Prognosis

The staging of colonic carcinoma is the most important determinant of survival rate and is normally expressed via Dukes classification (1)

• survival rates have improved over time, with almost 60% of people diagnosed with colorectal cancer surviving for at least 5 years
• survival is linked to disease stage at presentation, with better survival the earlier the disease is detected and treated.
• however there are large differences according to the stage of disease. The 5-year survival rate for advanced colorectal cancer is less than 5%. Without treatment, the approximate survival period after diagnosis of metastatic disease is 6-9 months
  
  
• operation for cure can be performed on about 70% of patients:
  • 10% of lesions are not resectable at operation
  • 20% have liver or other distant metastases
• operative mortality rate 2-6% (1)

Spread to lymph nodes

• in the UK, about 26% of patients diagnosed with colorectal cancer are classified as having stage III (Dukes' classification C1 or C2 - tumour has spread to lymph nodes) disease at the time of presentation
• patients have an overall 5-year survival rate of between 25% and 60% (1)
• after a complete surgical resection (undertaken with curative intent), patients with stage III colon cancer have a 50-60% chance of developing recurrent disease (1)

Complications such as obstruction or perforation adversely affect survival. Patients should be followed for recurrent, metastatic, or metachronous lesions. Faecal occult blood should be tested every 6-12 months and colonoscopy performed 1 year after operation. Surgical resection for recurrent lesions should be considered.

Once colorectal cancer has metastasised, the average survival duration without chemotherapy is 3-9 months (1). Systemic chemotherapy is rarely curative in patients with metastatic colorectal cancer except, sometimes, where metastatic disease is confined to the liver and potentially resectable after chemotherapy.

Reference:

1. NICE. Colorectal cancer (management in people aged 18 and over). NG151. 2020, updated December 2021