Neo-adjuvant Short Course Chemo-radiation Therapy in Locally Advanced Rectal Cancer Patients

Description

Neo-adjuvant radiotherapy is associated with the improvement of local control for rectal cancer. For locally advanced stage II-III resectable rectal cancer, either preoperative short-course radiotherapy of 25 Gy in 5 consecutive days or long-course chemo-radiotherapy followed by radical Total Meso-rectal Excision is recommended. The Swedish Rectal Cancer Trial has demonstrated the lower rate of early toxicity of short course radiotherapy when compared to chemo-radiation. Short-course irradiation reduced the risk of local recurrence with evidence of overall survival improvement. Short-course regimen is less expensive and more convenient, especially in centers with long waiting lists. Two meta-analyses showed that short course is as effective as long course chemo-radiation in the management of locally advanced rectal cancer in the terms of sphincter preservation rates, down-staging, R0 resection, local control, and grade 3-4 toxicity. Despite reduction in local-regional recurrence risk with neo-adjuvant short course radiotherapy, distant disease recurrence remains a substantial risk for patients with locally advanced disease. In a controlled randomized trial, a short course radiotherapy followed by consolidation chemotherapy prior to surgery yielded superior overall survival outcomes compared to chemo-radiotherapy, without significant differences in disease-free survival, nor local or distant disease control rates. The phase III RAPIDO and STELLAR clinical trials are also evaluating short course radiotherapy and consolidation chemotherapy. The Stockholm III trial was a 3-arm trial that compared short-course RT with the standard 1-week delay to surgery, short-course RT with a 4- to 6-week delay to surgery, and long-course chemoradiation with a 4- to 6-week delay to surgery. The results show similar outcomes between the groups, but delaying the surgery after short-course RT decreased the rates of high-grade toxicity and allowed for an expedited treatment program.

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