Intensive or not surveillance of patients with colorectal cancer after curative resection.

It is common practice to follow patients with colorectal cancer for some years after resection and/or adjuvant treatment. Data are lacking about how often patients should be seen, what tests should be performed, and what surveillance strategy has a significant impact on patient outcome. Seven randomized trials have addressed this issue, but none had sufficient statistical power. Four published meta-analyses have established that overall survival is significantly improved for patients in the more intensive programs of follow-up. This improvement amounts to a risk difference of 7% (95% CI: 3%-12%, P = 0.002) in 5-year survival. This should be partly attributable to more frequent reoperation for cure of asymptomatic recurrence, or more intense follow-up, as well other factors, such increased psychosocial support and well-being, diet and lifestyle optimization, and/or improved treatment of coincidental diseases. A large-scale multicenter European study [Gruppo Italiano di Lavoro per la Diagnosi Anticipata (GILDA)] is underway to answer the question of what constitutes optimal surveillance for patients after primary therapy, based on an adequately powered study.