Objective: The most common sites of colorectal cancer (CRC) recurrence are the local tissues, liver or lungs. The objective was to identify risk factors associated with the primary CRC tumor and cancer recurrence in these anatomical sites. Methods: Retrospective, longitudinal analyses of data on CRC survivors. Multivariable Cox regression analysis was performed to examine the association between possible cofounders with recurrence to various anatomical sites. Results: Data for 10,398CRC survivors (tumor location right colon = 3870, left colon = 2898, high rectum = 2569, low rectum = 1061) were analyzed; follow up time was up to five years. Mean age at curative surgery was 71.5 (SD 11.8) years, 20.2% received radio-chemotherapy, stage T3 (64.4%) and N0 (65.1%) were most common. Overall 1632 (15.7%) had cancer recurrence (Isolated liver n = 412, 3,8%; isolated lung n = 252, 2,4%; isolated local n = 223, 2.1%). Risk factors associated with recurrent CRC were identified, i.e. isolated liver metastases (male: Adjusted Hazard Ratio (AHR) 1,45; colon left: AHR 1,63; N2 disease: AHR 3,35; T2 disease: AHR 2,82), isolated lung metastases (colon left: AHR 1,53; rectum high: AHR 2,48; rectum low: AHR 2,65; N2 disease 3,76), and local recurrence (glands examined. < 12: AHR 1,51; CRM <3 mm: AHR 1,60; rectum high: AHR 2,15; N2 disease: AHR 2,58) (all p values <0001). Conclusion: Our study finds that the site of the primary CRC tumor is associated with location of subsequent metastasis. Left sided colon cancers have increased risk of metastatic spread to the liver, whereas rectal cancers have increased risk of local recurrence and metastatic spread to the lungs. These results, in combination with other risk factors for CRC recurrence, should be taken into consideration when designing risk adapted post-treatment CRC surveillance programs.
Bibliographical noteFunding Information:
Funding was obtained from the Norwegian Health Authorities (KMA, postdoctoral fellow) and from the Department of Colorectal Surgery, University Hospitals Case Medical Center (KMA and PB). JR was supported for this work in part by a National Cancer Institute Program Grant (5P30CA043703-21) and by American Cancer Society Mentored Research Scholar Grant, No. 124,673-MRSG-13-315-01-CPHPS. The Clinical and Translational Science Collaborative of Cleveland, grant no. UL1TR000439, with support from the National Center for Advancing Translational Sciences (NCATS) component of the National Institutes of Health and NIH roadmap for Medical Research, made this publication possible. Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the NIH.
© 2015 The Authors.