Low dose postoperative adjuvant radiation therapy for rectal cancer is ineffective

Ninety-seven patients with rectal cancer which had either penetrated through the rectal wall or involved regional lymph nodes received postoperative adjuvant radiation therapy of 24 Gy in 12 fractions or 25 Gy in 10 fractions in 2 weeks. The crude pelvic recurrence rate was 48/97 (49%) and the actuarial local relapse-free rate at 5 years was 41%. The radiation doses used produced no late morbidity, but had no discernible effect on the risk of local recurrence, and may have compromised the subsequent use of radiation for symptomatic pelvic recurrence.