Background
Phase III RCT (German Rectal Cancer Study). 823 patients with clinical stage T3-T4 or N+ rectal cancer. Randomized to preoperative CRT followed by surgery and adjuvant chemotherapy, versus surgery followed by postoperative CRT and adjuvant chemotherapy. TME was mandated. This trial established preoperative CRT as the standard over postoperative CRT.
Interventions and follow up
Arm A: Preoperative CRT: 50.4 Gy + 5-FU 1,000 mg/m²/day CI days 1–5 and 29–33 → TME surgery → adjuvant 5-FU × 4 cycle
Arm B: TME surgery → postoperative CRT: 55.8 Gy + 5-FU 1,000 mg/m²/day CI × 2 courses → adjuvant 5-FU × 4 cycle
Primary endpoint: Overall survival
mFollow up: 134 months (11+ years)
Arm B: TME surgery → postoperative CRT: 55.8 Gy + 5-FU 1,000 mg/m²/day CI × 2 courses → adjuvant 5-FU × 4 cycle
Primary endpoint: Overall survival
mFollow up: 134 months (11+ years)
Results
10-yr local recurrence: 7.1% (preoperative) vs 10.1% (postoperative), P=.048
10-yr OS: 59.6% vs 59.9%, P=.85 — no significant difference
10-yr DFS: 68.1% vs 67.8%, P=.65 — no difference
Sphincter preservation: 39% vs 19% in distal tumors (initially planned for APR), P=.004
10-yr OS: 59.6% vs 59.9%, P=.85 — no significant difference
10-yr DFS: 68.1% vs 67.8%, P=.65 — no difference
Sphincter preservation: 39% vs 19% in distal tumors (initially planned for APR), P=.004
Adverse events
Main adverse events: Grade ≥3 acute toxicity: 27% (preoperative) vs 40% (postoperative), P<.001. Grade ≥3 late toxicity: 14% vs 24%, P=.01. Postoperative CRT more toxic.
Conclusions
Preoperative CRT significantly reduced local recurrence (7.1% vs 10.1%) and toxicity compared to postoperative CRT without a survival difference at 11 years. Higher sphincter preservation rates and better tolerability make preoperative CRT the standard approach. No OS benefit was ever demonstrated.
Key Limitations
Key Limitations: No OS or DFS benefit despite reduced local recurrence — suggests local recurrence is not the dominant mode of failure; systemic metastases drive mortality. Adjuvant chemotherapy (5-FU monotherapy) was not optimal by modern standards. Many stage II patients would not require aggressive treatment per modern risk stratification. The trial predates the era of total neoadjuvant therapy and MRI-guided restaging.
Clinical Context
The German trial established preoperative CRT as the standard for cT3-T4/N+ rectal cancer and ended the postoperative CRT era. It also demonstrated significant downstaging and sphincter preservation advantage of preoperative treatment. Modern rectal cancer management has further evolved with total neoadjuvant therapy (TNT — RAPIDO, PRODIGE 23) showing improved pCR rates and potentially improved survival.
References