A new study suggests that treatment for Stage III Colon Cancer may need to be more personalized. Standard care usually includes surgery followed by adjuvant chemotherapy, such as CAPOX or Capecitabine, but about 30% of patients still experience cancer recurrence. Researchers analyzed 259 patients to identify biological markers that may predict which tumors will resist these treatments.
The study focused on circulating tumor DNA (ctDNA) to detect minimal residual disease, meaning small amounts of cancer that remain after surgery. Two major indicators of poor response to chemotherapy were identified. Patients with a high level of Cancer-Associated Fibroblasts (CAF) had a very high risk of recurrence, with 92% of patients in this group relapsing despite chemotherapy. Mutations in the SMAD4 gene were also linked to worse outcomes and possible resistance to common chemotherapy drugs.
Researchers also found that other tumor features, including mesenchymal traits and certain immune patterns, were associated with higher recurrence risk. The findings suggest that advanced genetic and RNA-based testing may help doctors identify patients who need more aggressive or experimental treatments, while others with lower risk could potentially receive less chemotherapy.