[Evaluation of chemoradiotherapy for the treatment of rectal cancer]

Chemoradiotherapy for the treatment of primary rectal cancers has been regarded as an effective adjuvant for surgical procedures. It has been expected to reduce local recurrence, increase the chance of sphincter-preserving operation and improve survival. However, recent advances in surgical technique for rectal cancers have reduced the local recurrence rate to no more than 10%, where the question may arise of whether adjuvant chemoradiotherapy is indeed necessary. Another matter to be elucidated is why adjuvant chemoradiotherapy does not necessarily improve overall survival for rectal cancers even when the local recurrence rate is reduced. In the treatment of locally recurrent lesions, either heavy ion radiotherapy or proton beam therapy is expected to be an effective alternative to the surgical procedure.