76

Induction therapy in non-resectable metastatic colorectal cancer is most often based on a bi- or tri-chemotherapy regimen combined with targeted therapy using anti-VEGF or anti-EGFR monoclonal antibody, depending on the RAS and BRAF status. In patients whose disease is controlled after induction therapy, the question arises of therapeutic de-escalation to reduce treatment-related side effects and improve quality of life with no detrimental effect on survival. Several randomized studies have demonstrated the feasibility of therapeutic de-escalation compared to continuing induction chemotherapy until disease progression, with a significant reduction in toxicities, with no impact on overall survival. Based on progression-free survival benefit, there is currently a consensus in favor of maintenance therapy with fluoropyrimidine combined with bevacizumab or an anti-EGFR. However, no study has convincingly demonstrated a significant benefit of such treatment on overall survival compared to monotherapy or even a therapeutic break. Thus, selecting the best candidates for therapeutic de-escalation and choosing the optimal maintenance regimen remain ongoing issues. Clinical trials evaluating therapeutic strategies based on biomarkers, such as circulating tumor DNA, will likely allow for better personalization of maintenance therapy. This review summarizes the main studies and ongoing trials evaluating various maintenance therapy options.