Metastatic Colorectal Cancer: Evolution of the Response Rate and Survival with Therapeutic Progress

Introduction: The therapeutic strategy for metastatic colorectal cancer (mCRC) has evolved greatly in the last two decades. This study aimed to compare patients with mCRC treated at the University Hospital of Sousse (Tunisia) through three periods, in terms of treatment strategy; objective response rate (ORR) to chemotherapy; median overall survival (OS) and prognostic factors conditioning OS. Methods: This was a retrospective study covering the period from January 1994 to December 2011. It involved 401 patients with mCRC divided into three groups: group 1 (G1) including patients treated in the period 1994-1998, group 2 (G2) including patients treated in the period 1999-2005 and group 3 (G3) including patients treated in the period 2006-2011. Results: The ORR after 3 cycles of first line chemotherapy was 33%, 50% and 57.8% for G1, G2 and G3 respectively. The median OS was 13.8 months for G1, 19 months for G2 and 23 months for G3. The prognostic factors associated with a better OS for G3 were absence of initial tumor complication, normal initial level of carcinoembryonic antigen, normal liver function tests, surgery of the primary tumor, surgery of liver metastases and the ORR after three cycles of first line chemotherapy. Conclusion: The development of the therapeutic strategy, whatever of medical or surgical nature, has led to improved response rates and survival of patients treated for mCRC.