High Immunoscore Associated With Prolonged Time to Recurrence in Colon Cancer
In patients with stage I, II, or III colon cancer, high Immunoscore was associated with significantly longer time to recurrence.
CHICAGO — In patients with stage I, II, or III colon cancer, high Immunoscore was associated with significantly longer time to recurrence, data presented at the 2016 American Society of Clinical Oncology (ASCO) Annual Meeting suggest.1
Previous research has demonstrated that an enhanced lymphocytic reaction may be a prognostic biomarker in patients with colon cancer. With the Immunoscore developed to quantify the in situ immune infiltrate, researchers sought to validate the standardized Immunoscore assay in routine clinical settings.
"There were at least 4 big hurdles in this study," said lead investigator Jerome Galon, PhD, of INSERM at Cordeliers Research Center in Paris, France, during his presentation. "Heterogeneity of patients between centers; heterogeneity of patient care between countries; heterogeneity of IHC (immunohistochemistry) staining between centers; and heterogeneity of clinical data and follow-up between centers."
Dr Galon added that the main objectives were to demonstrate feasibility, reproducibility, significance, and robustness of Immunoscore in a worldwide study.
Researchers enrolled patients with stage I, II, or III colon cancer who had not undergone neoadjuvant therapy. Patients were split into a training set and an internal validation set, and then quantified for the Immunoscore using standardized procedure, immunohistochemistry using CD3 and CD8 antibodies, and quantification using digital pathology on whole slide section of primary tumors.
Across the 23 global pathology expert centers, time to recurrence was shorter among the 548 patients with low-Immunoscore colon cancer compared with the 152 patients with high-Immunoscore cancer in the training set (HR, 0.41; 95% CI, 0.26-0.61; P<.0001), according to the study results.
In the internal validation set, time to recurrence was also shorter among the 481 patients with low-Immunoscore cancer vs the 155 patients with high-Immunoscore cancer (HR, 0.41; 95% CI, 0.27-0.65; P<.0001). Similar results were observed in the external validation cohort. Importantly, results were independent of patient age, sex, tumor stage, and tumor-sidedness in both groups.
"The primary end point of the worldwide prespecified Immunoscore study was reached," Dr Galon said. “Time to recurrence was significantly longer in patients with stage I/II/III colon cancer and high-Immunoscore."
Immunoscore was also determined to be predictive of disease-free survival and overall survival.
The study further demonstrated that among patients with stage II disease in particular, the difference in time to recurrence between low-Immunoscore and high-Immunoscore was significant in both the training set and the validation set, as well as in multivariate analyses.
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"Low-Immunoscore identified a subgroup of patients with high-risk stage II colon cancer," Dr Galon explained.
"The results of this international consortium may result in the implementation of the Immunoscore as a new component for the classification of cancer, designated TNM-I (TNM-Immune)," Dr Galon concluded. "This will represent the first standardized immune-based assay for the classification of cancer."
- Galon J, Mlecnik B, Marliot F, et al. Validation of the Immunoscore (IM) as a prognostic marker in stage I/II/III colon cancer: Results of a worldwide consortium-based analysis of 1,336 patients. J Clin Oncol. 2016; 34 (suppl; abstr 3500).