730 Pre-operative radiotherapy to prevent loco-regional recurrence in rectal carcinoma

Aim of study To analyze local control rate and survival of a series of patients included in a phase I–II pilot study. Patients and treatment Between 1980–92, 170 patients were included. Median age: 61 Y, sex ratio: 1.7 M/F. All patients with proven adenocarcinoma (7% poorly differentiated) of the rectum. Clinical stage: T2: 68, T3: 85, T4: 17. After irradiation and surgery pathological staging was: pT0: 24, pTl: 22, pT2: 43, pT3: 73, pT4: 8, pNO: 128, pN1: 42. Radiotherapy (RX) was given with a patient in the prone position. 3 fields technique 18 MV × rays. Accelerated schedule: 39 Gy/13F/17 days. Surgery performed between 1 to 9 weeks after the end of RX. No chemotherapy. Results Median followup: 50 months. Overall survival: 71%, 5 years. Actuarial probability of pelvic relapse 10% 5 years. For pT0-1–2 the local control probability is 96% but T4 have a risk of local relapse of 26%. Local relapse at 5 years is 5% in pNO but 42% for pN1–2. Overall survival at 5 years is strongly correlated with pN: 87%. pNO vs 36% for pN1–2. In 62% of patients a restorative surgery was possible with a 8% risk of fistula. Operative mortality was 2%. There was no grade 3 radiation late toxicity. Conclusion Accelerated preoperative RX limited to the posterior pelvis is well tolerated. It appears to decrease local pelvic relapse and may be to increase the chances of sphincter preserving surgery. Its role on survival is still debated.