Background: The clinical usefulness of tumor markers in the follow-up care
of invasive breast cancer is controversial. Methods: In 1228 serum samples
of 664 women with history of breast cancer, the diagnostic accuracy and pre
dictive power of CEA and CA 15-3 for the detection of disease relapse was d
etermined prospectively by analyzing the clinical course for at least 6 mon
ths after the measurement of the tumor markers in 1994. Results: A total of
76 patients relapsed during the period of study. The diagnostic accuracy w
as 83% for CEA and 88% for CA 15-3. CEA and CA 15-3 had a positive predicit
ive value of 27% and 47% as well as a negative prediction of 91% and 93%, r
espectively. Conclusions: The low positive predictive value and sensitivity
of these tumor markers clearly limit their clinical utility. Therefore, th
e effectiveness of routine determinations during the follow-up seems questi
onable.