Colorectal cancer: Gastrointestinal tumor study group modification of dukes staging system
To grade colorectal cancer in patients for adjuvant therapy
In this system, the depth of penetration of the bowel wall does not affect the classification of stage C tumors
Patients of which the tumor has extended beyond the muscularis into the perirectal fat or patients with regional lymph nodes are considered as having occult disease
These patients are considered candidates for adjuvant therapy