大腸直腸癌位居全世界癌症死亡原因的第三名。在台灣，大腸直腸癌的發生率逐年上升，2007年更超越肝癌成為發生率最高的癌症，其中，高達1/5的病患是在第四期才被診斷出來。過去接受支持療法的大腸直腸癌病患平均存活期約5-6個月，2000年後，因為多種有效化療藥物上市，轉移性大腸直腸癌病患的存活期迅速延長至一年半。近年來，由於合併使用化療藥物和標革巴藥物，轉移性大腸直腸癌病患 的存活期中位數已達兩年半。本文扼要整理近年治療轉移性大腸直腸癌的重要文獻，討論現今眾多的抗 癌藥物中，如何組合使用、交替轉換或依序使用，以達到治療病患的最佳效果。

Colorectal cancer (CRC) is the third leading cause of cancer-related death worldwide. The incidence of CRC increased gradually in recent years and had became the highest incidence of cancer beyond hepatoma in Taiwan in 2007. Around one fifth patients with CRC are diagnosed in metastatic stage (mCRC). The median overall survival for patients with mCRC who receive best supportive care alone is approximately five to six months. For decades, 5-fluorouracil (5-FU) was the sole active agent for advanced CRC. This has changed markedly since the year 2000, with the approval of irinotecan, oxaliplatin, and five novel targeted agents, including bevacizumab, cetuximab, panitumumab, aflibercept and regorafenib. Systemic chemotherapy produces meaningful improvements in survival that are most pronounced in patients who are exposed to all active drugs, including oxaliplatin, irinotecan, fluoropyrimidines and targeted agents. The median survivals of mCRC patients now far exceed five to six months, going beyond two years. However, the best way to combine and sequence these agents is still not established. This topic summarized the most important data from clinical trials evaluating systemic treatment for mCRC.