Abstract
Carcinoembryonic antigen (CEA) is a common and widely used tumor marker for clinical diagnosis as well as monitoring of clinical course. We encountered a patient presenting with a transient elevation of the serum CEA level to more than 5–10 ng/ml every summer season, although no recurrence of breast cancer was observed after surgery. The CEA level was positively correlated with the elevation of the weekly average temperature, and a marked increase in CEA level was observed at over 25˚C. The serum alanine transaminase level and red blood cell and hematocrit values were also negatively correlated with the CEA level. In addition, weekly average temperature was found to be the only explanatory variable of the serum CEA level by stepwise regression analysis.
