| [ Summary ] |
In the surgical treatment of colorectal cancer and rectal cancer rectal has higher local recurrence rates than colonic cancer. Therefore, in resectable rectal cancer, radiotherapy is performed as an adjuvant therapy to reduce postoperative local recurrence. Previous randomized controlled studies have shown that adjuvant radiotherapy or chemoradiotherapy for rectal cancer decreases local recurrence rates. In relation to survival rates, Swedish Rectal Cancer Trial has shown improvements in five year survival rates by using preoperative radiotherapy. However, at the present time, it is still controversial as to whether radiotherapy improves postoperative survival rates for rectal cancer. In Japan, instead of radiotherapy, lateral node dissection has been widely performed to reduce local recurrence rates of rectal cancer. However, urinary and sexual dysfunction are known to be complications of lateral node dissection. Therefore, in order to preserve urinary and sexual functions, preoperative radiotherapy has been suggested as a possible alternative modality in place of lateral node dissection. On the other hand, in the treatment of nonresectable or recurrent rectal cancer, radiotherapy mainly performed to control tumor related symptoms, such as pain or bleeding. Randomized controlled studies have shown that there was no significant difference in efficacy between radiotherapy and chemoradiotherapy in the treatment of nonresectable rectal cancer. |