Amos E H, Mendenhall W M, McCarty P J, Gage J O, Emlet J L, Lowrey G C, Peterson C A, Amos W R
Department of Radiation Oncology, West Florida Cancer Institute, Pensacola 32514-6050, USA.
Ann Surg Oncol. 1996 Sep;3(5):431-6. doi: 10.1007/BF02305760.
The role of adjuvant postoperative radiotherapy for locally advanced colon cancer is not well documented.
Seventy-eight patients who underwent a complete resection of B2-C colon cancer received postoperative radiotherapy. Twenty-eight patients received < or = 45 Gy; 50 patients received 50-55 Gy. Twenty-seven patients received adjuvant fluorouracil-based chemotherapy. All patients were followed for a minimum of 3 years; no patients were lost to follow-up.
The overall local control rate was 88%. The 5-year actuarial rate of local control was 96% after 50-55 Gy postoperative radiotherapy compared with 76% after < 50 Gy (p = 0.0095). Multivariate analysis of local control showed that only radiotherapy dose significantly influenced this end point. Cause-specific survival rates at 5 years were B2, 67%; B3, 90%; C1, 100%; C2, 61%; C3, 36%; and overall, 63%. Multivariate analysis of cause-specific survival showed that only stage significantly influenced this end point. Bowel obstruction caused by adhesions developed in three patients and required a laparotomy; radiation-induced sarcoma developed in one additional patient.
Postoperative radiotherapy appears to reduce the risk of local recurrence in patients with locally advanced colon cancer. The optimal dose is probably 50-55 Gy at 1.8 Gy per fraction. Postoperative radiotherapy may improve cause-specific survival for patients with stages B3 and C2 cancers.
