Learning curve: the surgeon as a prognostic factor in colorectal cancer surgery.

The individual surgeon is an independent prognostic factor for outcome in colorectal cancer surgery. The surgeon's learning curve is therefore directly related to the patient's outcome. The exact shape of the learning curve, however, is unknown. The present study reviewed supervision, training/teaching, specialization, surgeon's caseload, and hospital's caseload as the five main surgeon- and hospital-related confounding factors for outcome, and examined their influence on the learning curve as well as their interactions and prognostic significance. All five confounding factors were related to outcome. The highest degree of evidence, however, was found for training/teaching (introduction of total mesorectal excision), specialization in colorectal surgery (special interest, board-certification, specialized colorectal cancer units), and the surgeon's caseload. Five surgeon- and hospitalrelated factors directly influence the surgeon's learning curve and are therefore rightly considered predictors of outcome in colorectal cancer surgery. Improvements in supervision, training/teaching, specialization, the surgeon's caseload, and the hospital's caseload will therefore translate into enhanced patient outcome.