Impact of lymph node retrieval on surgical outcomes in colorectal cancers

Authors

  • Arun Kritsanasakul MD,

    1. Department of Surgery and Tumor Biology Research Unit, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkhla, Thailand
    Search for more papers by this author
  • Teeranut Boonpipattanapong MD,

    1. Department of Surgery and Tumor Biology Research Unit, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkhla, Thailand
    Search for more papers by this author
  • Worawit Wanitsuwan MD,

    1. Department of Surgery and Tumor Biology Research Unit, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkhla, Thailand
    Search for more papers by this author
  • Monlika Phukaoloun MD,

    1. Anatomical Pathology Unit, Department of Pathology, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkhla, Thailand
    Search for more papers by this author
  • Paradee Prechawittayakul BSc,

    1. Cancer Registry Unit, Songklanagarind Hospital, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkhla, Thailand
    Search for more papers by this author
  • Surasak Sangkhathat MD, PhD

    Corresponding author
    1. Department of Surgery and Tumor Biology Research Unit, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkhla, Thailand
    • Department of Surgery and Tumor Biology Research Unit, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkhla, Thailand 90110. Fax +66 7442 9384.
    Search for more papers by this author

  • Part of the manuscript was originally presented by the first author at the 36th Annual Scientific Meeting of the Royal College of Surgeons of Thailand, jointly held by the American College of Surgeons, July 14–17, 2011, Thailand

Abstract

Background

Adequacy of lymph node sampling is fundamental to the accuracy of nodal status (N-status) assessment in colorectal cancers (CRCs). This study aimed to determine the minimum sampling number to achieve reliable prognosis and to look for any association between the positive lymph node ratio (LNR) and overall survival (OS). Pathological reports of 533 stages I–III CRC patients who underwent curative resection during the period from January 1998 to December 2007 were retrospectively reviewed with regard to the number of lymph nodes obtained for pathological diagnosis (nLN) and number of positive nodes.

Results

The median nLN was 10 nodes and the mean number of positive nodes was 1.7 nodes. On the N-status attribution plot, the cut-off point where the converging curves turned parallel was at 12 nodes. This cut-off was supported by the significant difference in OS between cases with nLN ≥ 12 (5-year OS 73.0%) and those with nLN < 12 (5-year OS 62.7%), (P-value < 0.01). Multivariate analysis showed that both nLN-12 and LNR were independent factors predicting survival probability.

Conclusion

Our data emphasize the importance of lymph node harvesting during the surgical resection of CRCs. In addition, LNR is a strong independent factor associated with CRC survival. J. Surg. Oncol. 2012; 106:238–242. © 2011 Wiley Periodicals, Inc.

Ancillary