Guidelines 2000 for colon and rectal cancer surgery

Background: Oncologic resection techniques affect outcome for colon cancer and rectal cancer, but standardized guidelines have not been adopted. The N ational Cancer Institute sponsored a panel of experts to systematically rev iew current literature and to draft guidelines that provide uniform definit ions, principles, and practices. Methods: Methods were similar to those des cribed by the American Society of Clinical Oncology in developing practice guidelines. Experts representing oncology and surgery met to review current literature on oncologic resection techniques for level of evidence (I-V, w here I is the best evidence and V is the least compelling) and grade of rec ommendation (A-D, where A is based on the best evidence and D is based on t he weakest evidence). Initial guidelines were drafted, reviewed, and accept ed by consensus, Results: For the following seven factors, the level of evi dence was II, III, or IV, and the findings were generally consistent (grade B): anatomic definition of colon versus rectum, tumor-node-metastasis stag ing, radial margins, adjuvant RO stage, inadvertent rectal perforation, dis tal and proximal rectal margins, and en bloc resection of adherent tumors, For another seven factors, the level of evidence was II, III, or IV, but fi ndings were inconsistent (grade C): laparoscopic colectomy; colon lymphaden ectomy; level of proximal vessel ligation, mesorectal excision, and extende d lateral pelvic lymph node dissection (all three for rectal cancer); no-to uch technique; and bower washout. For the other four factors, there was lit tle or no systematic empirical evidence (grade D): abdominal exploration, o ophorectomy, extent of colon resection, and total length of rectum resected , Conclusions: The panel reports surgical guidelines and definitions based on the best available evidence. The availability of more standardized infor mation in the future should allow for more grade A recommendations.