Influence of the Primary Tumor Location on the Pattern of Synchronous Metastatic Spread in Patients with Stage IV Colorectal Carcinoma, According to the 8 th Edition of the AJCC Staging System.

Background And Aims: The correlations between primary tumor location (right colon cancer - RCC, left colon cancer - LCC and rectal cancer - RC) and the incidence of metastatic sites are scarce and divergent. The current study is the first which compares the pattern of metastatic distribution (M1a: metastasis to one organ/site, excluding peritoneum; M1b: two or more metastatic sites; M1c: peritoneal metastases) between RCC, LCC and RC, respectively.

Methods: All patients operated for colorectal cancer (CRC) between January 2006 and December 2015 were analyzed to assess the primary tumor location, the presence and site of synchronous metastases.