High Immunoscore Linked to Prolonged Survival in Stage III Colon Cancer

An international study conducted by the Society for Immunotherapy of Cancer evaluated the prognostic value of Immunoscore in patients with stage III colon cancer found that patients with a higher Immunoscore benefit the most from chemotherapy in terms of recurrence risk (J Clin Oncol. 2020 Sep 8:JCO1903205.).

Bernhard Mlecnik, PhD, Laboratory of Integrative Cancer Immunology, Paris, France, and colleagues evaluated the predefined consensus Immunoscore in 763 patients between 2 cohorts, with American Joint Committee on Cancer/Union fromInternational Cancer Control TNM stage III colon cancer from cohort 1 (Canada/United States) and cohort 2 (Europe/Asia). Through the use of digital pathology, CD3+ and cytotoxic CD8+ T lymphocyte densities were quantified in the tumor and invasive margin. 

The primary end point of this study was time to recurrence (TTR), secondary endpoints included overall survival (OS), disease-free survival (DFS), prognosis in microsatellite stable (MSS) status, and predictive value of efficacy of chemotherapy.

After three years, the recurrence-free rate in patients with low Immunoscores was 56.95% (95% CI, 50.3%-64.4%), compared to 65.9% (95% CI, 60.8% to 71.4%) and 76.4% (95% CI, 69.3%-84.3%) in those with medium and high Immunoscores, respectively (hazard ratio [HR; high vs low], 0.48; 95% CI, 0.32-0.71; P = .0003). 

Research shows a high Immunoscore was linked to a prolonged OS and DFS, as well as TTR (all P <.001). Furthermore, Immunoscore association with TTR (HR [high vs low], 0.41; 95% CI, 0.25-0.67; P = .0003) was independent of patients sex, T stage, N stage, sidedness, and microsatellite instability status. A connection between high Immunoscore and prolonged TTR was also found among MSS patients HR [high vs low], 0.36; 95% CI, 0.21-0.62; P = .0003), 

Of note, Immunoscore had the strongest contribution χ2 proportion for influencing survival (TTR and OS), as well as a significant association between chemotherapy and survival in the high-Immunoscore group for both low-risk (HR [chemotherapy vs no chemotherapy], 0.42; 95% CI, 0.25-0.71; P = .0011) and high-risk (HR [chemotherapy vs no chemotherapy], 0.5; 95% CI, 0.33-0.77; P = .0015) patients.

“This study shows that a high Immunoscore significantly associated with prolonged survival in stage III [colon cancer]. Our findings suggest that patients with a high Immunoscore will benefit the most from chemotherapy in terms of recurrence risk,” concluded Dr Mlecnik et al.—Alexandra Graziano