[Chemotherapy for metastatic colorectal cancer]

The treatment of metastatic colorectal cancer (mCRC) has developed significantly over the past 10 years. For nearly 40 years, the fluoropyrimidine 5-fluorouracil (5-FU) was the only active agent used for advanced metastatic disease. However, since the 1990s, the chemotherapy treatment options for patients with mCRC have been greatly facilitated with the introduction of several new cytotoxic agents. In particular, combination regimens that incorporate infusional schedules of 5-FU in combination with oxaliplatin (FOLFOX) and/or irinotecan (FOLFIRI) have significantly improved clinical efficacy as related to overall response rates, time to tumor progression, and median overall survival. More recently, monoclonal antibodies such as bevacizumab, cetuximab, and panitumumab have become available for use in mCRC treatment in combination with cytotoxic agents and as monotherapies in Western countries. The addition of these target agents to the mCRC treatment armamentarium has resulted in more therapeutic options and improved treatment outcomes for patients. Currently, bevacizumab is the only target drug that is available for mCRC in Japan. In this article we review various treatment options, including cytotoxic and targeted agents, currently available for patients with mCRC in Japan and Western countries.