In a study reported in the Journal of Clinical Oncology, Mlecnik et al found that high Immunoscore values were associated with reduced risk of disease recurrence and better outcomes with chemotherapy vs no chemotherapy in patients with stage III colon cancer.
Study Details
The international study—led by the Society for Immunotherapy of Cancer—evaluated the predefined consensus Immunoscore in 763 patients with stage III colon cancer in two cohorts: one comprised of patients from Canada and the United States, and the other including patients from Europe and Asia. No patients had received immune checkpoint therapy. The primary outcome measure was association of Immunoscore with time to recurrence.
“This study shows that a high Immunoscore [is] 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.”— Mlecnik et al
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Key Findings
Patients with a high Immunoscore (70%–100%) had the lowest risk of disease recurrence in both cohorts.
For the combined cohorts, recurrence-free rates at 5 years were 49.6%, 63.2%, and 69.4% in patients with low (0%–25%), intermediate (25%–70%), and high Immunoscores. Hazard ratios (HR) were 0.48 (P = .0003) for high vs low score and 0.69 (P = .0096) for intermediate vs low score.
High Immunoscore was associated with prolonged time to recurrence among patients with microsatellite-stable disease (HR for high vs low = 0.36, P = .0003).
Patients with high Immunoscores had significantly prolonged 5-year overall survival (HR = 0.6, P = .0022) and disease-free survival (HR = 0.62, P = .0014) compared to patients with low Immunoscores.
On multivariate analysis, Immunoscore was significantly associated with time to recurrence (HR for high vs low = 0.41, P = .0003) independent of sex, T stage, N stage, sidedness, and microsatellite instability status.
Among patients with intermediate or high Immunoscores, receipt of adjuvant chemotherapy vs no chemotherapy was associated with significantly prolonged time to recurrence among both high-risk patients (HR = 0.5, P = .0015) and low-risk patients (HR = 0.42, P = .0011). No such association for chemotherapy was found among patients with low Immunoscore for either high-risk (P = .12) or low-risk patients (P = .17).
The investigators concluded, “This study shows that a high Immunoscore [is] 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.”
Jérôme Galon, PhD, of INSERM, Laboratory of Integrative Cancer Immunology, Cordeliers Research Center, Paris, is the corresponding author for the Journal of Clinical Oncology article.
Disclosure: The study was supported by the Society for Immunotherapy of Cancer and others. For full disclosures of the study authors, visit ascopubs.org.
