Surgical Endoscopy

, Volume 23, Issue 8, pp 1764–1769 | Cite as

Analysis of patient selection and external validity in the Swedish contribution to the COLOR trial

  • Martin JansonEmail author
  • Gunnar Edlund
  • Ulf Kressner
  • Elisabet Lindholm
  • Lars Påhlman
  • Stefan Skullman
  • Bo Anderberg
  • Eva Haglind



The colon cancer laparoscopic or open resection (COLOR) trial is an international, randomised controlled trial comparing outcomes of open and laparoscopic surgery for colon cancer. The main purpose of this study was to determine representability by comparing included and nonincluded patients in the participating Swedish centres.


At eight centres, which included 391 of the 422 Swedish patients, a local database search was performed to identify retrospectively all patients (n = 2,384) who underwent surgery for colon cancer during the inclusion period, and data was retrieved from medical records.


Four hundred fifty-six patients were randomised, 65 of whom were excluded post randomisation (group 2), leaving 391 patients in the study (group 1). For 1,566 patients, valid exclusion criteria were found (group 3). Thus, 362 patients were eligible but not included (group 4). Relative to group 1, patients in group 4 had a significantly higher American Society of Anaesthesiologists (ASA) score, more advanced tumour stage and difference regarding the resections performed. Results showed that 1470 patients (62%) could be calculated as feasible for laparoscopic colon resection (LCR) in a clinical, nontrial situation.


The study population in the Swedish part of the COLOR trial was representative of the eligible population with the exception of comorbidity, where those actually included had less severe comorbidity than the nonincluded but eligible patients. In Sweden, 50–60% of colon cancer patients can be operated on by laparoscopy.


Colorectal cancer Clinical papers/trials/research Quality control 



The authors are grateful to Marc Buunen, MD, Erasmus Medical Centre, Rotterdam, The Netherlands for providing necessary data from the COLOR trial files and to Harriet Törnqvist for meticulous technical support throughout the study. Professor Eva Haglind (principal investigator) had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.


  1. 1.
    Hazebroek EJ (2002) COLOR: a randomized clinical trial comparing laparoscopic and open resection for colon cancer. Surg Endosc 16(6):949–953PubMedCrossRefGoogle Scholar
  2. 2.
    Veldkamp R, Kuhry E, Hop WC, Jeekel J, Kazemier G, Bonjer HJ, Haglind E, Pahlman L, Cuesta MA, Msika S, Morino M, Lacy AM, Lacy A, Delgado S (2005) Laparoscopic surgery versus open surgery for colon cancer: short-term outcomes of a randomised trial. Lancet Oncol 6(7):477–484PubMedCrossRefGoogle Scholar
  3. 3.
    Kuhry E, Bonjer HJ, Haglind E, Hop WC, Veldkamp R, Cuesta MA, Jeekel J, Pahlman L, Morino M, Lacy A, Delgado S (2005) Impact of hospital case volume on short-term outcome after laparoscopic operation for colonic cancer. Surg Endosc 19(5):687–692. Epub 2005 Mar 30Google Scholar
  4. 4.
    Janson M, Bjorholt I, Carlsson P, Haglind E, Henriksson M, Lindholm E, Anderberg B (2004) Randomized clinical trial of the costs of open and laparoscopic surgery for colonic cancer. Br J Surg 91(4):409–417PubMedCrossRefGoogle Scholar
  5. 5.
    Janson M, Lindholm E, Anderberg B, Haglind E (2007) Randomized trial of health-related quality of life after open and laparoscopic surgery for colon cancer. Surg Endosc 21(5):747–753. Epub 2007 Mar 7Google Scholar
  6. 6.
    Britton A, McKee M, Black N, McPherson K, Sanderson C, Bain C (1999) Threats to applicability of randomised trials: exclusions and selective participation. J Health Serv Res Policy 4(2):112–121PubMedGoogle Scholar
  7. 7.
    King M, Nazareth I, Lampe F, Bower P, Chandler M, Morou M, Sibbald B, Lai R (2005) Conceptual framework and systematic review of the effects of participants’ and professionals’ preferences in randomised controlled trials. Health Technol Assess 9(35):1–186, iii–ivPubMedGoogle Scholar
  8. 8.
    Moher D, Schulz KF, Altman D (2001) The CONSORT statement: revised recommendations for improving the quality of reports of parallel-group randomized trials. JAMA 285(15):1987–1991PubMedCrossRefGoogle Scholar
  9. 9.
    Kennedy WA, Laurier C, Malo JL, Ghezzo H, L’Archeveque J, Contandriopoulos AP (2003) Does clinical trial subject selection restrict the ability to generalize use and cost of health services to “real life” subjects? Int J Technol Assess Health Care 19(1):8–16PubMedCrossRefGoogle Scholar
  10. 10.
    International statistical classification of diseases and related health problems, tenth revision (ICD–10), Swedish Version. The National Board of Health and Welfare, Stockholm (1996)Google Scholar
  11. 11.
    Keats AS (1978) The ASA classification of physical status—a recapitulation. Anesthesiology 49(4):233–236PubMedCrossRefGoogle Scholar
  12. 12.
    Corman M (2005) Colon and rectal surgery, 5th edn. Lippincott, Williams & Wilkins, PhiladelphiaGoogle Scholar
  13. 13.
    Gordon PH, Nivatvongs S (1997) Principles and practice of surgery for the colon, rectum and anus. Quality Medical, St. LouisGoogle Scholar
  14. 14.
    Jestin P (2005) Colorectal cancer. Audit and health economy in colorectal cancer surgery in a defined Swedish population. Uppsala University, UppsalaGoogle Scholar
  15. 15.
    Jestin P, Nilsson J, Heurgren M, Pahlman L, Glimelius B, Gunnarsson U (2005) Emergency surgery for colonic cancer in a defined population. Br J Surg 92(1):94–100PubMedCrossRefGoogle Scholar
  16. 16.
    Bonjer HJ, Hop WC, Nelson H, Sargent DJ, Lacy AM, Castells A, Guillou PJ, Thorpe H, Brown J, Delgado S, Kuhrij E, Haglind E, Pahlman L (2007) Laparoscopically assisted vs open colectomy for colon cancer: a meta-analysis. Arch Surg 142(3):298–303PubMedCrossRefGoogle Scholar
  17. 17.
    COST study group (2004) A comparison of laparoscopically assisted and open colectomy for colon cancer. N Engl J Med 350(20):2050–2059CrossRefGoogle Scholar
  18. 18.
    Guillou PJ, Quirke P, Thorpe H, Walker J, Jayne DG, Smith AM, Heath RM, Brown JM (2005) Short-term endpoints of conventional versus laparoscopic-assisted surgery in patients with colorectal cancer (MRC CLASICC trial): multicentre, randomised controlled trial. Lancet 365(9472):1718–1726PubMedCrossRefGoogle Scholar
  19. 19.
    Lacy AM, Garcia-Valdecasas JC, Delgado S, Castells A, Taura P, Pique JM, Visa J (2002) Laparoscopy-assisted colectomy versus open colectomy for treatment of non-metastatic colon cancer: a randomised trial. Lancet 359(9325):2224–2229PubMedCrossRefGoogle Scholar
  20. 20.
    Leung KL, Kwok SP, Lam SC, Lee JF, Yiu RY, Ng SS, Lai PB, Lau WY (2004) Laparoscopic resection of rectosigmoid carcinoma: prospective randomised trial. Lancet 363(9416):1187–1192PubMedCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2008

Authors and Affiliations

  • Martin Janson
    • 1
    Email author
  • Gunnar Edlund
    • 2
  • Ulf Kressner
    • 3
  • Elisabet Lindholm
    • 4
  • Lars Påhlman
    • 5
  • Stefan Skullman
    • 6
  • Bo Anderberg
    • 7
  • Eva Haglind
    • 4
  1. 1.CLINTEC, Division of SurgeryKarolinska Institutet at Karolinska University Hospital HuddingeStockholmSweden
  2. 2.Department of SurgeryÖstersund HospitalOstersundSweden
  3. 3.Department of SurgeryDanderyd HospitalStockholmSweden
  4. 4.Department of SurgeryInstitute of Surgical Sciences, Göteborg University, Sahlgrenska University HospitalGoteborgSweden
  5. 5.Department of SurgeryUniversity HospitalUppsalaSweden
  6. 6.Department of SurgeryKärnsjukhusetSkovdeSweden
  7. 7.Department of Molecular Medicine and SurgeryKarolinska Institutet, Karolinska University Hospital SolnaStockholmSweden

Personalised recommendations