From the Guidelines
Regular blood work is essential for monitoring patients with a history of colon cancer, and I recommend comprehensive blood tests every 3-6 months for the first 2-3 years after treatment, then every 6 months for years 3-5, and annually thereafter, based on the most recent guidelines from the Chinese Society of Clinical Oncology (CSO) 1. These tests should include:
- A complete blood count (CBC) to check for anemia which might indicate recurrent bleeding
- Liver function tests to detect potential liver metastases
- Carcinoembryonic antigen (CEA) levels which serve as a tumor marker for colorectal cancer CEA levels should be measured every 3-6 months for at least 5 years after diagnosis, with rising levels potentially indicating cancer recurrence, as recommended by the American Society of Clinical Oncology (ASCO) 1. Additional tests may include:
- Comprehensive metabolic panels to assess overall organ function
- Vitamin D levels, as deficiencies are common in cancer patients These monitoring schedules should be adjusted based on individual risk factors, stage at diagnosis, and treatment history, as suggested by the National Comprehensive Cancer Network (NCCN) 1. Regular blood work helps detect recurrence early when treatment options are more effective and provides valuable information about overall health status during recovery from cancer treatment. It is also important to note that the follow-up schedule may vary depending on the stage of the cancer, with more frequent follow-up recommended for patients with stage II or III disease, as stated in the guidelines from the European Society for Medical Oncology (ESMO) 1. Overall, the goal of regular blood work is to detect recurrence early and improve outcomes for patients with a history of colon cancer, as emphasized by the Chinese Society of Clinical Oncology (CSO) 1.
From the Research
Blood Work for Monitoring of Colon Cancer History
- Carcinoembryonic antigen (CEA) is a non-specific serum biomarker that can be used to monitor colon cancer history 2, 3, 4, 5.
- The concentration of CEA is modulated by tumor stage and grade, tumor site in the colon, ploidy status, and patient smoking status 2.
- CEA testing has been shown to detect recurrent colon cancer, but its sensitivity and specificity are limited, with a pooled sensitivity of 59% and specificity of 89% 2.
- Studies have demonstrated that CEA monitoring can detect metastatic disease on average 5 months before routine follow-up evaluation without CEA monitoring detects recurrence 4.
- However, the overall cost-effectiveness of CEA monitoring is not clear, and its role in improving survival rates is still debated 3, 4, 5.
Recommendations for Surveillance
- For patients with stage I-III colon cancer, a medical history and physical examination should be performed every six months for three years, and computed tomography (CT) of the chest-abdomen-pelvis (CT CAP) should be performed at one and three years 6.
- The use of CEA is optional if CT imaging is being performed, and surveillance colonoscopy should be performed one year after the initial surgery 6.
- The frequency of subsequent surveillance colonoscopy should be dictated by previous findings, but generally, colonoscopies should be performed every five years if the findings are normal 6.
Limitations of CEA Monitoring
- CEA testing is not sufficient to improve survival rates, and its use as a single biomarker for early colon cancer recurrence is limited due to its low sensitivity and specificity 2, 3, 4.
- False-positive test results can occur, and CEA elevations may not always indicate cancer recurrence 3.
- The cost-effectiveness of CEA monitoring is not clear, and its use should be weighed against the potential benefits and risks 3, 4.