Premium
Analytic lymph node number establishes staging accuracy by occult tumor burden in colorectal cancer
Author(s) -
Hyslop Terry,
Weinberg David S.,
Schulz Stephanie,
Barkun Alan,
Waldman Scott A.
Publication year - 2012
Publication title -
journal of surgical oncology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.201
H-Index - 111
eISSN - 1096-9098
pISSN - 0022-4790
DOI - 10.1002/jso.23051
Subject(s) - medicine , occult , colorectal cancer , oncology , lymph node , proportional hazards model , cohort , watchful waiting , cancer , radiology , pathology , alternative medicine , prostate cancer
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. J. Surg. Oncol. 2012; 106:24–30. © 2012 Wiley Periodicals, Inc.