IMMUNOSCORE AS PROGNOSTIC FACTOR IN COLORECTAL CANCER

The "Immunoscore" assay reliably estimates the risk of recurrence in patients with colon cancer, according to an international validation study.

Immunoscore, based on the density of CD3+ and CD8+ T cells within the tumor and its invasive margin, has been shown to predict clinical outcome in patients with early and advanced colorectal cancer.

Dr. Franck Pages from INSERM, Laboratory of Integrative Cancer Immunology and Universite Paris Descartes, in Paris, and colleagues in 13 countries in North America, Europe and Asia joined forces to validate the Immunoscore in clinical practice for patients with stage I-III colon cancer.

Overall, 22% of patients had a low Immunoscore, 51% had an intermediate Immunoscore and 27% had a high Immunoscore, the team reports in The Lancet, online May 10.

Recurrence risk was inversely related to Immunoscore: recurrence at three years was seen in 5% of patients with a high Immunoscore, 17% of patients with an intermediate Immunoscore and 26% of patients with a low Immunoscore.

Overall survival followed a similar pattern: 87% at three years and 82% at five years for patients with a high Immunoscore; 85% and 77%, respectively, for patients with an intermediate Immunoscore; and 76% and 62% for patients with a low Immunoscore.

When stratified into two categories, patients with a high Immunoscore had a significantly longer time to recurrence, overall survival and disease-free survival, compared with patients with a low Immunoscore.

Immunoscore proved valid in each continent.

Immunoscore predicted overall survival better than that of existing tumor risk parameters, including grade of differentiation, microsatellite instability, mucinous colloid type, sidedness, venous emboli, lymphatic invasion and perineural invasion.

Immunoscore had similar predictive accuracy as T stage and N stage, and adding Immunoscore to a model combining all clinical variables significantly improved the prediction for overall survival.

"The reproducibility and robustness of the consensus Immunoscore as a strong prognostic factor in association with the TNM classification system favors its implementation as a new component in the classification of cancer, designated TNM-Immune," the researchers conclude. "This would represent the first standardized immune-based assay for the classification of cancer."

"One outstanding issue that has yet to be resolved is whether the Immunoscore can serve as an actionable predictive biomarker for response to therapy; another issue is the costs, benefits, and feasibility of the Immunoscore as a test in a pathology laboratory workflow," write Dr. Shuji Ogino and Dr. Marios Giannakis from Dana-Farber Cancer Institute, in Boston, in a related editorial. "Additionally, T cells encompass very heterogeneous cell populations, and other immune cells such as natural killer cells, dendritic cells, and macrophages are also important in determining the behavior of cancer cells."

"There is still much to learn about the tumor-immune interactions and the clinical utility of existing and emerging immune biomarkers," they note.

"After clinical utility and cost-effectiveness are proven, the Immunoscore assay could be implemented in clinical settings," the editorial concludes. "Widespread use of high-quality tumor-immune interaction analyses will transform clinical and population studies worldwide, which will eventually contribute to global cancer prevention and control."

Dr. Pages and co-author Dr. Jerome Galon did not respond to a request for comments.

SOURCE: https://bit.ly/2xrzFF7 and https://bit.ly/2kBNnvL

Lancet 2018.