Revised 05 Sept 2012

Stage 0

Cancer is limited to mucosa without invasion of the lamina propria

• Endoscopic polypectomy with clear margins.
• Segmental colectomy for lesions not amenable to local excision. 

Stage I: T1-2, N0, M0

• Segmental colectomy.
• No role for adjuvant chemotherapy or radiotherapy. 

Stage II: T3-4, N0, M0

• Segmental colectomy.
• The potential value of adjuvant chemotherapy for unselected patients with stage II colon cancer remains controversial.
• Accepted high risk features associated with an increased risk of recurrence in patients with stage II colon cancer include: inadequate lymph node sampling (<12 nodes), T4 disease, clinical perforation, complete obstruction and poor differentiation.
• The presence of high levels of tumour microsatellite instability (MSI-H) is associated with a favourable prognosis and lack of benefit with adjuvant 5FU chemotherapy in this setting. MSI-H is present in an estimated 20% of stage II colon cancers and is associated with clinical features of female gender, proximal colon location, poorly differentiated mucinous histology and the presence of tumour infiltrating lymphocytes. Patients with stage II MSI-H colon cancer should not be offered adjuvant chemotherapy.
• Early referral for a consultation with a medical oncologist for assessment and discussion of adjuvant chemotherapy for patients with stage II colon cancer is highly recommended. Adjuvant chemotherapy should start as close to four weeks post-op as possible.
• Appropriately selected patients with high-risk T3N0 (stage IIA) colon cancer may be candidates for 6 months of adjuvant capecitabine (GIAJCAP).
• Appropriately selected patients with T4N0 (stage IIB) colon cancer may be candidates for 6 months of capecitabine (GIAJCAP) or modified FOLFOX6 (GIAJFFOX) per oncologist’s discretion.
• Consider treatment on a clinical trial, if available.
• No role for adjuvant radiotherapy. 

Stage III low-risk: T1-3, N1, M0

• Segmental colectomy.
• 3 months of adjuvant 5-fluorouracil and oxaliplatin chemotherapy is recommended.  A duration of 3 months has been demonstrated to have comparable efficacy in low-risk stage III disease with less neurotoxicity when compared to the previous standard of 6 months of oxaliplatin-containing chemotherapy (ASCO stage III guideline 2019, IDEA Final results update, ASCO 2020).
• Adjuvant chemotherapy should start as close to four weeks post-op as possible.
• Standard of care options include  3 months of CAPOX (4 cycles) or modified FOLFOX6 (6 cycles). 3 months of oxaliplatin-containing chemotherapy is associated with significantly less neurotoxicity. For patients treated with mFOLFOX6, treatment for greater than 3 months (to maximum of 6 months) may be considered if the treating oncologist feels the benefits outweigh the risks.
  
• For patients unsuitable for oxaliplatin,6 months of capecitabine would be offered
  
• Please refer to current treatment protocols for indications, dosing and eligibility criteria.
• Consider treatment on a clinical trial, if available.
• No established role for adjuvant radiotherapy. 

Stage III high-risk: T4 and/or N2, M0

• Segmental colectomy.
• Six months of adjuvant 5-fluorouracil and oxaliplatin chemotherapy has been demonstrated in multiple randomized studies to improve disease-free and overall survival in patients with stage III colon cancer.
• Adjuvant chemotherapy should start as close to four weeks post-op as possible.
• Standard of care options include 6 months CAPOX (8 cycles) or modified FOLFOX6 (12 cycles), or 6 months of capecitabine alone (for patients unsuitable for oxaliplatin).
• Please refer to current treatment protocols for indications, dosing and eligibility criteria.
• Consider treatment on a clinical trial, if available.
• No established role for adjuvant radiotherapy. 

Stage IV: any T, any N, M1

• Segmental resection (with or without anastomosis) or proximal diversion of obstructing or bleeding primary tumours in selected patients
• Resection or ablation of isolated metastases: liver or lung in selected patients; referral to BC Cancer for multi-disciplinary assessment is recommended.
• Palliative radiation therapy or stereotactic body radiation therapy (SBRT) in selected patients.
• Palliative chemotherapy has been shown to significantly improve survival in patients with unresectable metastatic colorectal cancer achieving an estimated median overall survival of 24 to 28 months as compared to less than 6 months with supportive care alone. Currently approved chemotherapeutic agents for metastatic colon cancer include: capecitabine, 5-fluorouracil (5-FU), irinotecan and oxaliplatin.
• The most commonly used regimens are:

1. oxaliplatin with 5-FU (FOLFOX) or capecitabine (CAPOX)
2. irinotecan with 5-FU (FOLFIRI) or capecitabine (CAPIRI)
3. capecitabine monotherapy

• The choice and sequence of chemotherapy is determined by disease-related factors, patient factors and patient preferences as assessed by the medical oncologist.
• Currently approved targeted therapies include: bevacizumab, cetuximab, and panitumumab.
• Bevacizumab is recommended for use in combination with first-line FOLFIRI chemotherapy (FOLFOX may be considered in selected circumstances). It may also be considered for use in combination with second-line doublet chemotherapy for those patients who did not receive it in first-line.
• Cetuximab or panitumumab is indicated in patients with previously treated metastatic colorectal cancer with wild-type K-ras gene (i.e. tumour K-ras gene is not mutated).
• Please refer to current treatment protocols for indications, dosing and eligibility criteria.
• Consider treatment on a clinical trial, if available.
• Symptom management, best supportive care, and involvement of palliative care services as indicated by patient’s clinical status.