Journal Club - MRC CR07 lancet 2009
presents a pt with moderately differentiated invasive adeno carcinoma. uT3 by EUS, one 8mm LN. 8cm from verge. What is the ideal sequence of treatment.
Reviewed the Swedish rectal trial. 1187 pt with resectable rectal cancer, randomized to 5Gy x 5 preop vs surgery alone. Improvement in LR, CSS, and OS. Update JCO 2005; 23:5644, looking at R0 surgical subset, all endpoints are maintained. However, no TME was used.
Dutch Rectal trial. All undergoing TME 1861 patients. Randomized to preop 5Gy x 5 vs surgery alone. NEJM 2001;345:368. LR at 6yrs 11% vs 6% p<0.001.
Preop vs Postop: German trial NEJM 2004;351:1731. Preop 50.4Gy with 5FU, vs Postop 55.8Gy with 5FU. LR 13 vs 6% SS. 90% compliance to CT or RT in the preop group, 50% compliance in the postop group.
Are we overtreating some patients. Probably – This MRC trial is aimed at determining this.
1350pts randomize to surgery first with CTRT to follow if margins <=1mm, vs. Preop RT 5Gy x 5. 92% of surgeries were with TME technique. 40% in preop group got chemotherapy, 45% in the postop group got chemotherapy.
Primary endpoint LR, secondary – OS, DFS, toxicities, etc.
Started as a non-inferiority trial, but changed to a superiority trial for 5Gy x 5. 2.5% improvement in LR at 5 years. Margins was 10 vs 12% (NS).
LR HR 0.39 p<0.001. p="0.013." p="0.4).">
Pathologic Assessment (Quirke Lancet 2009). Looked at true TME plane vs intramesorectal vs intra muscularis propria: 3yLR 13% vs 7% vs 4% p=0.0039. In the optimal group: True TME + preoperative RT resulted in 3yr LR of 1%.
So with the staging that was performed, we cannot select patients who do not need RT.