Maintenance Therapy in Colorectal Cancer: Moving the Artillery Down while Keeping an Eye on the Enemy

The survival improvement in metastatic colorectal cancer, achieved with more intensive chemotherapy regimens, has recently led clinicians to question the optimal duration of therapies and to consider the role of maintenance. Indeed, patients whose disease is controlled after induction chemotherapy may benefit from continuing a less intensive regimen in order to reinforce the results achieved with up-front treatment. In addition, the more favorable toxicity profile of maintenance approaches would ensure a better quality of life. After discussing the rationale and the difference of pursuing a maintenance strategy with chemotherapeutic and/or biologic agents, we present significant available data from the literature and comment on the current implications and future directions of maintenance therapy. The current roles of depotentiated treatment schedules, antiangiogenic compounds, epidermal growth factor receptor inhibitors, and novel targeted therapies are also reviewed. Finally, we address elements that may foster clinical and social debate on this topic, suggesting potential aspects that need to be further investigated.