From the Guidelines
Surgery alone is not recommended for low-risk stage 3 colon cancer due to the significant survival benefit provided by adjuvant chemotherapy. The 5-year survival rate for patients with stage 3 colon cancer who undergo surgery alone is approximately 50-60%, compared to 65-75% for those who receive surgery plus adjuvant chemotherapy 1. Even in low-risk stage 3 disease (T1-3, N1), adjuvant chemotherapy typically provides an absolute survival benefit of 10-15%.
Key Considerations
- The standard recommendation is for surgery followed by 3-6 months of adjuvant chemotherapy, usually with regimens like CAPOX (capecitabine plus oxaliplatin) or FOLFOX (5-fluorouracil, leucovorin, and oxaliplatin) 1.
- For low-risk patients (T1 to 3, N1), 3 months of adjuvant oxaliplatin and fluoropyrimidine–based therapy may be considered, as suggested by an unplanned subgroup analysis 1.
- A shared decision approach is recommended when deciding on the duration of therapy, weighing the benefit of adjuvant therapy against the toxicity of the therapy 1.
Special Considerations
- For elderly patients (>80 years) or those with significant comorbidities who may not tolerate combination therapy, single-agent capecitabine or 5-FU might be considered 1.
- In very select cases with significant comorbidities, surgery alone might be discussed after careful consideration of risks and benefits 1.
From the Research
Survival in Low-Risk Stage 3 Colon Cancer with Surgery Alone
- The study 2 found that radical surgery alone did not provide enough treatment for colon cancer with very low lymphatic tumor burden, and adjuvant chemotherapy was significantly associated with improved prognosis.
- The 5-year cause-specific survival rates of patients without and with adjuvant chemotherapy were 80.0 and 90.7%, respectively, indicating a significant benefit of adjuvant chemotherapy in stage III colon cancer.
- Another study 3 found that the use of FLOX/OX (5-fluorouracil, leucovorin, and oxaliplatin) was associated with improved overall survival in stage II and III patients, and improved cancer-specific survival in stage III patients compared with 5-FU/LV.
Factors Affecting Treatment Decisions
- A study 4 found that physicians' reasons for not recommending adjuvant chemotherapy for stage III colon cancer included presence of one or more co-morbidities (34%) or combination of co-morbidity and age or frailty (22%).
- Patients' reasons for refusing chemotherapy included concerns about toxicity (22%) 4.
- The study 5 found that mismatch repair (MMR) status and BRAF mutation were important factors in determining the benefit of adjuvant chemotherapy, with MMR-deficient tumors having a poorer prognosis.
Adjuvant Chemotherapy Regimens
- The study 3 compared the use of 5-FU/LV, capecitabine, and FLOX/OX in stage II and III colon cancer patients, and found that FLOX/OX was associated with improved overall survival.
- The study 5 found that the addition of oxaliplatin to fluorouracil and leucovorin (FOLFOX4) improved overall survival in stage II to III colon cancer patients, with a 10-year overall survival rate of 71.7% compared with 67.1% for the LV5FU2 arm.