Stichting Dutch Colorectal Cancer Group (DCCG)

The goal of this clinical trial is to investigate whether adjuvant chemotherapy can prevent disease recurrence in patients with high-risk rectal cancer who have detectable ctDNA after surgery.
The main research question the REACT study aims to answer is:
- Does adjuvant chemotherapy improve disease-free survival in patients with high-risk rectal cancer with detectable ctDNA after surgery?
Interventions:
- Patients with detectable ctDNA after surgery and randomised to the experimental group will be offered adjuvant chemotherapy (4 cycles CAPOX/6 cycles FOLFOX) within 12 weeks after surgery.

The goal of this phase III, open-label, non-inferiority randomized controlled clinical trial is compare upfront dose-reduced chemotherapy with the standard dose chemotherapy in older patients ( ≥70 years) with metastasized colorectal cancer, with regard to progression-free survival (PFS). The choice between monotherapy (a fluoropyrimidine) and doublet chemotherapy (a fluoropyrimidine with oxaliplatin) will be made for each individual patient based on expected risk of chemotherapy toxicity (according to the G8 screening). Patients classified as low risk of toxicity will be randomized between doublet chemotherapy in either full-dose, or with an upfront dose-reduction of 25%. Patients classified as high risk will be randomized between monotherapy in either full-dose or upfront dose-reduction.
Primary outcome is PFS. Secondary endpoints include grade ≥3 toxicity, QoL, physical functioning, overall survival, number of treatment cycles, dose reductions, hospital admissions, cumulative received dosage and cost-effectiveness.

Irinotecan-based systemic therapy is a treatment option for metastatic or unresectable colorectal cancer. However, this therapy has two major disadvantages, namely, an unpredictable response to the treatment and severe side effects, for instance diarrhea or a low white blood cell count (neutropenia). Therefore, the OPTIMA study was developed to find out if biomarkers, such as the molecular profile of the tumor, the UGT1A1 genotype and activity of the bacterial enzyme β-glucuronidase, can predict response and side effects during irinotecan treatment. By looking at these biomarkers, treatments could be more personalized, resulting into enhanced therapy efficiency, increased optimal survival and a better quality of life.