To evaluate the impact of neoadjuvant chemotherapy on disease-free survival in patients with locally advanced colon cancer compared to upfront surgery, specifically focusing on disease-free survival outcomes.
Approach:
Key Findings:
Disease-free survival at 3 years was 87% for the upfront-surgery group and 83% for the neoadjuvant group, with no statistically significant difference.
Overall survival rates at 5 years were 85% for upfront surgery and 87% for neoadjuvant chemotherapy, with 10-year rates of 75% and 81%, respectively.
Neoadjuvant chemotherapy was feasible and associated with pathologic downstaging, but only 3% achieved a complete pathologic response.
The positive predictive value of CT for identifying high-risk disease was 59%, indicating potential misclassification.
Exploratory analyses suggested heterogeneity in outcomes based on mismatch repair status, with significant differences in disease-free survival.
Interpretation:
The NeoCol trial indicates that neoadjuvant chemotherapy does not provide a clear benefit over upfront surgery in terms of disease-free survival for locally advanced colon cancer, though it may have advantages in specific patient subgroups.
Limitations:
Lower-than-expected number of events limited statistical power.
Modest accuracy of CT for risk stratification.
Limited generalizability beyond predominantly fit patients in Scandinavian health systems.
Mismatch repair status was not routinely assessed at trial initiation.
Conclusion:
Further studies are needed to explore individualized treatment approaches using biomarkers such as mismatch repair status and improved imaging techniques to better define the role of neoadjuvant therapy in colon cancer.
