Abstract
BACKGROUND.
The heterogeneity of stage II colon cancer underlines the need for identifying high‐risk, lymph node‐negative patients. The objective of this study was to define a multimarker prognostic model of 5‐year survival in patients with lymph node‐negative, mismatch repair (MMR)‐proficient colorectal cancer (CRC).
METHODS.
Immunohistochemistry for 13 tumor markers was performed on 587 lymph node‐negative, MMR‐proficient CRC samples by using a tissue microarray. Immunoreactivity was evaluated semiquantitatively. A receiver‐operating characteristic‐based approach was used to detect clinically relevant tumor markers and to determine cutoff scores for tumor positivity. Univariate and multivariate analyses stratified by pathologic T3 (pT3) or pT4 tumor classification were performed.
RESULTS.
In univariate analysis, the absence of CD8+ tumor infiltrating lymphocytes (TILs) (P < .001), loss of p27 (P = .006), positive urokinase‐type plasminogen activator (uPA) expression (P = .002), and positive uPA receptor (uPAR) expression (P = .037) were associated with an adverse prognosis. In multivariate analysis, CD8 (P = .001), p27 (P = .031), and uPA (P = .014) were independent prognostic factors. The multimarker phenotype of negative CD8, loss of p27, and positive uPA expression led to significantly worse survival compared with all other combinations of these features. Stratified by pT3 or pT4 stage, CD8 (P = .006) and uPA (P = .011) had independent prognostic value. Combined CD8 negativity and uPA positivity led to a more adverse prognosis in both patients with pT3 tumors and patients with pT4 tumors (P < .001). No difference was observed in the length of survival between patients with pT3 tumors who had CD8 negativity and uPA positivity and patients with pT4 tumors (P = .267).
CONCLUSIONS.
The multimarker phenotype of the absence of CD8+ TILs, loss of p27, and positive uPA expression was predictive of an adverse prognosis in patients with lymph node‐negative, MMR‐proficient CRC. The current findings suggested that a subgroup of patients with high‐risk, lymph node‐negative pT3 tumors should be considered for adjuvant therapy. Cancer 2008. © 2007 American Cancer Society.