Elevated Carcinoembryonic Antigen in Patients with Androgen-Independent Prostate Cancer

Background: Extraordinarily high serum carcinoembryonic antigen (CEA) values have been reported to be associated with many malignant disorders, including carcinoma with primary sites in the colon, pancreas, stomach, bile duct, lung, and breast This study was undertaken to determine if a marked elevation of serum CEA levels in androgen-independent prostate cancer patients exists, and to evaluate the potential of using CEA monitoring as a marker for disease progression. Methods: Records from 141 patients with progressive androgen-independent prostate cancer who were treated at the National Cancer Institute from 1990 to 1996 were analyzed. Serum CEA concentrations were measured using a micro-particle enzyme immunoassay. Results: Among these cases of prostatic carcinoma, 69 (48.9%) had abnormally elevated plasma CEA values (greater than the normal upper limit of 2.5 ng/mL) at some time during their treatment on a clinical investigation protocol. No correlation was found between the elevated CEA concentrations and prostate specific antigen (PSA). In comparison, 32.5% of patients with elevated CEAs had disease that had metastasized to soft tissue (adenopathy, etc) versus 22.2% with normal CEA who had soft tissue involvement (p = 0.3 χ²). We examined the CEA values with respect to survival time, defined as the interval from the date of the earliest CEA level to the date of death and found no association (p > 0.3). Conclusions: Based on these observations, it appears that in the context of androgen-independent prostate cancer, CEA can be elevated but is an inviable surrogate marker of disease progression with minimal prognostic value.