OPTIMIzation of Treatment SElection and Follow up in Oligometastatic Colorectal Cancer

Patients will be offered adjuvant chemotherapy according to standard of care. Follow up will be performed with imaging according to standard guidelines, equal to the experimental arm. Blood samples will be analyzed retrospectively to evaluate the ctDNA status.

Circulating tumor-marker positivity will lead to escalation with 6 months of intensified chemotherapy consisting of 4 months of FOLFOXIRI followed by 2 months of 5FU monotherapy. Circulating tumor-marker negativity will based on shared decision-making lead to de-escalation i.e. possibilities for observation in patients otherwise eligible for monotherapy or observation/monotherapy in patients, otherwise eligible for combination chemotherapy according to standard of care.