LONG-TERM RESULTS OF PREOPERATIVE RADIATION-THERAPY ALONE FOR STAGE T-3 AND T-4 RECTAL-CANCER

Background There has been a resurgence of interest in the use of preop erative radiation therapy, with or without chemotherapy, for locally a dvanced rectal cancer. The purpose of this study was to analyse the ti me course and pattern of failure for 74 patients with clinical stage T -3 or T-4 (cT(3-4)) rectal cancer treated with preoperative radiation therapy for whom long-term follow-up was available. Methods Seventy-fo ur patients with cT(3-4) rectal cancer received a median of 45.0 Gy ra diation alone followed by surgery 4-8 weeks later. Median follow-up wa s 90 months; two-thirds of patients were followed for at least 60 mont hs. Results Following radiation therapy the pathological stage was 4 p er cent pT(0), 26 per cent pT(1-2) and 70 per cent pT(3-4). Thirty-two per cent had involved lymph nodes. The actuarial 5-year rates of loca l control, freedom from distant metastasis and disease-specific surviv al were 80, 64 and 73 per cent respectively. The corresponding 10-year rates were 73, 51 and 50 per cent. Median times to detection of local and distant recurrence were 34 and 24 months respectively. Eighty per cent of local recurrences were detected within 54 months; 80 per cent of distant recurrences were detected within 57 months. Conclusion In this analysis, the time to detection of both local and distant recurre nces following preoperative radiation therapy for advanced rectal canc er was surprisingly long. Almost 5 years (57 months) of follow-up were required to detect 80 per cent of all failures. The 5-year local cont rol rate of 80 per cent compares favourably with that achieved by more aggressive chemoradiation regimens for fixed cancers; however, the hi gh distant failure rate with radiation therapy alone suggests that adj uvant systemic therapy should be investigated.