Staging of colon and rectal cancer: from endoscopy to molecular markers.

The primary management of colorectal cancer begins with preoperative diagnosis and the ability to stage the extent of the tumor burden clinically. Endoscopic approaches have been pivotal in this management strategy, and have given rise to endoscopic techniques allowing for primary resection and treatment of metastases. This advance has allowed for the continued development of pathologic staging as used in the tumor node metastasis (TNM) system. The next major milestone in the staging of large bowel cancer will be to blend current anatomic staging strategies with specific molecular markers that will refine subsets appropriate for targeted therapy.