[Advance of salvage chemotherapy for colorectal cancer]

Oxaliplatin, irinotecan, and 5-fluorouracil in combination with or without targeted therapies are now well-documented treatment options for first- and second-line treatments of metastatic colorectal cancer. Furthermore, many guidelines regard these treatment options as the standard of care of the disease. However, there is much less data on the beneficial effect of salvage systemic therapy. Therefore, salvage treatment for patients with metastatic colorectal cancer after the use of approved drugs or their combinations is reviewed here. Conventional chemotherapeutic agents such as capecitabine, mitomycin C, and gemcitabine have limited or no activity when used as salvage treatment. Antiangiogenic drugs may postpone further progression and prolong survival. Regorafenib and TAS-102 have been established as salvage therapy agents. Further prospective phase III trials comparing an investigational drug alone or in combination with best supportive care as third- or later lines of treatment in metastatic colorectal cancer are highly warranted. Moreover, it is crucial to identify predictive biomarkers and improve our understanding of molecular mechanisms.