JNCI Cancer Spectr 2020 Jun 5;4(3):pkaa023. Epub 2020 Apr 5.
Division of Oncology, Department of Medicine, Mayo Clinic, Rochester, MN, USA.
Background: The American Joint Committee on Cancer staging and other prognostic tools fail to account for stage-independent variability in outcome. We developed a prognostic classifier adding Immunoscore to clinicopathological and molecular features in patients with stage III colon cancer.
Methods: Patient (n = 559) data from the FOLFOX arm of adjuvant trial NCCTG N0147 were used to construct Cox models for predicting disease-free survival (DFS). Variables included age, sex, T stage, positive lymph nodes (+LNs), N stage, performance status, histologic grade, sidedness, , mismatch repair, and Immunoscore (CD3, CD8 T-cell densities). After determining optimal functional form (continuous or categorical) and within Cox models, backward selection was performed to analyze all variables as candidate predictors. All statistical tests were two-sided.
Results: Poorer DFS was found for tumors that were T4 vs T3 (hazard ratio [HR] = 1.76, 95% confidence interval [CI] = 1.19 to 2.60; = .004), right- vs left-sided (HR = 1.52, 95% CI = 1.14 to 2.04; = .005), (HR = 1.74, 95% CI = 1.26 to 2.40; < .001), mutant (HR = 1.66, 95% CI = 1.08 to 2.55; = .02), and low vs high Immunoscore (HR = 1.69, 95% CI = 1.22 to 2.33; = .001) (all <.02). Increasing numbers of +LNs and lower continuous Immunoscore were associated with poorer DFS that achieved significance (both s<.0001). After number of +LNs, T stage, and , Immunoscore was the most informative predictor of DFS shown multivariately. Among T N tumors, Immunoscore was the only variable associated with DFS that achieved statistical significance. A nomogram was generated to determine the likelihood of being recurrence-free at 3 years.
Conclusions: The Immunoscore can enhance the accuracy of survival prediction among patients with stage III colon cancer.