Early reports from 2000 demonstrate a steep learning curve.  In modern series, LRC has been as expected.  Selection key - need a non-obese patient, a non-bulky tumor.  Cosmesis, recovery, and length of stay improved.

 

ACOSOG Z6051 RCT of open vs lap TME resection for T1-3N1 or T3 rectal tumors less than 12cm from verge.  Goal accrual 440.  To open soon.  Primary endpoint will be margin status.

 

Local Excision:

Goal is a minimally invasive procedure to perform a full thickness bowel wall resection with good longitudinal margins along the bowel wall.

 

Unfortunately I missed this bit of the talk, but I think the best data is from the CALGB 8984 prospective trial of local excision in T1 and T2 tumors.  Selection: tumors must be <=10cm from verge,  <= 4cm in size, <=40% of circumference.  T1 tumors were treated with LE alone, and T2 tumors received postoperative CTRT (54Gy with 5FU 500mg/m2 x 2 cycles).  Local recurrence was acceptable in T1 tumors 8% at 10years, however in T2 LRF was 18% at 10 years.  Therefore LE may be considered for T1, appropriately selected, but not routinely for T2.