Cancer of the rectum continues to be a significant health problem in industrialized co- tries around the world. Relative 5-year survival rates in the USA for cancer of the rectum from 1995 to 2001 improved to 65%, a 15% improvement over 20 years (American Cancer Society, 2007). The reasons for this dramatic improvement include more accurate pr- perative staging, aggressive neoadjuvant therapy and improved surgical technique as well as specialty-trained surgeons. Despite advances in nonoperative techniques of radiation therapy, chemotherapy and immunotherapy, surgical extirpation continues to be the cornerstone of curative treatment of this potentially lethal disease. Radical cancer excision with total mesorectal excision has become the preferred surgical procedure for even early-stage cancers of the rectum. Over the past decade the enthusiasm for local excision (and other local treatments) has given way to persuasive (predominantly retrospective) evidence that the incidence of locoregional recurrence due to unsuspected lymphatic metastases and positive lateral margins is un- ceptably high even for stage T tumors. Vigorous attempts to find characteristics of the 1 tumor that would allow successful local treatments are ongoing.

Cancer of the rectum continues to be a significant health problem in industrialized co- tries around the world. Relative 5-year survival rates in the USA for cancer of the rectum from 1995 to 2001 improved to 65%, a 15% improvement over 20 years (American Cancer Society, 2007). The reasons for this dramatic improvement include more accurate pr- perative staging, aggressive neoadjuvant therapy and improved surgical technique as well as specialty-trained surgeons. Despite advances in nonoperative techniques of radiation therapy, chemotherapy and immunotherapy, surgical extirpation continues to be the cornerstone of curative treatment of this potentially lethal disease. Radical cancer excision with total mesorectal excision has become the preferred surgical procedure for even early-stage cancers of the rectum. Over the past decade the enthusiasm for local excision (and other local treatments) has given way to persuasive (predominantly retrospective) evidence that the incidence of locoregional recurrence due to unsuspected lymphatic metastases and positive lateral margins is un- ceptably high even for stage T tumors. Vigorous attempts to find characteristics of the 1 tumor that would allow successful local treatments are ongoing.