CEA doubling time
The time required for carcinoembryonic antigen levels to double, used to assess tumor growth rate and treatment response in colorectal cancer.
Full Definition
CEA doubling time is a calculated measure that estimates how quickly carcinoembryonic antigen (CEA) levels increase over time, reflecting tumor burden and growth kinetics in patients with colorectal cancer. This parameter is particularly useful in surveillance after curative resection, where rising CEA levels may indicate recurrent disease. A shorter doubling time (typically less than 3-6 months) suggests more aggressive tumor biology and may prompt earlier intervention or more intensive imaging. The calculation requires serial CEA measurements over time and uses logarithmic formulas to determine the doubling period. CEA doubling time can help guide decisions about timing of salvage surgery for isolated recurrences and has prognostic implications for overall survival.
Usage
Usage note: Express as specific time period (e.g., '3.2 months'); shorter times indicate more aggressive disease.
In Context
- "The CEA doubling time of 2.1 months indicated aggressive recurrent disease, prompting immediate imaging and consideration for salvage therapy." — Oncology follow-up note
- "Patients with CEA doubling times less than 3 months had significantly worse overall survival in the retrospective analysis." — Research study report