Supplementing standard adjuvant chemotherapy with atezolizumab immunotherapy significantly improves treatment outcomes in patients with certain forms of colorectal cancer after surgery. This is shown by the international ATOMIC study (Alliance A021502/AIO-KRK-0317), which was coordinated in Germany by Prof. Dr. Anke Reinacher-Schick from St. Josef Hospital, Klinikum der Ruhr-Universität Bochum. The results are published in the “New England Journal of Medicine” on March 26, 2026.

The study enrolled a total of 712 patients with stage III dMMR colorectal cancer after surgery between September 2017 and January 2023. dMMR stands for “deficient DNA mismatch repair” and characterizes a tumor form with a particularly large number of mutations. Participants were randomly divided into two groups: one received six months of standard chemotherapy alone, the other received chemotherapy in combination with atezolizumab, followed by another six months of atezolizumab as monotherapy.

After three years, 86.3 percent of patients in the combination group were disease-free, compared to only 76.2 percent in the chemotherapy group alone. The risk of recurrence of the disease or death was thus reduced by 50 percent.

The study thus establishes a new standard of care for this biologically distinguishable subgroup of early-stage colorectal cancer patients. The results have already been included in the latest guidelines of the National Comprehensive Cancer Network.

The German participation in the study was carried out in close cooperation between the US Alliance for Clinical Trials in Oncology and the Working Group on Internal Oncology (AIO) of the German Cancer Society under the national leadership of Anke Reinacher-Schick. AIO study centers enrolled patients in the later phase. The rapid recruitment of suitable patients in Germany has been significantly facilitated by the AIO’s COLOPREDICT Registry (CPP Registry).

The global study was funded by the US National Cancer Institute (NCI) and led by the Alliance. Genentech, a member of the Roche Group, supported them as part of a collaborative research agreement. The U.S. principal investigator was Prof. Dr. Frank A. Sinicrope of the Mayo Clinic.

Original paper:

Atezolizumab plus FOLFOX for Stage III Mismatch Repair–Deficient Colon Cancer | New England Journal of Medicine

Editor: X-Press Journalistenbüro GbR

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