High-dose preoperative radiation and the challenge of sphincter-preservation surgery for cancer of the distal 2 cm of the rectum.

PURPOSE: Sphincter-preserving surgery for the management of distal rectal cancer is gaining recognition as an alternative to abdominoperineal resection and loss of anal function. The use of high-dose preoperative radiation appears to enhance the options for sphincter preservation, even in the most distal segments of the rectum.
MATERIALS AND METHODS: Seventy patients with tumors located in the distal 2 cm of the rectum received a minimum dose of 40 to 45 Gy over 4 1/2 weeks at 1.8 to 2.5 Gy per fraction. Patients with unfavorable tumors were given an additional boost of 10 to 15 Gy. Surgery was performed 5 to 10 weeks following completion of radiation. Radical surgical resection was performed in 48 patients and full thickness local excision in 22. Follow-up ranged from a minimum of 1 year to a maximum of 10 years, with a median of 4 years.
RESULTS: There was one perioperative mortality. Two patients did not have their colostomy closed because of complications. Late diversion was required in 4 patients, primarily for recurrent disease. Sixty patients (86%) maintained long-term satisfactory sphincter function. Local recurrence was observed in 9 patients (13%) and distant metastases in 12 patients (17%). The overall five-year actuarial survival rate was 82%. The 5-year survival and local recurrence for postradiation pathological stage of disease was: T0, T1, T2, N0--95% and 8%, T3, T4, N0--91% and 4%, T(any) N+--50% and 41%, respectively.
CONCLUSION: High-dose preoperative radiation, in properly selected patients with rectal cancers of the distal 2 cm, offers opportunities for sphincter-preserving surgical resection with excellent local control, survival, and enhanced quality of life.