From the Guidelines
Adjuvant chemotherapy in colon cancer significantly improves survival rates and reduces the risk of cancer recurrence, particularly in stage III and high-risk stage II patients. The standard adjuvant chemotherapy regimen for colon cancer is a combination of fluoropyrimidine and oxaliplatin, as demonstrated in the MOSAIC, NSABP C-07, and XELOXA trials, which showed significant improvement in disease-free survival (DFS) compared to fluoropyrimidine monotherapy 1.
Key Points
- The benefit of adjuvant chemotherapy is most pronounced in stage III disease, where it can improve 5-year survival rates by 15-20% 1.
- In high-risk stage II disease, the benefit is smaller but still significant for selected patients, particularly those with poor prognostic features such as T4 tumor, tumor perforation, bowel obstruction, poorly differentiated tumor, venous invasion, or fewer than 10 lymph nodes examined 1.
- Stage I patients generally do not require adjuvant chemotherapy due to their excellent prognosis with surgery alone.
Treatment Regimens
- FOLFOX (5-fluorouracil, leucovorin, and oxaliplatin) is a commonly used regimen, given for 6 months.
- CAPOX (capecitabine plus oxaliplatin) or 5-FU/leucovorin alone can be used for patients who cannot tolerate oxaliplatin.
Timing and Dosing
- Adjuvant chemotherapy should be started within 6-8 weeks after surgery for optimal benefit.
- Typical dosing for FOLFOX includes oxaliplatin 85 mg/m2 IV day 1, leucovorin 400 mg/m2 IV day 1,5-FU 400 mg/m2 IV bolus day 1, then 1200 mg/m2/day IV continuous infusion for 2 days, repeated every 2 weeks. It is essential to individualize treatment decisions based on patient characteristics, disease prognosis, and potential toxicities associated with treatment, particularly in stage II disease 1.
From the Research
Benefits of Adjuvant Chemotherapy
The benefits of adjuvant chemotherapy in colorectal (colon) cancer include:
- Eradicating micrometastases that may be present during the time of surgical resection, reducing the likelihood of disease recurrence and potentially increasing the cure rates after surgery 2
- Improving overall survival and disease-free survival in patients with stage III colon cancer 3, 4, 5
- Potential benefit in patients with high-risk stage II colon cancer, although the evidence is not as clear-cut as for stage III cancer 3, 4, 6
Patient Selection
The decision to use adjuvant chemotherapy should be based on individual patient characteristics, including:
- Stage of cancer: adjuvant chemotherapy is recommended for patients with stage III colon cancer and may be considered for patients with high-risk stage II colon cancer 3, 4, 5
- Age: patients younger than 70 years may derive greater benefit from adjuvant chemotherapy than those older than 70 years 3
- Risk of recurrence: patients with a high risk of recurrence may benefit from more aggressive adjuvant therapy 5, 6
Treatment Regimens
The optimal treatment regimen for adjuvant chemotherapy in colon cancer is:
- Oxaliplatin-based regimen (FOLFOX or CapeOx) for 6 months, which is the current standard of care 2, 3, 4
- Fluoropyrimidine-based regimen alone may be considered for patients with a contraindication to oxaliplatin 2
- The duration of adjuvant chemotherapy may be shortened in some cases, but this should be based on individual patient factors and discussion of the potential benefits and risks 2, 5