- In 2018, approximately 97,000 people living in the United States will be diagnosed with colon cancer. Of these patients, just less than one-third will have stage III disease, characterized by spread to regional lymph nodes and absence of distant metastases.
- The primary treatment option for patients with stage III colon cancer is resection with curative intent, however recurrence rates can be as high as 50–80% with surgery alone.
- Adjuvant chemotherapy is recommended to improve overall survival for patients who have a high risk of recurrence.
For patients with stage III resected colon cancer who are being offered treatment with oxaliplatin-containing chemotherapy:
- For patients with high risk (T4 and/or N2) stage III resected colon cancer, adjuvant oxaliplatin-containing chemotherapy should be offered for a duration of six months. (Moderate Recommendation; EB-I-B)
- For patients with low risk (T1, T2, or T3 and N1) stage III resected colon cancer, adjuvant oxaliplatin-containing chemotherapy may be offered for a duration of three months or six months, after a discussion with the patient of the potential benefits and risks of harm associated with the options for treatment duration. (Moderate Recommendation; EB-I-B)
- A shared decision-making approach should be used for duration of oxaliplatin-containing chemotherapy for patients with stage III resected colon cancer, taking into account a patient’s tumor characteristics, completeness of surgical resection, number of lymph nodes examined, comorbidities, functional status, performance status, values and preferences, age at diagnosis, life expectancy, potential years at risk for long-term sequalae of treatment, and including a discussion of the potential for benefit and risks of harm associated with treatment duration (Strong Recommendation; CB-B)
Summary of Key Evidence from the International Duration Evaluation of Adjuvant Chemotherapy (IDEA) Collaboration (n = 12,834):
- Using a predefined threshold, noninferiority of three months compared to six months of oxaliplatin-containing chemotherapy was not proven for disease-free survival (DFS), the primary outcome.
- The relative risk of all grade 3-4 adverse events, and grade 3-4 peripheral sensory neurotoxicity up to one month post-treatment was significantly lower with three months vs. six months of dual agent chemotherapy.
Exploratory subgroup analyses by risk of recurrence:
- Within the high-risk group defined in the IDEA Collaboration (T4 and/or N2), superior DFS was found with 6 months versus 3 months duration of dual-agent chemotherapy.
- Within the low-risk group (T1 to 3, N1), DFS was noninferior with 3 months versus 6 months duration of dual-agent chemotherapy.
Prespecified subgroup analysis by type of oxaliplatin-based chemotherapy:
- 3 months of treatment was not inferior to 6 months for patients treated CAPOX.
- 3 months of treatment was found to be inferior to 6 months for patients treated with FOLFOX.
Reference: Grothey A, Sobrero AF, Shields AF, et al: Duration of adjuvant chemotherapy for stage III colon cancer. N Engl J Med 378:1177-1188, 2018.