Analytic lymph node number establishes staging accuracy by occult tumor burden in colorectal cancer

J Surg Oncol. 2012 Jul 1;106(1):24-30. doi: 10.1002/jso.23051. Epub 2012 Jan 17.


Background and objectives: Recurrence in lymph node-negative (pN0) colorectal cancer suggests the presence of undetected occult metastases. Occult tumor burden in nodes estimated by GUCY2C RT-qPCR predicts risk of disease recurrence. This study explored the impact of the number of nodes analyzed by RT-qPCR (analytic) on the prognostic utility of occult tumor burden.

Methods: Lymph nodes (range: 2-159) from 282 prospectively enrolled pN0 colorectal cancer patients, followed for a median of 24 months (range: 2-63), were analyzed by GUCY2C RT-qPCR. Prognostic risk categorization defined using occult tumor burden was the primary outcome measure. Association of prognostic variables and risk category were defined by multivariable polytomous and semi-parametric polytomous logistic regression.

Results: Occult tumor burden stratified this pN0 cohort into categories of low (60%; recurrence rate (RR) = 2.3% [95% CI 0.1-4.5%]), intermediate (31%; RR = 33.3% [23.7-44.1%]), and high (9%; RR = 68.0% [46.5-85.1%], P < 0.001) risk of recurrence. Beyond race and T stage, the number of analytic nodes was an independent marker of risk category (P < 0.001). When >12 nodes were analyzed, occult tumor burden almost completely resolved prognostic risk classification of pN0 patients.

Conclusions: The prognostic utility of occult tumor burden assessed by GUCY2C RT-qPCR is dependent on the number of analytic lymph nodes.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Colorectal Neoplasms / pathology*
  • Female
  • Humans
  • Logistic Models
  • Lymph Nodes / pathology*
  • Lymphatic Metastasis / diagnosis
  • Male
  • Middle Aged
  • Neoplasm Recurrence, Local / diagnosis
  • Neoplasm Staging
  • Neoplasms, Unknown Primary / pathology*
  • Odds Ratio
  • Polymerase Chain Reaction / methods
  • Predictive Value of Tests
  • Prognosis
  • Prospective Studies
  • Risk Assessment
  • Risk Factors
  • Tumor Burden*