Multidisciplinary management of patients with advanced rectal cancer.

The chance of lymph node involvement in T(3) and T(4) rectal cancers is 20% to 60%, a risk sufficiently high that most clinicians favor mesorectal excision rather than less aggressive approaches. Patients who have a complete clinical response of the primary lesions to neoadjuvant therapy may represent a special case. Total mesorectal excision can be accomplished without sacrifice of the anal sphincters, and continence can be preserved. Evolving understanding of patterns of tumor spread and mechanisms of anal continence have resulted in increased use of continence-preserving procedures. Removal of the anal sphincters seems to be advantageous only if the sphincters are directly involved. A few small series suggest that a segmental sphincter resection could result in good local control and continence preservation, even if the sphincters are involved. Areas of controversy currently include the role of neoadjuvant therapy for high rectal lesions, the role of lateral lymph node dissection, and methods of improving anal continence after rectal resection.