Immunoscore predicts outcomes in localized colon cancer

In patients with localized colon cancer, a low Immunoscore is indicative of poorer clinical outcomes, particularly disease-free and overall survival, suggest the results of a Philippines study presented at the recent ESMO GI 2023.

“The use of Immunoscore provides valuable estimate of the risk of recurrence in patients with early colon cancer and has the potential to greatly affect treatment decisions in conjunction with the existing risk assessment system,” said researchers J Padayao and C Dy from St Luke’s Medical Center, Quezon City, Philippines.

To assess the prognostic value of Immunoscore in predicting clinical outcomes, Padayao and Dy performed a systematic search of observational or randomized controlled studies using PubMed, Embase, and Cochrane CENTRAL Library from January 2008 to December 2022.

Studies examining the relationship between Immunoscore and long-term prognosis (ie, disease-free and overall survival) in patients with localized colon cancer were included.

The researchers extracted hazard ratios (HR) with 95 percent confidence interval (CI) for disease-free and overall survival. They also obtained the pooled estimates of the prognostic ability of Immunoscore using bivariate random effects model. Finally, heterogeneity between studies was assessed using I2 statistics and examined via sensitivity analysis.

Eleven studies including a total of 5,718 patients met the eligibility criteria. Heterogeneity was moderate between studies for both disease-free (I2, 27 percent) and overall survival (I2, 33 percent). [ESMO GI 2023, abstract P-392]

Pooled analysis revealed that colon cancer patients with low Immunoscore had shorter disease-free survival (HR, 1.75, 95 percent CI, 1.53‒2.49) and overall survival (HR, 1.87, 95 percent CI, 1.45‒2.13) compared with those with high Immunoscore. This finding was consistent across geographic regions and maximum time of follow-up in subgroup analyses.

“Robust data in colorectal tumour research show the value of tumour microenvironment and tumour-infiltrating lymphocytes as novel parameters to predict recurrence and survival,” the researchers said.

“The utility of the derived tumour Immunoscore via digital pathology is now being promoted to refine the prognosis of early colon cancer patients together with the TNM staging to guide treatment decisions but is not yet a recommendation in international consensus guidelines,” they added.

Response prediction

In another study, Immunoscore predicted response to chemotherapy among patients with locally advanced colon cancer. Specifically, those with a high Immunoscore benefited significantly from chemotherapy. [Oncoimmunology 2020;9:1826132]

Two independent phase III trials (NCCTG and Prodige-IDEA) confirmed the prognostic value of Immunoscore. In addition, the predictive value of Immunoscore for response to adjuvant FOLFOX chemotherapy duration was observed in the IDEA trial. [Oncoimmunology 2020;9:1826132]

“The latest edition of the WHO Digestive System Tumors classification introduced the immune response as measured by Immunoscore as essential and desirable diagnostic criteria for colon cancer, and Immunoscore was introduced into the 2020 ESMO Clinical Practice Guidelines for Colon Cancer to refine the prognosis and adjust chemotherapy decision-making process in stages II and III patients,” the authors said.