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.

 

 

Rectal Cancer - Chemoradiotherapy

Rectal Cancer:

5y OS:
I 90-95%
II 75-95%
III 40-70%
IV 5%

Local Excision

RTOG 8902: Postoperative study. Low risk <3cm, T1, Gr 1-2, no LVSI, nl CEA. Treated with Observation after Local Excision 4% failure in T1. T2 and T3 were given CTRT and failure rates were 20-30%.

CALGB Local Excision update: Updated 2008
T1s were observed, T2 treated with postoperative CTRT after local excision. 10year LR for T1 were 8%; in T2 the rates were 18%, with a number of late local recurrences. This calls into question the ability to treat T2 tumors with local excision even with postoperative treatment.

MSKCC series (Paty, Ann Surg, 2002). Failure rates after LE were ~10% in T1, ~25% in T2 wether or not RT+/- chemotherapy was given.

T3-4:
Local Recurrence without further treatment beyond surgery was 25-40% in the pre-TME era. This is improved to 10-15% with TME technique.

Postop Data:
Oconnell NEJM 1994: Postoperative T3-T4 or N+ rectal cancer (n=666), randomized to RT with concurrent PVI vs bolus FU. Improved RFS and OS in the PVI group.

Smalley JCO 2006: Intergroup 0144 compared three different concurrent chemotherapy regimens. CI still looked better for LC and for heme toxicity (other arms were two different bolus regimens).

Preop Data:
Swedish Preop Trial (NEJM 1997):
n=1,168 T3+ or N+ treated in the preTME era. Randomized to preoperative RT 5Gy x 5 vs. observation. This is the only trial to show not only a LC benefit, but also an overall survival benefit to preoperative RT.

Dutch TME trial (Ann Surg, 2007)
n=1,861 all treated with TME, randomized to preoperative RT (5Gyx5) vs no neoadjuvant treatment. 5y LR 11% vs 6% (SS). No difference in overall survival. This is important in that it proved that RT was still needed for optimal local control, even after optimized surgery.

German Preop vs Postop Trial (NEJM 2004)
n=823, T3+ or N+. Randomized to preoperative CTRT (50.4Gy) with CI 5FU, or postoperative CTRT (55.8Gy) with CI 5FU. OS and DFS not different. 5 year Local Control 6 vs 13% (SS). Both acute and late toxicities were better with preoperative treatment. More sphincter preserving therapy in the preop group, in the subgroup that were determined not to be candidates prior to treatment (19 vs 39%, SS).

EORTC 22921 (NEJM 2006)
n=1,011. T3+, randomized to four arms, all recieved preop RT. The analysis is confused due to the multiple arms, but the take home is that chemotherapy is necessary, wether concurrent or postoperatively. LC was worse in the single arm that had no chemotherapy.

FFCD 9203 (JCO 2006)
T3-4 recieving preoperative RT then randomized to concurrent vs sequential chemotherapy. LC 17% vs 8% p=0.04. This proves the need for concurrent chemotherapy with Preoperative treatment.

Polish trial (B J Surg, 2006)
T3-4 n=2 randomized to 5Gyx5 or 50.4Gy with 5FU preoperatively. Higher toxicity in the CTRT arm. No difference in OS, DFS or LC. No difference in sphincter preservation. This trial is interesting in that it shows equivalence in a short course treatment and the more conventional prolonged CTRT approach. An additional article looking at late toxicities showed no difference between the arms (Rad Onc 2007).

Our approach-
EUS should be obtained in the majority of patients.

T1: Surgery alone. local excision can be considered an option, with careful consenting.

T2: Would reccomend more definitive TME surgery over local excision with postop CTRT.

T3-T4 or N+: Preoperative CTRT- WPRT to 45Gy in 1.8 Gy/fx, with concurrent CI 5FU or capecitabine, usually treated prone with a three field technique (PA, two laterals). An additional 5.4 Gy is delivered with lateral reduced fields, excluding small bowel, to the tumor and associated mesorectum/presacral region. Surgery with TME technique is then reccomended 6-8 weeks thereafter.